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1. code there are several novam in Surface Observation and Radiosonde Profile files The tape5 used to run MODTRAN with NOVAM aerosols for the calculations in this report is shown below The N in the third line invokes the NOVAM aerosol option in MODTRAN T 6 2 2 1 0 0 0 0 0 0 i 0 a 0500 F OF 0 1N 0 0 0 0 0 0 000 000 000 000 0050 0000 10 180 00000 2 2 0 0 45 60 Fo 4 0001 0010 M1 First NOVAM is executed to produce the novam out file This file then should be copied to the directory containing the MODTRAN executable as NOVAM OUT MODTRAN requires this file with the uppercase name B 5 Future Upgrades to NOVAM Implementation There are at least six general areas in which the aerosol product in MODTRAN can be improved 1 The first is to enable NOVAM to run from MODTRAN s input file tapeS This task will enable MODTRAN to use radiosonde data consisting of several hundred altitude layers several of which can even be redundant This will alleviate the need for NOVAM to have its own input file as is required in the current input scheme Note that there still may be a need for the NOVAM input file for example to input surface observations 2 MODTRAN does not now have phase functions for several aerosols e g the desert aerosols and for none of the cloud models In the future this can be rectified by generation of the phase functions using the Mie code and incorporating them in MODTRAN 3 The phase functions for NOVAM a
2. number of spectral grid points for aerosol N CARD 2D2 is the list of the spectral parameters VARSPC is the wavelength in microns EXTC is the extinction coefficient ABSC is the absorption coefficient and ASYM is the asymmetry parameter Previously the IREG values were all 1 or 0 A value of 1 meant that spectral parameters had to be read using CARD 2D2 and the number of spectral points were fixed at 47 Actually the VARSPC array was not used at all because the 47 wavelengths were already fixed in the code at an earlier point Now VARSPC is a 2D array the first dimension identifies the aerosol and the second is the wavelength index The user must input VARSPC values in microns and in increasing order that is the first VARSPC must be the lowest wavelength The VARSPC array may differ for each aerosol The meaning of IREG is summarized and further clarified below 75 Appendix A User Supplied Aerosol Parameters VALUE OF ARUSS VALUE AND MEANING OF IREG N ARUSS USS IREG N 0 No user supplied data IREG N M _ User supplied data for M arbitrary wavelengths ARUSS blank IREG N 0 Nouser supplied spectral data IREG N 1 User supplied data for the 47 fixed grid points of Table 10 Although VARSPC array is read they are not used instead Table 10 wavelengths are used A 2 User Supplied Aerosol Phase Functions CARDs 3B 1 3B2 3C1 3C6 The user supplied phase function input scheme has also been upgraded As before the us
3. 70 00 50 00 50 00 CARD 2A 1 0194 44735 1 1149 03721 90502 03577 62886 11468 67765 10404 36239 15033 67035 20663 60029 25834 80838 34487 62531 23290 48791 18807 44203 18161 40179 25847 0 000 0500 8857 7143 8936 9247 8524 9038 7748 STILT 6558 6805 6700 6366 5494 Appendix B NOVAM APPENDIX B NOVAM IN MODTRAN The most recent compilation of the NOVAM Navy Oceanic Vertical Aerosol Model profiles offers a new set of aerosol descriptions providing both optical and size distributions appropriate from the shipboard surface to 6 km covering the spectral range from 0 2 micron to 40 microns at relatively sparse spectral resolution Since the ozone retrievals currently implemented in the UV encompass an accounting of the aerosol background the addition of NOVAM profiles to MODTRAN was deemed critically important B 1 NOVAM Code Spectral Sciences Incorporated SSI obtained the NOVAM code from NRaD through S Gathman Gathman and Davidson 1993 R A Paulis released this code under the authority of J H Richter Oceanic and Atmospheric Sciences Division Naval Command Control and Ocean Surveillance Center San Diego The NOVAM code is an upgrade to NAM Navy Aerosol Model which is already in MODTRAN NOVAM is based on extensive direct shipboard measurements carried out by several different agencies specializing in the marine environment The inputs to the NOVAM co
4. CARD 2 is not set to USS Instructions for the MODTRAN3 7 MODTRAN4 upgrade ARUSS USS are provided in Appendix A 15 1 CARD 3B1 CARD 3B1 NANGLS If IPH 1 on CARD 3A1 FORMAT 15 NANGLS number of angles for the user defined phase functions maximum of 50 15 2 CARD 3B2 This card is repeated NANGLS times 1 to NANGLS CARD 3B2 ANGF FC I 1 F 2 I 1 FG I 1 FG I 1 I 1 NANGLS FORMAT 5E10 3 ANGF I scattering angle in decimal degrees 0 0 to 180 0 Fd 1 1 Normalized user defined aerosol scattering phase function at ANGF boundary layer 0 to 2 km default altitude region srt F 2 I 1 Normalized user defined aerosol scattering phase function at ANGEF I troposphere 2 to 10 km default altitude region srt FG LD Normalized user defined aerosol scattering phase function at ANGFO stratosphere 10 to 30 km default altitude region srt F4 L1 Normalized user defined aerosol scattering phase function at ANGF mesosphere 30 to 100 km default altitude region sr The default altitude regions may be overridden by the parameters IHA1 ICLD1 or IVUL1 CARD 2C3 The third index which is 1 here is introduced to make scattering phase functions wavelength dependent in MODTRAN3 7 4 There was no wavelength dependence prior to MODTRAN3 7 15 3 CARDs 3C1 3C6 These cards are used only with the MODTRAN3 7 MODTRAN4 upgrade see Appendix A 54 16 CARD 4 REQUIRED SPECTR
5. P where cosp cos cos sin0 sin cosAg P cos g ez ye a 1 2 2 gcosp _ l g Ja cosg 1 cos Becos g h E 1 A 142 x H x 14 2xvl o Parameter A is the average single scattering albedo of the particles making up the surface parameter P g is the Henyey Greenstein asymmetry factor ranging from 1 backward scattering to 1 forward scattering parameter P Acontrols the width of the opposition effect hot spot and parameter P Sy controls the magnitude of the opposition effect Note that the atmospheric radiative transport convention for the Henyey Greenstein 61 OPTIONAL CARDs 4A 4B 1 4B2 4B3 4L1 and 4L2 variables has been adopted in these equations The BRDF community generally represents the asymmetry factor with the symbol instead of g and represents the scattering angle with the symbol g instead of q a confusing state of affairs to say the least CBRDF _ 5 or Rahman 1 2 0 0 Ap P cos cos 0 cos0 4 P P it pl vs p 1 v g cos 4 COS I gt g COS 23 L 1 G 0 0 AQ where GO 0 Ap tan 0 tan 0 2 tan tan0 cosA Parameter P po 0 characterizes the reflectance of the surface cover parameter P gis the Henyey Greenstein asymmetry factor ranging from 1 backward scattering to 1 forward scattering and parameter P k indicates the level of anisotropy of the surf
6. West of Greenwich PARM3 source sun or moon latitude PARM4 source sun or moon longitude 0 to 360 West of Greenwich PSIPO true path azimuth from H1 to H2 degrees East of true North For IPARM 1 51 Optional CARDs 3A1 and 3A2 The parameters IDAY CARD 3 and TIME must be specified This option cannot be used with ISOURC 1 which refers to the moon as the source PARMI observer latitude 90 to 90 PARM2 observer longitude 0 to 360 West of Greenwich TIME Greenwich time PSIPO true path azimuth from H1 to H2 degrees East of true North PARM3 PARM4 are not required For IPARM 2 PARMI relative azimuth angle between the observers line of sight and the observer to sun path measured from the line of sight positive east of north between 180 and 180 PARM2 the solar zenith angle at H1 the observer PARM3 PARM4 are not required Note that the calculated apparent solar zenith angle is the zenith angle at H1 of the refracted path to the sun and is less than the astronomical solar zenith angle The difference between the two angles is negligible for angles less than 80 degrees For IPARM 10 PARMI latitude at H2 PARM2 longitude at H2 0 to 360 West of Greenwich PARM3 source sun or moon latitude PARM4 source sun or moon longitude 0 to 360 West of Greenwich PSIPO true path azimuth from H2 to H1 degrees East of true North For IPARM 11 PARMI
7. ZAER22 SCALE2 ZAER31 ZAER32 SCALE3 ZAER41 ZAER42 SCALE4 If APLUS A FORMAT 3 1X F9 0 20X 3 1X F9 0 There are 12 variables in the two lines of CARD 2A as enumerated above The first set of three is for aerosol number 1 the second set of three for aerosol 2 the third set for aerosol 3 and the fourth set for aerosol 4 The meanings of the numerical values for ZAERil ZAERi2 and SCALE 1 1 2 3 and 4 are as follows ZAERil The base bottom of aerosol i ZAERi2 gt ZAERil The top of aerosol i lt ZAERil Translate original profile to new base ZAERi1 ZAERil Set values to default ignore SCALEi Also set to default when both ZAERi1 and ZAERi are blank SCALE gt 0 0 Multiply vertical profile by SCALEi 0 or blank Multiply vertical profile by 1 0 i e preserves column density The aerosols are linearly mapped into the new region and the column densities are preserved if SCALE is unity Note that since the cards are read using fixed formats blanks are interpreted as zeros By default SCALE is set to unity if blanks or 0 0 are input Note that if the APLUS option is used the two lines of CARD 2A must be present even if any of these lines are intended to consist of all blanks The MODTRAN LOWTRAN definition of an aerosol region leads to some confusion Possibly a preferred definition of the aerosol region would be the contiguous altitudes over which the aerosol 26 Optional CARD 2A concentration is
8. and parameter P4 rA is the product of z the radius of the Sun flecks on the inclined scatterers and A the scatterer area density of the canopy expressed as the scatterer surface per unit bulk area Note that the functions describing the orientation distribution of the scatterers for the illumination and viewing angles xy and Ks are defined here as twice their normal value to be consistent with the definition of multiple scattering functions H x w 63 OPTIONAL CARDs 4A 4B 1 4B2 4B3 4L1 and 4L2 CBRDF _ 12 or Ross Li pO 0 AQ R F P Ki seO 0 A9 P B B Kpr 0 0 AQ where K LSR 1 sec 8 sec 8 tan tan 0 cosAg t sin fcos t 2 1 sec 6 sec 0 1 2 P cos t min 6 0 0 Apy tano tan 0 sin Ag sai sec O sec 0 tand P tand Xx Vos Parameter P A amb is the Lambertian scattering component and equal to the bidirectional reflectance for 0 0 and 6 0 Parameter P geo is the coefficient of the LiSparse Reciprocal geometric scattering kernel Kz sp derived for a sparse ensemble of surface objects casting shadows on a Lambertian background Parameter P Kyo is the coefficient for the Ross Thick volume scattering kernel Krz so called for its assumption of a dense leaf canopy The two constants dimensionless crown relative height 2 h b and shape Ps b r parameters have been empirically obtained and should not be interpre
9. latitude at H2 PARM2 longitude at H2 0 to 360 West of Greenwich TIME Greenwich time PSIPO true path azimuth from H2 to H1 degrees East of true North For IPARM 12 PARMI relative solar azimuth degrees East of true North at H2 PARM2 solar zenith degrees at H2 Table 13 CARD 3A2 Input IPARM Options IPARM 0 1 2 10 11 12 52 PARM1 Observer Observer Azimuth Angle Latitude at H2 Latitude at H2 Relative Solar Latitude Latitude Between 90 to 90 90 to 90 Azimuth at H2 90 to 90 90 to 90 Observer LOS Degrees East amp Observer to of North Sun Path PARM2 Observer Observer Solar Zenith Longitude at Longitude at Solar Zenith at Longitude Longitude Angle H2 Degrees H2 Degrees H2 Degrees 0 to 360 0 to 360 West of West of West of West of Greenwich Greenwich Greenwich Greenwich PARM3 Source Latitude Source Latitude PARM4 Source Source Longitude Longitude TIME Greenwich Greenwich Time Time Decimal Decimal Hours Hours PSIPO True Path True Path True Path True Path Azimuth Angle Azimuth Angle Azimuth Angle Azimuth Angle from H1 to H2 from H1 to H2 from H2 to H1 from H2 to H1 Degrees East Degrees East Degrees East Degrees East of Due North of Due North of Due North of Due North ANGLEM only Lunar Phase Lunar Phase Lunar Phase Lunar Phase if ISOURC 1 Angle Angle Ang
10. 2 micron the extinction coefficients in 1 km for each altitude are listed The absorption coefficients in 1 km for each altitude are followed by the asymmetry parameters for each altitude Then the same set of information of the second wavelength 3 micron is listed This pattern continues 40 number of wavelengths and wavelengths in microns 2000 3000 ao rom ah 5500 6943 1 0600 1 5360 2 0000 2 2500 2 5000 2 7000 3 0000 343923 3 7500 4 5000 5 0000 5 5000 6 0000 6 2000 6 5000 7 2000 7 9000 8 2000 8 7000 9 0000 9 2000 10 0000 10 5910 11 0000 11 5000 12 5000 14 8000 15 0000 16 4000 17 2000 18 5000 21 3000 25 0000 30 0000 40 0000 10 number of altitudes and altitudes in m 20 9 123 6 226 3 329 1 393 8 458 6 523 4 572 0 620 7 669 3 temperature in K 287 65 286 49 285 57 284 85 285 37 285 95 285 65 287 65 288 91 288 45 pressures in mb 1010 70 999 40 988 10 976 80 969 66 962 55 955 50 949 60 943 73 937 90 RH 88 80 91 41 93 39 95 60 81 88 66 69 65 60 50 08 37 44 35 80 spectral data for 0 2 microns 156E 00 146E 00 145E 00 145E 00 144E 00 142E 00 140E 00 377E 01 377E 01 377E 01 extinction 224E 03 140E 03 133E 03 132E 03 130E 03 128E 03 125E 03 635E 06 635E 06 635E 06 absorption 801E 00 798E 00 797E 00 797E 00 797E 00 797E 00 797E 00 758E 00 758E 00 758E 00 asymmetry spectral data for 0 3 microns 150E 00 140E 00 139E 00
11. 3 Read for aerosol 3 repeat NANGLS times CARD 3C6 F 4 I J J 1 NWLF FORMAT 8 1X E9 3 Read for aerosol 4 repeat NANGLS times In this upgrade the wavelength grid and the angle grid is the same for each of the four aerosols Furthermore the phase function must be supplied either for all aerosols or no aerosol For each all CARDs 3C3 are supplied first then all CARDs 3C4 all 3CS and finally all 3C6 the CARDs for the subsequent aerosol then follow A 3 User Supplied Aerosol Profiles CARD 2C3 Prior to these upgrades the user could only input one aerosol profile by using the user selected profile option MODEL 7 IRD2 1 Now the user can have up to four user defined aerosol profiles with MODEL 7 IRD2 2 MODEL 0 is not allowed This upgrade cannot be used with the A upgrade option the APLUS option is ignored if MODEL 7 and IRD2 2 or 1 The A option allows the built in aerosols to be shifted around whereas this upgrade allows the user to input aerosol profiles up to all four with greater control The four profiles can only be input as altitude dependent aerosol extinction coefficients at 0 55 um Previously the single user defined aerosol profile could be either the altitude dependent extinction coefficient or the altitude dependent liquid water content in g m For backward compatibility the previous option for the single aerosol profile is maintained 11 Appendix A User Supplied Aerosol P
12. E Herse M and Simon P C 1996 Observation of the Solar Irradiance in the 200 350 nm Interval During the ATLAS I Mission A Comparison of Three Sets of Measurements SSBUV SOLSPEC and SUSIM Geophys Res Lett 23 2289 1996 Chance K and R J D Spurr Ring Effect Studies Rayleigh Scattering Including Molecular Parameters for Rotational Raman Scattering and the Fraunhofer Spectrum Applied Optics 36 5224 5230 1997 Clough S A F X Kneizys G P Anderson E P Shettle J H Chetwynd L W Abreu and L A Hall FASCODES3 Spectral Simulation Proceedings of the International Radiation Symposium Lenoble and Geleyn Deepak Publishing 1988 Dutton E G Climate Monitoring amp Diagnostics Laboratory NOAA private communication to Gail P Anderson 1999 Gathman S G and Davidson K L The Navy Oceanic Vertical Aerosol Model TR 1634 Naval Command Control and Ocean Surveillance Center RDT amp E Division San Diego CA 1993 Hapke B W Bidirectional reflectance spectroscopy 1 Theory J Geophys Res 86 3039 3054 1981 71 References Hapke B W Bidirectional reflectance spectroscopy 1 The extinction coefficient and opposition effect Icarus 67 264 280 1986 Justice C O E Vermote J R G Townshend R DeFries D P Roy D K Hall V V Salomonson J L Privette G Riggs A Strahler W Lucht R B Myneni Y Knjazikhin S W Running R R Nemani Z Wan A R Huete W van Lee
13. Geometry Package and Band Model Parameters for MODTRAN PL TR 93 2127 Geophysics Directorate GPOS 29 Randolph Rd Hanscom AFB MA 01731 3010 May 1993 Allen M private communication to Gail P Anderson 1990 Anderson G P and L A Hall Solar Irradiance between 2000 3100 Angstroms with Spectral Band Pass Of 1 Angstroms J Geophys Res 94D 6435 6441 1989 Berk A L S Bernstein G P Anderson P K Acharya D C Robertson J H Chetwynd and S M Adler Golden MODTRAN Cloud and Multiple Scattering Upgrades with Application to AVIRIS Remote Sens Environ 65 367 375 1998 Berk A and G P Anderson Upgrades to MODTRAN Layer Cloud Rain Models SSI TR 267 Spectral Sciences Inc 99 S Bedford Street Burlington MA 01803 1995 Berk A L S Bernstein and D C Robertson MODTRAN A Moderate Resolution Model for LOWTRAN 7 GL TR 89 0122 Geophysics Directorate Phillips Laboratory Hanscom AFB MA 01731 April 1989 ADA214337 Bernstein L S A Berk P K Acharya D C Robertson G P Anderson J H Chetwynd and L M Kimball Very Narrow Band Model Calculations of Atmospheric Fluxes and Cooling Rates Journal of Atmospheric Sciences Vol 53 No 19 pp 2887 2904 1996 Bodhaine B A N B Wood E G Dutton and J R Slusser Note on Rayleigh Optical Depth Calculations Submitted to Journal of Atmospheric and Oceanic Technology JTECH April 26 1999 Cebula R Thuillier G Vanhousier R M Hilsenrath
14. IRPT 43 CARD3 H1 H2 ANGLE RANGE BETA RO LENN PHI IfIEMSCT lt 3 CARD3 H1 H2 ANGLE IDAY RO ISOURC ANGLEM If IEMSCT 3 CARD 3A1 IPARM IPH IDAY ISOURC If IEMSCT 2 CARD 3A2 PARMI PARM2 PARM3 PARMA TIME PSIPO ANGLEM G If IEMSCT 2 CARD 3B1 NANGLS NWLF If IPH 1 CARD 3B2 ANGF D F 1 I 1 F 2 I 1 F 3 I 1 F 4 I 1 I 1 NANGLS If IPH 1 and NWLF 0 CARD 3C1 ANGF D I 1 NANGLS If IPH 1 and NWLF gt 0 CARD 3C2 WLE J 1 NWLF If IPH 1 and NWLF gt 0 CARD 3C3 FA I J J 1 NWLF If IPH 1 and NWLF gt 0 CARD 3C4 F 2 I J J 1 NWLF If IPH 1 and NWLF gt 0 CARD 3C5 FG I J J 1 NWLF If IPH 1 and NWLF gt 0 CARD 3C6 F 4 I J J 1 NWLF If IPH 1 and NWLF gt 0 CARD 4A NSURE AATEMP If SURREF BRDF or LAMBER CARD 4B1 CBRDF If SURREF BRDF CARD 4B2 NWVSRE SURFZN SURFAZ If SURREF BRDF CARD 4B3 WVSURE PARAMS D I 1 NPARAM If SURREF BRDF CARD 4L1 SALBFL If SURREF LAMBER CARD 4L2 CSALB If SURREF LAMBER CARD 5 IRPT 0 68 CARD 5 Required If IRPT 4 CARD 5 IRPT 4 CARD 4 V1 V2 DV FWHM YFLAG XFLAG DLIMIT FLAGS CARD 4A NSURF AATEMP Uf SURREF BRDF or LAMBER CARD 4B1 CBRDF If SURREF BRDF CARD 4B2 NWVSRE SURFZN SURFAZ Uf SURREF BRDF CARD 4B3 WVSURF PARAMS D 1 NPARAM If SURREF BRDF CARD 4L1 SALBFL Uf SURREF LAMBER CARD 4L
15. _F77only obj77 obj90 DATA DOCS TEST TEST COMPARE mie novam novam src and novam test 3 Create correlated x binary data files in the DATA subdirectory In DATA compile CKBIN f e g f90 CKBIN f o CKBIN exe Run CKBIN exe you will be prompted for a correlated X ASCII file name Reply with CORK15 ASC which should be placed in this directory during the untar process You will be prompted for a binary name reply with CORK15 BIN The program should announce a successful write and place the file in the DATA directory Repeat for CORKO5 ASC and CORKO1 ASC 4 Create band model parameter files Compile and run MOLBMP f Select a binary to ASCII conversion Although entering names of ASCII files is possible the files of interest should appear in the menu select 0 for B2001_01 ASC 1 for B2001_05 ASC or 2 for B2001_15 ASC Another menu permits choosing output filenames select the corresponding BIN names Once the binary files have been created the ASCII files can be deleted they can be regenerated from the binary using MOLBMP f 5 The command make f Make_F77 will generate the FORTRAN77 executable file Mod4v3rl_F77 exe while make f Make_F90 will generate the FORTRAN90 executable file Mod4v3rl_F90 exe Object files will be placed in the obj77 and obj90 directories You may need to edit the makefile to set the name and compiler parameters needed by your compiler 90 Appendix C MODTRAN Install
16. a full set 2 card images containing values for the 13 species in the order specified by Table 9 These values are required only if MDEF 2 35 Optional CARDs 2C 2C1 2C2 2C2X 2C3 For JCHAR 1 A indicates Pressure in mb B indicates Pressure in atm C indicates Pressure in torr 1 6 default to specified atmospheric MODEL value blank default to M1 CARD 1 model atmosphere value Table 8 The Association of the JCHAR J Index J 1 14 with the Variables P T and WMOL J Variable Species 1 P pressure 2 T temperature 3 WMOL 1 water vapor H20 4 WMOL 2 carbon dioxide CO2 5 WMOL 3 ozone 03 6 WMOL 4 nitrous oxide N20 7 WMOL 5 carbon monoxide CO 8 WMOL 6 methane CH4 9 WMOL 7 oxygen Oz 10 WMOL 8 nitric oxide NO 11 WMOL 9 sulfur dioxide SO2 12 WMOL 10 nitrogen dioxide NO2 13 WMOL 11 ammonia NH3 14 WMOL 12 nitric acid HNO3 Table 9 Various Names for the Heavy Molecular Gases WMOLX J J 1 13 NV o0O DU un 10 11 12 13 For JCHAR 2 CC13F CCIF CCIF CF CHCIF CrClsF3 C2Cl2F4 C2C Fs5 CIONO HNO CHC1 F CCl N205 36 F11 F12 F13 F14 F22 F113 F114 F115 CFC 11 CFC 12 CFC 13 CFC 14 CFC 22 CFC 113 CFC 114 CFC 115 Optional CARDs 2C 2C1 2C2 2C2X 2C3 A indicates ambient temperature in degrees K B indicates ambient temperature in degrees C 1 6 will default to
17. below If FLAGS 1 2 the first two characters are both blank the default slit function is used and FLAGS 3 7 are ignored Otherwise an alternative slit function is used and the results are written to pltout scn rootname psc and tape7 scn rootname 7sc FLAGS 1 1 defines the spectral units for input parameters V1 V2 DV and FWHM and output files pltout scn rootname psc and tape7 scn rootname 7sc FLAGS 1 1 blank Default spectral units in wavenumbers W Spectral units in wavenumbers M Spectral units in microns N Spectral units in nanometers FLAGS 2 2 blank Default slit function triangular lorT Triangular slit function 2orR Rectangular slit function 3orG Gaussian slit function 4orS Sinc slit function S5orC Sinc slit function 6ofH Hamming slit function 7ofU User supplied function FLAGS 3 3 blank or A FWHM is absolute R FWHM is percent relative i e FWHM 100 dv v 100 da nr FLAGS 4 4 blank Degrade only total radiance and transmittance A Degrade all radiance and transmittance components 56 CARD 4 Required FLAGS 5 5 sorS blank FLAGS 6 6 rorR blank FLAGS 7 7 torT forF blank Save non degraded results for degrading later Do not save current results Use saved results for degrading with the current slit function Do not use saved results Write a specflux or rootname flx file Use no more than 80 characters per line in spectral f
18. cloud automatically placed at the default altitude If there is a non constant rain profile below a cloud that profile is stretched or compressed depending upon whether the base altitude is increased or decreased 29 Optional CARD 2A CEXT is the cloud liquid water droplet and ice particle vertical extinction CEXT 0 Cloud water particle vertical extinction km 0 4 Do not scale extinction coefficients CEXT is defined for wavelength CWAVLN see below Within the code CEXT is used to scale the extinction and absorption coefficient curves The ratio of the input optical depth CEXT CTHIK to the calculated optical depth the product of column density and extinction coefficient at CWAVLN summed for both liquid water droplets and ice particles is determined The extinction and absorption coefficients at all frequencies are multiplied by this ratio The default cloud extinction at 0 55 um for each of the five MODTRAN liquid water droplet model clouds is listed in Table 7 NCRALT is the number of layer boundary altitudes if a user defined cloud rain profile is being input NCRALT 2 3 Number of layer boundary altitudes from CARD 2E1 in user defined cloud rain profile lt 3 Use default cloud profile for ICLD The maximum allowed value for NCRALT is 16 parameter NZCLD in this value can be increased but this change requires some modification of block data MDTA NCRALT must be at least 3 to define the cloud base th
19. is less than the astronomical solar zenith angle The difference between the two angles is small for angles less than 80 50 Optional CARDs 3A1 and 3A2 14 OPTIONAL CARDS 3A1 AND 3A2 SOLAR LUNAR SCATTERING GEOMETRY These optional input cards control the specification of the solar lunar scattering geometry when IEMSCT 2 on CARD 1 and the selection of the aerosol scattering phase function 14 1 CARD 3A1 CARD 3A1 IPARM IPH IDAY ISOURC FORMAT 415 If IEMSCT 2 IPARM 0 1 2 10 11 12 Controls the method of specifying the solar lunar geometry on CARD 3A2 IPH 0 Selects spectrally independent Henyey Greenstein aerosol phase function see CARD 3A2 1 Selects user supplied aerosol phase function see CARD 3B 2 Selects Mie generated internal database of aerosol phase functions for the MODTRAN models IDAY Day of the year from 1 to 365 used to specify the earth to sun distance and if IPARM 1 to specify the sun s location in the sky Default value is the mean earth to sun distance IDAY 93 ISOURC O Extraterrestrial source is the sun 1 Extraterrestrial source is the moon 14 2 CARD 3A2 CARD 3A2 PARM1 PARM2 PARM3 PARM4 TIME PSIPO ANGLEM G FORMAT 8F10 3 If IEMSCT 2 The definitions of PARM1 PARM2 PARM3 PARM4 are determined by the value of IPARM on CARD 3A1 see Table 13 For IPARM 0 PARMI observer latitude 90 to 90 PARM2 observer longitude O to 360
20. layer aerosol extinction coefficients is based on the water vapor content of the model atmosphere selected by MODEL ISEASN selects the seasonal dependence of the profiles for both the tropospheric 2 to 10 km and stratospheric 10 to 30 km aerosols IVULCN is used to select both the profile and extinction type for the stratospheric aerosols and to determine transition profiles through the stratosphere to 100 km VIS the meteorological range when specified will supersede the default meteorological range in the boundary layer aerosol profile set by IHAZE For repeat runs using constant pressure MODEL 0 or radiosonde input MODEL 7 or 8 and with IM set to 0 updates in the CARD2 inputs are ignored IHAZE selects the type of extinction and a default meteorological range for the boundary layer aerosol models only If VIS is also specified it will override the default IHAZE value Interpolation of the extinction coefficients based on relative humidity is performed only for the RURAL MARITIME URBAN and TROPOSPHERIC coefficients used in the boundary layer 0 to 2 km altitude The character string inputs APLUS CNOVAM and ARUSS for AeRosol User Supplied Spectra were introduced in MODTRAN3 7 to give greater flexibility in defining aerosols APLUS was introduced to modify aerosol profiles NOVAM introduced to allow selection of NOVAM and ARUSS introduced to give greater flexibility in defining aerosol optical properties APLUS Blank Defa
21. no cloud ceiling but a radiation fog or an inversion or boundary layer present decreasing extinction with height up to the height of the fog or layer Selected by ZCVSA lt 0 ZINVSA 2 0 CASE 4 no cloud ceiling or inversion layer constant extinction with height Selected by ZCVSA lt 0 and ZINVSA lt 0 ZCVSA is the cloud ceiling height km ZCVSA gt 00 sets the known cloud ceiling height 0 0 height unknown the program will calculate one for case 2 and default is 1 8 km for case 2 or lt 0 0 no cloud ceiling cases 3 and 4 ZTVSA is the thickness of the cloud case 2 or the thickness of the fog at the surface case 1 km ZTVSA gt 0 0 the known value of the cloud thickness 0 0 thickness unknown default is 0 2 km ZINVSA is the height of the inversion or boundary layer km ZINVSA gt _ 0 0 the known height of the inversion layer 0 0 height unknown default is 2 km 0 2 km for fog lt 0 0 no inversion layer case 4 if ZCVSA lt 0 0 also 33 10 OPTIONAL CARDS 2C 2C1 2C2 2C2X 2C3 USER DEFINED ATMOSPHERIC PROFILES User supplied profile data are read in when the parameter MODEL is 7 or O for a constant pressure path and IM is 1 on CARD 1 In this case CARDs 2C and 2C1 are required Using CARDs 2C 2C1 and 2C2 the user has the choice of entering gas concentration data in any of several different sets of units or defaulting to a model atmosphere concentration at the specified altitude The conc
22. required DV should not exceed FWHM for MODTRAN runs to avoid under sampling in the output spectra The recommended value for DV is FWHM 2 FWHM Slit function Full Width at Half Maximum FLAGS 1 1 is the unit specifier For the MODTRAN band model the maximum FWHM value is 50 times calculation bin size 1 5 or 15 cm The type of slit function is defined in FLAGS A minimum of twice the bin size 2 cm for the standard 1 cm bin size will insure proper sampling No convolution is performed if FWHM equals the bin size and the default slit function is selected 55 CARD 4 Required YFLAG T Transmittances are output in pltout rootname plt and pltout scn rootname psc R Radiances instead of transmittances are output in pltout rootname plt and pltout scn rootname psc XFLAG controls the units for output files pltout and pltout scn XFLAG W Spectral frequency in wavenumbers W sr cm cm or solar lunar irradiances IEMSCT 3 in W em cm M Spectral wavelength in microns line of sight radiances in W sr cm um or solar lunar irradiances IEMSCT 3 in W em7 um N Spectral wavelength in nanometers line of sight radiances in uW sr cm nm or solar lunar irradiances IEMSCT 3 in uW em nm DLIMIT Character string up to 8 characters long Used in pltout rootname plt and pltout scn rootname psc to separate output from repeat sequential MODTRAN runs FLAGS A string of seven characters each defined
23. specified atmospheric MODEL value blank default to M1 CARD 1 model atmosphere value For JCHAR 3 14 A indicates Volume mixing ratio ppmv indicates Number density molecules cm indicates Mass mixing ratio g kg B C D indicates Mass density g m E indicates Partial pressure mb F indicates Dew point temperature TD in T K H20 only G indicates Dew point temperature TD in T C H20 only H indicates Relative humidity RH in percent H20 only 1 6 will default to specified model atmosphere blank default to CARD 1 model atmosphere values M2 for H20 M3 for Oz M4 for CH4 M5 for N20 M6 for CO otherwise MDEF 10 3 CARD 2C3 CARD 2C3 AHAZE EQLWCZ RRATZ IHA1 ICLD1 IVUL1 ISEA1 ICHR FORMAT 10X 3F10 3 5I5 CARD 2C3 for user specified aerosol cloud rain models is read when IRD2 is set to 1 on CARD 2C The following instructions apply to MODTRAN3 5 as well as to more recent versions when IRD2 1 Instructions for IRD2 2 are given in Appendix A If AHAZE is positive EQLWCZ is ignored AHAZE Aerosol or cloud scaling factor equal to the visible wavelength of 0 55 um extinction coefficient km at altitude ZM EQLWCZ Equivalent liquid water content g m at altitude ZM for the aerosol cloud or fog models RRATZ Rain rate mm hr at altitude ZM 37 Optional CARDs 2C 2C1 2C2 2C2X 2C3 Only one of IHA1 ICLD1 or IVUL 1 is allowed IHA1 Aerosol model extinction and meteorological ran
24. temperature inversions modeled in NOVAM The calculation with no aerosol includes only the Rayleigh scattering component and is used as the measure of change imparted to the backscattered signature by low lying aerosols No attempt was made to smoothly incorporate these profiles into a total profile Rather the default US Standard temperature pressure and constituent primarily ozone profiles and background rural 23 km visibility aerosols were employed above 0 2 km the acceptable vertical range for the NOVAM input The spectral range presented is only that reaching the surface and near surface as wavelengths short of 300 nm will be absorbed in general at higher altitudes MODTRAN will accommodate simulations from 200 nm to the far IR including the aerosol impact so the short spectral range depicted in these calculations is not a restriction 85 Appendix B NOVAM 2000 B NO INVERSION FREE CONVECTION U o TWO INVERSION WEAK CONVECTION me s ONE INVERSION DEVELOPED BOUNDARY LYR OL 600 f A 400 200 0 00 0 02 0 04 0 06 0 08 0 10 0 12 0 14 0 16 00 200 18 ER 400 16 1000 1200 1400 D FREE CONVECTION O e TWC V WEAK CONVECTION DEVELOPED BOUNDARY LYR 280 285 290 295 300 TFMPFRATIIRF KFI VTN Figure la and b The 3 aerosol and coincident temperature profiles in extinction at 0 3um and K respectively as a function of altitude These profiles were chosen to capt
25. two particle types The default cloud water droplet column densities for the five MODTRAN liquid water clouds are listed in Table 7 CCOLIP is the ice particle IP cloud vertical column density CCOLIP 2 0 Cloud ice particle vertical column density or amount km g m lt 0 Do not scale the ice particle densities 31 Optional CARD 2A Generally CCOLIP is used to scale ice particle density the same way CCOLWD is used to scale water droplet density However two points should be noted 1 The MODTRAN cumulus and stratus type clouds ICLD 1 10 treated by this alternate CARD 2A do not contain ice particles Thus only user defined cloud profiles see CARD 2E1 below can be scaled using CCOLIP 2 If both CCOLWD and CCOLIP are zero scaling is turned off for both it does not make sense to define a cloud with no liquid water droplets or ice particles CHUMID is the relative humidity at all layer boundaries with either a positive rain rate or a positive cloud density CHUMID gt 0 amp lt 105 Cloud rain relative humidity CHUMID lt 0 Assume 100 relative humidity at cloud rain layer boundaries CHUMID gt 105 Do not alter H20 profile within the cloud As much as 5 super saturation is permitted and clouds with 0 relative humidity throughout the entire cloud region are forbidden ASYMWD is the Henyey Greenstein phase function asymmetry factor for scattering by cloud liquid water droplets IASYMWDI lt 1
26. wavelength WAVLEN D km m g If negative liquid water droplet scattering albedo minus one wat 1 at wavelength WAVLEN I If the input value for ABSC 6 I is less than 1 or if it exceeds the extinction coefficient at WAVLEN D ABSC 6 I is calculated by first determining the default absorption to extinction ratio for cloud model ICLD and then multiplying EXTC 6 I by this ratio This is equivalent to assuming that the liquid water model cloud single scatter albedo T should be used to determine the absorption coefficient A negative value for ABSC 6 I not less than 1 is taken to be the negative of the coalbedo 1 e one minus the liquid water droplet scattering albedo ASYM 6 I Liquid water droplet Henyey Greenstein scattering phase function asymmetry factor at wavelength WA VLEN I These inputs are ignored if the magnitude of the CARD 2A input ASYMWD is less than one If ASYM 6 I is also not between 1 and 1 ASYM 6 I is assigned the wavelength interpolated value from cloud model ICLD EXTC 7 I Ice particle extinction coefficient at WAVLEN I km m gl If a negative value is input EXTC 7 I is assigned the wavelength interpolated extinction coefficient from the standard cirrus cloud model ICLD 18 ABSC 7 I If positive Ice particle absorption coefficient at wavelength WAVLEN D km m g If negative Ice particle scattering albedo minus one ice 1 at wavelength WAVLEN I If the input val
27. 000 The standard and alternate forms are discussed in Subsections 8 1 and 8 2 respectively 8 1 CARD 2A Standard Form CIRRUS CLOUD MODELS ICLD 18 or 19 CARD 2A CTHIK CALT CEXT FORMAT 3F8 3 FORMAT changed in MODTRAN3 5 CTHIK is the cirrus thickness km CTHIK Use thickness statistics 0 gt 0 User defined thickness CALT is the cirrus base altitude km CALT Use calculated value 0 0 User defined base altitude vV Il CEXT is the extinction coefficient km at 0 55 micron CEXT Use 0 14 CTHIK 0 gt 0 User defined extinction coefficient 8 2 CARD 2A Alternate Form WATER ICE CLOUD MODELS ICLD 1 10 CARD 2A CTHIK CALT CEXT NCRALT NCRSPC CWAVLN CCOLWD CCOLIP CHUMID ASYMWD ASYMIP FORMAT 3F8 3 214 6F8 3 This form of CARD 2A is for modifying parameters for clouds other than cirrus Use of this CARD triggers the reading of CARDs 2E1 and 2E2 described below in their respective sections See Berk and Anderson SSI TR 267 for a more extensive discussion Default values can be assigned to any of the CARD 2A variables by setting them equal to negative nine An actual computer card image is shown below 2 leading spaces and two spaces between each number All CARD 2A variables are set to their default value with this input line 28 Optional CARD 2A 9 000 9 000 9 000 9 9 9 000 9 000 9 000 9 000 9 000 9 000 A blank line will not generate the default value
28. 139E 00 137E 00 135E 00 133E 00 283E 01 283E 01 283E 01 3717E 05 255E 05 245E 05 243E 05 240E 05 236E 05 233E 05 488E 06 488E 06 488E 06 804E 00 800E 00 799E 00 799E 00 799E 00 799E 00 799E 00 777E 00 777E 00 777E 00 83 Appendix B NOVAM B 2 Incorporation into MODTRAN First all structure variables were eliminated and all non standard system routines such as gettim were also eliminated from NOV AM Several non standard i e non FORTRAN 77 features were left intact These include the DO ENDDO structure longer than six character variable names and the use of the INCLUDE statement as these are acceptable by almost all modern compilers The goal was to minimize changes to NOVAM and to use it almost as is The changes to the NOVAM code are briefly stated later Extensive changes were made to the MODTRAN code to accommodate the way NOVAM treats its four aerosols The reason changes were extensive is that unlike MODTRAN s current requirement NOVAM does not output an aerosol profile varying with altitude and spectral extinction and absorption coefficients varying with wavelength but not with altitude Instead NOVAM outputs both altitude and spectrally varying quantities which are products of profile and spectral parameters Changes to NOVAM code itself however were kept to a minimum This meant that in order to use NOVAM in MODTRAN the user must supply the required radiosonde input data to NOVAM separa
29. 2 CSALB Uf SURREF CARD 5 IRPT 0 The final IRPT card should always be blank or contain a value of zero Table 14 summarizes the user control parameters on CARD 5 IRPT can be 1 3 or 4 which are same as 1 3 or 4 respectively with the exception that a message is printed to the screen each time a repeat run begins The user is thus able more easily to follow the progress of an extensive series of calculations Table 14 MODTRAN CARD 5 Input Parameter IRPT CARD 5 IRPT COLUMNS 1 5 Format 15 0 End of program 1 Read full set of new CARDs 2 Not used same as 0 3 Read new CARDs 3 and 5 plus optional CARDs 4 Read new CARDs 4 and 5 plus optional CARDs 69 19 DEDICATION AND ACKNOWLEDGEMENTS We dedicate this report to John Selby and the late Frank Kneizys whose pioneering work led to the development of the original LOWTRAN programs and formed the basis for the MODTRAN model MODTRAN4 is just the latest in the series of AFRL atmospheric radiative transport band models We also acknowledge the contributions of other early developers from the AF Geophysics Laboratory S A Clough L W Abreu and W O Gallery and from Spectral Sciences Inc D C Robertson Specifically for MODTRAN4 significant contributions have been made by the developers of the DISORT model K H Stamnes University of Alaska Fairbanks AK N F Larsen Raytheon ITSS Lanham MD W Wiscombe NASA Goddard Space Fligh
30. 2 km NOVAM distinguishes between three different temperature inversion cases The code was modified to output these inversion layers explicitly which are then used in MODTRAN This enables MODTRAN to use only a few layers and still accurately model the temperature effects If the aerosol does not contain inversion layers currently MODTRAN will introduce layers which are at most 100 m apart Although adequate this scheme may be improved so those layers are more closely spaced nearer to the surface where the scale height is smaller steeper and are farther apart towards the top of the boundary layer where the scale height is generally larger This may allow using fewer layers without loss of accuracy In summary NOVAM is simply used to generate a database of marine aerosol profiles and spectral information for MODTRAN NOVAM does not at present generate angular phase functions Instead it has a database of asymmetry parameters from which Henyey Greenstein phase functions can be computed In principle a Mie code can be used to generate the phase functions for NOVAM B 3 Some Results Three typical as provided in the NOVAM package profiles of aerosol extinction and coincident temperature are shown if Figures la and 1b Figure 2a b and c shows the simulated backscattered UV signatures associated with these profiles as might be measured by a potential ozone monitor staring down from a space platform These calculations use all three types of
31. 205 The 1 cm absorption cross sections are stored in DATA CFC99 01 ASC DATA CFC99_15 ASC is the 15 cm version of the file The specification of user defined profiles is modeled after the MODEL 7 option in LOWTRAN but only one unit definition see JCHARX definition in CARD 2C1 can be used for the whole set of heavy species The default profiles for these species are stored in BLOCK DATA XMLATM and are based on 1990 photochemical predictions after M Allen JPL Since some of the CFCs have increased by as 9 CARD 1 Required much as 8 per year the user might well wish to redefine these values Note that both CFC11 and CFC12 are now as much as 80 larger than the default profiles If MODEL 0 7 or 8 MODTRAN reads user supplied atmospheric profiles Set IM 1 for the first run To sequentially rerun the same atmosphere with unchanged molecular and aerosol profiles for a series of cases set IM to 0 in subsequent runs MODTRAN will then reuse the previously read data Changes made to CARD2 are ignored with IM 0 and MODEL 0 7 or 8 IM 0 For normal operation of program or when calculations are to be run with the atmosphere MODEL last read in I When user input data are to be read NOPRNT 0 For normal operation of program controls tape6 output 1 To minimize printing of transmittance or radiance table and atmospheric profiles in tape6 l Create additional tape8 output including either weighting func
32. 7 4 CARD 1A REQUIRED RADIATIVE TRANSPORT DRIVER CONT D 13 5 OPTIONAL CARDS 1A1 1A2 1A3 SPECTRAL DATA AND SENSOR RESPONSE FUNCTION FILES viii ias 16 6 CARD 2 REQUIRED MAIN AEROSOL AND CLOUD OPTIONS ossoa 19 7 OPTIONAL CARD 2A FLEXIBLE AEROSOL MODEL ccooocococconoconnioncnnncnnccnncnnccnncnnnons 26 8 OPTIONAL CARD 2A CLOUD MODELS ocoocococonnconnninonnonoonoonocanoono noo ronron non ocn ronncono nos rnorss 28 8 1 CARD 2A Standard Form CIRRUS CLOUD MODELS ICLD 18 or 19 ne 28 8 2 CARD 2A Alternate Form WATER ICE CLOUD MODELS ICLD 1 10 28 9 OPTIONAL CARD 2B ARMY VERTICAL STRUCTURE ALGORITHM eee 33 10 OPTIONAL CARDS 2C 2C1 2C2 2C2X 2C3 USER DEFINED ATMOSPHERIC PROF E S eo A a a a O a E iN 34 101 CARD 2 Conen uin er a EA onan E A E aun 34 1O Z CARDS 2 C1 2C o e e O 35 10 3 CARD 2C NA a 37 11 OPTIONAL CARDS 2D 2D1 2D2 USER DEFINED AEROSOL AND CLOUD PARAMETERS ivi a 39 SI A LE N 39 LACARRA iaa 40 11 3 CARD 2D2 lala 40 12 OPTIONAL CARDS 2E1 AND 2E2 USER DEFINED CLOUD PARAMETERS 42 121 CARD 2E iii 42 12 27 NS O eee ee gs OE 43 12 3 Alternate CARD 2E2 a O aatnas 45 13 CARD 3 REQUIRED LINE OF SIGHT GEOMETRY cee eeceeseceneceeeeeseeeeneeeaeens 47 131 Standard ARDS A A AAA ads 47 13 2 Alternate CARD 3 TRANSMITTED SOLAR LUNAR IRRADIANCE IEMSCT 3 D 14 OPTIONAL CARDS 3A1 AND 3A2 SOLAR LUNAR SCATTERING GEOMETRY 51 Te PRD BAN ie
33. 9 2000 42 60 0000 2 7000 27 10 0000 43 80 0000 3 0000 28 10 5910 44 100 0000 3 3923 29 11 0000 45 150 0000 3 7500 30 11 5000 46 200 0000 4 5000 31 12 5000 47 300 0000 5 0000 32 14 8000 In MODTRAN4 this array contains the wavelengths at which the spectral data are read in when IREG N 1 The spectral grid of built in cloud data is now much finer with 788 points The aerosol optical properties are also tabulated at the 788 grid points but the data is simply an interpolation of the lower resolution data This array is retained for backward compatibility with earlier tape5 s 41 12 OPTIONAL CARDS 2E1 AND 2E2 USER DEFINED CLOUD PARAMETERS The following inputs used with the alternate CARD 2A permit the user to control profile and spectral optical parameters for cloud models through 10 These cards cannot be used with the ICLD 18 and ICLD 19 cirrus cloud models CARD 2E1 is read if NCRALT gt 3 CARD 2E2 is read if NCRSPC 2 and a ternate CARD 2E2 is read if NCRSPC 1 on CARD 2A 12 1 CARD 2E1 CARD 2E1 ZCLD 0 CLDA 0 CLDICE L 0 RRC 0 I 1 NCRALT FORMAT 4F10 5 If ICLD 1 10 NCRALT gt 3 A series of these CARD 2E1 inputs is used to set up user defined cloud rain profiles one card per layer boundary The profile parameters being set are all arrays If the alternate CARD 2A inputs CTHIK CALT CCOLWD and CCOLIP are all assigned negative values MODTRAN calculations are performed using the user defined cl
34. AL RANGE AND RESOLUTION This card specifies the spectral range frequency wavelength increments and spectral degradation of the outputs using a slit function The default slit function which is used when FLAGS 1 2 is blank is triangular and defined on a discrete wavenumber grid Setting FLAGS 1 4 accesses a set of alternate continuous slit functions which may be defined in various frequency or wavelength units The outputs from the alternate slit functions are written to the files tape7 scn rootname 7sc and pltout scn rootname psc When an optional slit function is selected i e FLAGS 1 2 is not blank tape6 rootname tp6 tape7 rootname tp7 tape rootname tp8 and pltout rootname plt files are all generated using the finest spectral resolution parameters e g DV 1 cm and FWHM 1 cm if the 1 cm band model is selected CARD 4 V1 V2 DV FWHM YFLAG XFLAG DLIMIT FLAGS MLFLX FORMAT 4F10 0 2A1 A8 A7 13 Vi Initial frequency in wavenumber cm or alternatively wavelength in units defined via FLAGS 1 1 v2 Final frequency or wavelength DV Frequency or wavelength increment used for spectral outputs DV applies to all output files when using the default slit function 1 e FLAGS 1 4 is blank Otherwise DV is applied to tape7 scn and pltout scn and the frequency increment for the other files tape6 tape7 tape8 and pltout is set to the calculation bin size Unless only bandpass information is
35. BER CARD 5 IRPT FORMAT 15 3 CARD 1 REQUIRED MAIN RADIATION TRANSPORT DRIVER The CARD 1 format has been modified in MODTRAN4 by the replacement of the logical variable MODTRN with two new CHARACTER 1 variables MODTRN and SPEED which control the band model choice and the Correlated X options In addition the inputs TBOUND and SALB from earlier versions of MODTRAN and LOWTRAN have been replaced by TPTEMP and SURREF to accommodate the updated MODTRAN surface treatment The new format is fully backward compatible talicized features are exclusive to MODTRAN4 CARD 1 MODTRN SPEED MODEL ITYPE IEMSCT IMULT M1 M2 M3 M4 M5 M6 MDEF IM NOPRNT TPTEMP SURREF FORMAT 2A1 13 1215 F8 3 A7 MODTRN selects the band model algorithm used for the radiative transport either the moderate spectral resolution MODTRAN band model or the low spectral resolution LOWTRAN band model LOWTRAN spectroscopy is obsolete and is retained only for backward compatibility The MODTRAN band model may be selected either with or without the Correlated amp treatment MODTRN T M or blank MODTRAN band model Cor kK MODTRAN correlated k option IEMSCT radiance modes only most accurate but slower run time For L 20 cm LOWTRAN band model not recommended except for quick historic comparisons SPEED SS or blank slow speed Correlated k option using 33 absorption coefficients k values per spectral bin 1 em or 15 cm Th
36. C2X CARD 2C1 ZM P T WMOL J J 1 3 JCHAR J 1 14 JCHARX FORMAT F10 3 5E10 3 14A1 1X A1 CARD 2C2 WMOL J J 4 12 If IRD1 1 FORMAT 8E10 3 E10 3 CARD 2C2X WMOLX J J 1 13 If IRD1 1 and MDEF 2 FORMAT 8E10 3 5E10 3 ZM Altitude of layer boundary km P Pressure of layer boundary T Temperature of layer boundary WMOL 1 12 Individual molecular species densities see Table 8 for species WMOLX 1 13 Heavy molecular species densities see Table 9 for species JCHAR 1 14 Control variables for selection of units for primary profile inputs P T and molecular constituents see Table 8 JCHARX Single control variable for selection of units for entire set of CFCs and other heavy molecules See Table 9 for order and identification of these species By utilizing a choice of values for the JCHAR J control variable where J 1 14 the user can designate specific units or accept defaults for the various molecular species and for the temperature and pressure If JCHAR J is left blank the program will default to the values chosen by M1 M2 M3 M4 M5 M6 and MDEF when the given amount is zero If the amount is non zero and the JCHAR J is blank the code assumes the first option on units mb for pressure K for temperature and ppmv on constituents The single unit option JCHARX follows the same rules and for each altitude specified on CARD 2C1 the code will expect to find
37. EL SPRING SUMMER for MODEL 0 1 2 4 6 7 FALL WINTER for MODEL 3 5 1 SPRING SUMMER 2 FALL WINTER ARUSS Blank Detault USS User defined aerosol optical properties Instructions in Appendix A The parameter IVULCN Table 2 controls both the selection of the aerosol profile as well as the type of extinction for the stratospheric aerosols It also selects appropriate transition profiles above the stratosphere to 100 km Meteoric dust extinction coefficients are always used for altitudes from 30 to 100 km 20 IVULCN 0 1 BACKGROUND STRATOSPHERIC profile and extinction 2 MODERATE VOLCANIC profile and AGED VOLCANIC extinction 3 HIGH VOLCANIC profile and FRESH VOLCANIC extinction 4 HIGH VOLCANIC profile and AGED VOLCANIC extinction 5 MODERATE VOLCANIC profile and FRESH VOLCANIC extinction 6 MODERATE VOLCANIC profile and BACKGROUND STRATO SPHERIC extinction 7 HIGH VOLCANIC profile and BACKGROUND STRATOSPHERIC extinction 8 EXTREME VOLCANIC profile and FRESH VOLCANIC extinction Table 2 Shows the Value of IVULCN Corresponding to the Different Choices of Extinction Coefficient Model and the Vertical Distribution Profile VERTICAL DISTRIBUTION BACKGROUND MODERATE HIGH EXTREME z STRATOSPHERIC VOLCANIC VOLCANIC VOLCANIC A O 2 BACKGROUND ed 3 3 STRATOSPHERIC gt Z oO Z AGED E 2 4 gt VOLCANIC l FRESH VOLCANIC 5 2 g ICSTL is the air ma
38. EMSCT 3 For calculating directly transmitted solar or lunar irradiance an ITYPE 3 path is assumed and CARD 3 has the following form ALT CARD 3 H1 H2 ANGLE IDAY RO ISOURC ANGLEM FORMAT 3F10 3 I5 5X F10 3 15 F10 3 H1 Altitude of the observer H2 Tangent height of path to sun or moon ANGLE Apparent solar or lunar zenith angle at H1 IDAY Day of the year used to correct for variation in the earth to sun distance RO Radius of earth in kilometers default according to MODEL ISOURC 0 Extra terrestrial source is the sun 1 Extra terrestrial source is the moon ANGLEM Phase angle of the moon in degrees defined here as the moon centered angle between the sun and the earth required only if ISOURC 1 Enter 0 for a full moon 90 for a half moon and 180 for no moon Either H2 or ANGLE should be specified If both are given as zero then a vertical path ANGLE 0 is assumed If both are greater than zero the scheme for ITYPE 3 is invoked If IDAY is not specified then the mean earth to sun distance is assumed If the apparent solar zenith angle is not known for a particular case then the solar scattering option IEMSCT 2 may be used along with for instance the observer s location day of the year and time of day to determine the solar zenith angle see instructions for CARDs 3A1 and 3A2 Note that the apparent solar zenith angle is zenith angle at H1 of the refracted path to the sun and
39. I ABSC N D ASYM N D I 1 47 FORMAT 3 F6 2 2F7 5 F6 4 CARD 2D2 consists of 47 sets of 4 numbers 3 sets or 12 numbers per line in each aerosol region N for which IREG N is 1 See Appendix A for the meaning of IREG N gt 1 There are no corresponding CARDs 2D1 and 2D2 if IREG N 0 This card is for input of user defined aerosol or cloud extinction and absorption coefficients when IHAZE 7 or ICLD 11 VARSPC I Wavelengths for the aerosol or cloud coefficients If IREG N is 1 the wavelengths from Table 10 must be entered actually the input values are not used and the Table 10 entries are assumed For IREG N gt 1 see Appendix A EXTC N I Aerosol or cloud extinction coefficients normalized so that EXTC for a wavelength of 0 55 um is 1 0 km ABSC N I Aerosol or cloud absorption coefficient normalized so that EXTC for a wavelength of 0 55 um is 1 0 km ASYM N D Aerosol or cloud asymmetry parameter 40 Optional CARDs 2D 2D1 2D2 Table 10 VARSPC Array of Fixed Required Wavelengths for the Multiply Read CARD 2D2 Index Wavelength um Index Wavelength um Index Wavelength um SCP OIDNARWN aa a a pa DO uo Note 0 2000 17 5 5000 33 15 0000 0 3000 18 6 0000 34 16 4000 0 3371 19 6 2000 35 17 2000 0 5500 20 6 5000 36 18 5000 0 6943 21 7 2000 37 21 3000 1 0600 22 7 9000 38 25 0000 1 5360 23 8 2000 39 30 0000 2 0000 24 8 7000 40 40 0000 2 2500 25 9 0000 41 50 0000 2 5000 26
40. ICLDLG 1 END LOOP OVER NCLDWV SPECTRAL WAVELENGTHS The Alternative CARD 2E2 inputs CLDTYP and CIRTYP must each match a cloud type name CLDNAM from the CFILE data file The comparison s case sensitive but leading blanks are ignored Extensive checking is performed on the input data The spectral scattering phase functions are assumed to be normalized to unity and they are renormalized and a warning is generated if the normalization condition is not satisfied The Legendre expansion coefficients over 2N 1 are normalized such that the leading order coefficient is 1 46 13 CARD 3 REQUIRED LINE OF SIGHT GEOMETRY 13 1 Standard CARD 3 CARD 3 H1 H2 ANGLE RANGE BETA RO LENN PHI FORMAT 6F10 3 I5 5X F10 3 CARD 3 is used to define the geometrical path parameters for a given problem H1 Initial altitude km H2 Final altitude km for ITYPE 2 Tangent height km for ITYPE 3 It is important to emphasize here that in the radiance mode of program execution IEMSCT 1 or 2 H1 the initial altitude always defines the position of the observer or sensor H1 and H2 cannot be used interchangeably as in the transmittance mode ANGLE Initial zenith angle 0 to 180 degrees as measured from H1 RANGE Path length km BETA Earth center angle subtended by H1 and H2 0 to 180 degrees RO Radius of the earth km at the particular latitude of the calculation If RO is left blank the program will u
41. If SURREF BRDF CARD 4B3 defines the BRDF parameters on the input spectral grid and is repeated NWVSRF times WVSURF PARAMS BRDF spectral wavelength um The wavelength grid must be input in increasing wavelength order BRDF parameters at wavelength WVSURF The Rahman and Roujean BRDF models are 3 parameter models Ross Li is also a 3 parameter model although an additional two constants PARAMS 4 2 and PARAMS S5 1 are required as inputs See Section 17 2 for further details All other current BRDF models require 4 parameters The parameters must be entered in the order specified by the model equations of Section 17 2 i e Pi P2 65 OPTIONAL CARDs 4A 4B 1 4B2 4B3 4L1 and 4L2 17 5 CARD 4L1 CARD 4L1 SALBFL FORMAT A80 Uf SURREF LAMBER CARD 4L1 defines the name of the input data file being used to define the spectral albedo Leading blanks are ignored SALBFL Name of the spectral albedo data file The default spectral albedo file DATA spec_alb dat may be used or a user supplied file If a user supplied file is specified it must conform to the format described in the default file 17 6 CARD 4L2 CARD 4L2 CSALB FORMAT A80 If SURREF LAMBER CARD 4L2 defines the number or name associated with a spectral albedo curve from the SALBFL file As noted above input of CARD 4L2 is repeated NSURF times CSALB Number or name of a spectral albedo curve in the SALBFL file There
42. Li and A H Strahler On the derivation of kernels for kernel driven models of bidirectional reflectance J Geophys Res 100D 21 077 21 090 1995 Wanner W A H Strahler B Hu X Li C L Barker Schaaf P Lewis J P Muller and M J Barnsley Global retrieval of bidirectional reflectance and albedo over land from EOS MODIS and MISR data theory and algorithm J Geophys Res 102D 17 143 17 162 1997 Woods T N D K Prinz G J Rottman J London P C Crane R P Cebula E Hilsenrath G E Brueckner M D Andrews O R White M E VanHoosier L E Floyd L C Herring B G Knapp C K Pankratz and P A Reiser Validation of the UARS Solar Ultraviolet Irradiances Comparison with the ATLAS 1 and 2 Measurements J Geophys Res 101D 9841 9569 1996 13 APPENDIX A MODTRAN3 7 MODTRAN4 USER SUPPLIED AEROSOL UPGRADES This section contains instructions for the MODTRAN3 7 MODTRAN4 options that provide flexible wavelength dependent specification of extinction absorption and asymmetry parameters and phase functions These upgrades used in conjunction with a stand alone Mie code allow aerosols to be modeled more realistically The spectral grid can be arbitrary 1 e not limited to the default 47 fixed spectral points of Table 10 and different for each aerosol The scattering phase function can have wavelength dependence in addition to angular dependence There can be up to four user defined aerosol profiles In addition ut
43. MODTRAN4 Version 3 Revision 1 USER S MANUAL A Berk j G P Anderson P K Acharya y M L Hoke J H Chetwynd ja L S Bernstein E P Shettle M W Matthew and S M Adler Golden Spectral Sciences Inc 99 South Bedford Street 7 Burlington MA 01803 5169 lt lex O spectral com gt Air Force Research Laboratory Space Vehicles Directorate Air Force Materiel Command Hanscom AFB MA 01731 3010 lt Gail Anderson hanscom af mil gt Naval Research Laboratory Remote Sensing Division Washington DC 20375 5351 11 February 2003 A Ey AIR FORCE RESEARCH LABORATORY XZ S Vehicles Directorat CN pace venicies Directorate DAA AIR FORCE MATERIEL COMMAND 4 HANSCOM AFB MA 01731 3010 TABLE OF CONTENTS Section Page Te INTRODUCTION a e es 1 1 1 Summary of Features and Options ce eeeeseeeeeeeeceteeneeenee Error Bookmark not defined 1 1 1 Versions through MODTRAN3 5 ce eeeeeeeereeeeeeeeeeeees Error Bookmark not defined 1 12 MOD TRANS Disp a Error Bookmark not defined 1 1 3 MODTRANA iii octetos Error Bookmark not defined 1 2 Radiation Transport Upgrades ooooonoccncccocccoconocanonconcconannnonnnonos Error Bookmark not defined 2 OVERVIEW OF INPUT DATA FORMAT ada 1 2 1 Listing of CARDs and Their Format 3 2 5 10cisusccceisssecassavnsadeslescceeasdeccdasesdaceassteentsdecddananusead cs 2 3 CARD 1 REQUIRED MAIN RADIATION TRANSPORT DRIVER e cecceeeeseereeteees
44. P is either not positive or left blank MODTRAN uses the temperature of the first atmospheric level as the boundary temperature If the area average temperature AATEMP CARD 4A is not entered and the line of sight intersects the earth the temperature of the first atmospheric level is also used as the lower boundary temperature in the multiple scattering models or the first non blank character is B or b Surface spectral BRDFs Bidirectional Reflectance Distribution Functions are specified by CARD 4A 4B1 4B2 and 4B3 inputs or the first non blank character is L or l Spectral Lambertian surface s is are specified by CARD 4A 4L1 and 4L2 inputs Albedo of the earth and at H2 if TPTEMP gt 0 equal to one minus the surface emissivity and spectrally independent constant If the value exceeds one the albedo is set to 1 if SURREF is blank the albedo is set to 0 Negative integer values allow the user to access pre stored spectrally variable surface albedos from the DATA spec_alb dat file The file DATA spec_alb dat is a replacement for the DATA refbkg file used in MODTRAN3 7 and earlier versions of the model The current version contains 46 surfaces A complete list is provided in Sec 17 6 These are only meant to be representative of the types of options available the user is encouraged to add to the set or replace the existing ones Instructions for adding surfaces to the spec_alb dat file are provided
45. RAN 2 code and many of the MODTRAN3 upgrades are described in the 1996 report MODTRAN 2 3 Report and LOWTRAN 7 Model Abreu and Anderson 1996 The current documentation incorporates material from that report from Section 3 of the 1988 Users Guide to LOWTRAN 7 Kneizys ef a 1988 from the 1989 Air Force Research Laboratory AFRL report on the MODTRAN band model Berk ef al 1989 and from the 1996 Spectral Sciences Inc report on the cloud and rain model upgrades Berk and Anderson 1995 Articles Bernstein et al 1995 Berk et al 1998 discuss improvements to the band model For the most up to date information about MODTRAN please email Gail P Anderson lt Gail Anderson hanscom af mil gt Michael L Hoke Civilian AFRL VSBT lt Michael Hoke hanscom af mil gt and or Alexander Berk lt lex spectral com gt These user instructions for MODTRAN4 Version 3 Revision 1 describe each input in the MODTRAN input files tapeS or rootname tpS 2 OVERVIEW OF INPUT DATA FORMAT A MODTRAN root name input file provides the full path for MODTRAN I O The rootname file must be located in the executable directory and have the name modroot in or MODROOT IN Overview of Input Data Format If modroot in does not exist MODTRAN checks for the existence of a MODROOT IN file If neither of these files exists MODTRAN I O files are traditional ones tapeS tape6 tape7 tape8 etc Ifa root name file ex
46. RD 2C1 ZM P T WMOL 1 WMOL 2 WMOL 3 SCHAR J 1 14 JCHARX FORMAT F10 3 5E10 3 14A1 1X Al CARD 2C2 WMOL J J 4 12 FORMAT 8E10 3 E10 3 If IRD1 1 CARD 2C2X WMOLX J J 1 13 FORMAT 8E10 3 5E10 3 If MDEF 2 amp IRD1 1 CARD 2C3 AHAZE EQLWCZ RRATZ IHA1 ICLD1 IVUL1 ISEA1 ICHR FORMAT 10X 3F10 3 515 Uf IRD2 1 CARD 2D IREG N N 1 2 3 4 FORMAT 415 If IHAZE 7 or ICLD 11 CARD 2D1 AWCCON TITLE FORMAT E10 3 A70 CARD 2D2 VARSPC N D EXTC N ID ABSC N I ASYM N D I 1 2 Imax If ARUSS USS and IREG N gt 1 then Lmax IREG N Else Ina 47 FORMAT 3 F6 2 2F7 5 F6 4 CARD 2E1 ZCLD 0 CLD 0 CLDICE I 0 RR 0 I 1 NCRALT FORMAT 4F10 5 If ICLD 1 10 NCRALT gt 3 CARD 2E2 WAVLEN I EXTC 6 I ABSC 6 D ASYM 6 D EXTC 7 D ABSC 7 I ASYM 7 D I 1 NCRSPC FORMAT 7F10 5 If ICLD 1 10 NCRSPC 2 2 Alternate CARD 2E2 CFILE CLDTYP CIRTYP FORMAT A80 fICLD 1 10 NCRSPC 1 Overview of Input Data Format CARD 3 H1 H2 ANGLE RANGE BETA RO LENN PHI FORMAT 6F10 3 I5 5X F10 3 Alternate CARD 3 CARD 3Al1 CARD 3A2 CARD 3B1 CARD 3B2 CARD 3C1 CARD 3C2 H1 H2 ANGLE IDAY RO ISOURC ANGLEM FORMAT 3F10 3 I5 5X F10 3 I5 F10 3 If IEMSCT 3 IPARM IPH IDAY ISOURC FORMAT 415 If IEMSCT 2 PARM1 PARM2 PARM3 PARM4 TIME P
47. SIPO ANGLEM G FORMAT 8F10 3 If IEMSCT 2 NANGLS NWLF FORMAT 215 If IPH 1 ANGFO FC I 1 FG I 1 EG L 1 F 4 L 1 I 1 NANGLS FORMAT 8 1X F9 0 If IPH 1 and NWLF 0 ANGF 1 NANGLS FORMAT 8 1X F9 0 If IPH 1 and NWLF gt 0 WLE J J 1 NWLF FORMAT 8 1X F9 0 If IPH 1 and NWLF gt 0 In CARDs 3C3 3C6 T is angle index as in CARD 3C1 and J is the wavelength index as in CARD 3C2 CARD 3C3 CARD 3C4 CARD 3CS5 CARD 3C6 F 1 I J J 1 NWLF FORMAT 8 1X E9 3 If IPH 1 and NWLE gt 0 F 2 I J J 1 NWLF FORMAT 8 1X E9 3 If IPH 1 and NWLE gt 0 F 3 I J J 1 NWLF FORMAT 8 1X E9 3 If IPH 1 and NWLE gt 0 F 4 I J J 1 NWLF FORMAT 8 1X E9 3 If IPH 1 and NWLE gt 0 Overview of Input Data Format CARD 4 V1 V2 DV FWHM YFLAG XFLAG DLIMIT FLAGS MLFLX FORMAT 4F10 0 2A1 A8 A7 I3 CARD 4A NSURF AATEMP FORMAT 11 F9 0 if SURREF BRDF or LAMBER The set of CARD 4B1 4B2 and 4B3 inputs is repeated NSURF times CARD 4B1 CBRDF FORMAT A80 if SURREF BRDF CARD 4B2 NWVSRF SURFZN SURFAZ FORMAT if SURREF BRDF CARD 4B3 is repeated NWVSRF times CARD 4B3 WVSURF PARAMS D I 1 NPARAM FORMAT If SURREF BRDF CARD 4L1 SALBFL FORMAT A80 If SURREF LAMBER CARD 4L2 is repeated NSURF times CARD 4L2 CSALB FORMAT A80 Uf SURREF LAM
48. TA B2001_01 BIN There are also a 5 cnt and a 15 cm band model file available for faster short wave calculations DA TA B2001_05 BIN and DATA B2001_15 BIN If the 1 cm 5 cm or 15 cm band model file is selected MODTRAN will also open the corresponding 1 cni 5 cm or 15 cni Correlated k data file when input variable MODTRN CARD 1 equals C or KK The names of the CK data files are hardwired to DATA CORKO BIN DA TA CORKOS BIN and DATA CORKIS BIN CARD 1A3 FILTNM FORMAT A80 CARD 1A3 is used to select a user supplied instrument filter channel response function file It is read only if LFLTNM T in CARD 14 FILTNM User supplied instrument filter response function file name Sample A VIRIS and LANDSAT7 filter response functions are supplied with the model DA TA avirs fIt and DA TAAandsat7 fit Whenever this option is used the included file CHANNELS h should be reviewed to insure consistency between the CHANNELS h PARAMETERS and the input response function file CHANNELS h defines 4 parameters MXCHAN The maximum number of channels in the response function file MNBIN The minimum frequency bin used in the channel function integrations cm MXBIN The maximum frequency bin used in the channel function integrations cnt 2 MXNCHN The maximum number of channels to which a single band model spectral bin will contribute The CHANNELS h MNBIN and MXBIN parameters must be defined in frequency K c
49. Water droplet Henyey Greenstein scattering phase function asymmetry factor at all wavelengths 2 l Use user defined or model spectral asymmetry factors for scattering by cloud liquid water droplets Even if the spectral asymmetry factors are input using CARDs 2E2 MODTRAN uses the ASYMWD value if its absolute value is less than one ASYMIP is the Henyey Greenstein phase function asymmetry factor for scattering by cloud ice particles IAS YMIPI lt l Ice particle Henyey Greenstein scattering phase function asymmetry factor at all wavelengths 2 l Use user defined or model standard cirrus spectral asymmetry factors for scattering by cloud ice particles 32 9 OPTIONAL CARD 2B ARMY VERTICAL STRUCTURE ALGORITHM CARD 2B is the input card for the Army VSA Vertical Structure Algorithm subroutine required when IVSA 1 on CARD 2 CARD 2B ZCVSA ZTVSA ZINVSA FORMAT 3F10 3 The case is determined by the parameters VIS ZCVSA ZTVSA and ZINVSA CASE 1 cloud fog at the surface increasing extinction with height from cloud fog base to cloud fog top Selected by VIS lt 0 5 km and ZCVSA 2 0 Use case 2 or 2 below the cloud and case 1 inside it CASE 2 hazy light fog increasing extinction with height up to the cloud base Selected by 0 5 lt VIS lt 10 km ZCVSA 2 0 CASE 2 clear hazy increasing extinction with height but less so than case 2 up to the cloud base Selected by VIS gt 10 km ZCVSA 0 CASE 3
50. ace CBRDF _ 6 or Roujean p0 0 AQ R P K 8 0 AQ ES P KortO 0 AQ geo x Ag cosAg sin Ap tan tan9 G 0 0 AQp where K tan 0 tan 0 i 2m i TT 7 2 p cosp sing 7 Ker cos cos 0 4 Parameter P AL amb is the Lambertian scattering component and equal to the bidirectional reflectance for 6 0 and 0 0 Parameter P Kgeo is the coefficient of the geometric scattering kernel Kgeo and parameter P kyo is the coefficient for the Ross Thick volume scattering kernel Krz so called for its assumption of a dense leaf canopy 62 OPTIONAL CARDs 4A 4B 1 4B2 4B3 4L1 and 4L2 CBRDF _ 10 or Pinty Verstraete P14 p 0 0 A9 M cos x B 200 l K B E ET p cos 0 cos 0 n pl AQ B P Paolos ES A K B e 1 1 4 2 Abate SECAR T K X 1 Y x 1 7534Y 7 c0s0 where T 0 0 Ap x rA 1 Vx 1 2666 0 66 y v Xx vos Parameter P is the average single scattering albedo of the particles making up the surface parameter P g is the Henyey Greenstein asymmetry factor ranging from 1 backward scattering to 1 forward scattering parameter P v7 is most negative 0 4 for an erectophile canopy mostly vertical scatterers 0 for a canopy with a uniform distribution equal probability for all scatterer orientations and most positive 0 6 for a planophile canopy mostly horizontal scatterers
51. alues as a function of wavelength In this study NOVAM was modified to output this 80 Appendix B NOVAM information as a function of wavelength for a series of altitude values beginning at the lowest significant radiosonde altitude usually a few meters extending into the lower troposphere The NOVAM model is claimed to be valid up to 6 km However in consultation with Gathman private communication we have restricted the NOVAM aerosol profiles to reach no higher than 2 km The set of NOVAM routines consists of about 6000 lines of FORTRAN code written in non standard FORTRAN 77 NOVAM however needs only minimal modification so as to be acceptable to most FORTRAN compilers Extensive modification of the code was ruled out in order to maintain an easily discernible correspondence between the modified and original versions The user should familiarize herself himself with the NOVAM input files of which there are three i the Surface Observation Data File 11 the Radiosonde Profile File and 111 a file called novam in For purposes of familiarizing with NOVAM it is highly recommended that the user consult the above referenced NOVAM manual In this report only a very brief description of the inputs and output are given Questions regarding the use of NOVAM within MODTRAN should be directed to the authors of this report Note that the NOVAM code supplied with this delivery has 13 inputs in the Surface Observation File as oppos
52. ansfer calculations for inhomogeneous mixed phase clouds Phys Chem Earth B 24 237 241 1999 McElroy C T A spectroradiometer for the measurement of direct and scattered solar spectral irradiance from on board the NASA ER 2 high altitude research aircraft Geophys Res Lett 22 1361 1364 1995 McElroy C T C Midwinter D V Barton and R B Hall A Comparison of J values estimated by the composition and photodissociative flux measurement with model calculations Geophys Res Lett 22 1365 1368 1995 Pinty B and M M Verstraete Extracting Information on surface properties from bidirectional reflectance measurements J Geophys Res 96 2865 2874 1991 Rahman H B Pinty and M M Verstraete Coupled Surface Atmosphere Reflectance CSAR Model 2 Semiempirical Surface Model Usable With NOAA Advanced Very High Resolution Radiometer Data J Geophys Res 98D 20 791 20 801 1993 Rothman L S R R Gamache R H Tipping C P Rinsland M A H Smith D Chris Benner V Malathy Devi J M Flaud C Camy Peyret A Perrin A Goldman S T Massie L R Brown and R A Toth The HITRAN molecular database editions of 1991 and 1992 JOSRT 48 469 507 1992 Rothman L S C P Rinsland A Goldman S T Massie D P Edwards J M Flaud A Perrin V Dana J Y Mandin J Schroeder A McCann R R Gamache R B Wattson K Yoshino K Chance K W Jucks L R Brown V Nemtchinov and P Varanasi The HITRAN M
53. arameters This upgrade is achieved by a generalization of CARD 2C3 For this purpose AHAZE was changed from a scalar variable to an array AHAZE 4 The two versions of CARD 2C3 are shown below CARD 2C3 AHAZE 1 EQLWCZ RRATZ IHA1 ICLD1 IVUL1 ISEA1 ICHR FORMAT 10X 3F10 0 515 Uf IRD2 1 CARD 2C3 AHAZE 1 RRATZ AHAZE 2 AHAZE 3 AHAZE 4 FORMAT 10X F10 0 10X 4F10 0 If IRD2 2 The variables missing in the newer version of CARD 2C3 IRD2 2 are not needed for specifying aerosols However ICLD1 IRD2 1 allows the user to specify cloud profiles in addition to aerosol profiles with the restriction that a cloud extinction and an aerosol extinction cannot be specified at the same altitude using CARD 2C3 The price of the current upgrade is the elimination of the cloud extinction at an altitude for having the luxury of inputting up to four aerosol extinctions However user specified cloud profiles may be entered using CARD 2E1 As mentioned in lieu of extinction an aerosol profile could also be given as liquid water content in g m The conversion factor for converting liquid water content g m to extinction coefficient is given by AWCCON AWCCON can also be user specified by using CARD 2D IHAZE 7 or ICLD 11 However since in the present upgrade the aerosol profiles cannot be stated in terms of liquid water content AWCCON values in CARD 2D1 are not used A 4 Example tapeS File Here is an example o
54. are currently 46 spectral albedo curves available in the default spectral albedo file DATA spec_alb dat Leading blanks are ignored The 46 case insensitive CSALB inputs for DATA spec_alb dat are T or snow cover 2 or Torest 3 or farm 4 or desert 5 or ocean 6 or Cloud deck 7 or old grass or dead grass 9 or maple leaf 10 or burnt grass 20 or constant 0 21 or constant 5 22 or constant 50 23 or constant 80 24 or constant 30 25 or constant 10 31 or CCM3 Sea ice Kiehl et al 1996 32 or coniter JHU becknic database vegetation 33 or olive gloss paint JHU becknic database manmade 34 or deciduous tree JHU becknic database vegetation 66 or or or or or or or or or or or or or or or or or or or or or or or or or or sandy loam JHU becknic database soil granite JHU becknic database igneous rock galvanized steel JHU becknic database manmade grass JHU becknic database vegetation black plastic MWIR LWIR Aluminum MWIR LWIR Evergreen Needle Forest Mosart 14 pine forest Evergreen Broadleaf Forest Mosart 18 broadleaf pine forest Deciduous Needle Forest Mosart 18 broadleaf pine forest Deciduous Broadleaf Forest Mosart 6 broadleaf forest Mixed Forest Mosart 25 broadleaf 70 pine 30 Closed Shrubs Mosart 22 pine brush Open Shrubs Mosart 40 broadleaf b
55. ation 6 7 8 MODTRAN version 3 7 and higher has the ability to use the Navy Oceanic Vertical Aerosol Computer Model NOVAM If you need to use this code NOV AM must be compiled and run before MODTRAN producing output files for use when needed The NOVAM files are located in the novam subdirectory tree under the top MODTRAN directory Depending on need not all users will require NOVAM MODTRAN is independent of NOVAM To prepare using NOVAM go to the novam subdirectory Execute the UNIX script file createnovamexecutable which will create the NOVAM executable novam exe NOVAM novam exe reads input from novam in and writes output to novam out Three test case inputs are located in the novam test subdirectory Copy one into the novam infile name or create one and use novam exe to create novam out Copy that to NOVAM OUT upper case in the topmost MODTRAN directory which contains mod4v3rl exe for use in runs requiring NOVAM data The TEST subdirectory contains a number of input files designed to exercise wide range of MODTRAN capabilities The input files are named in the pattern tp5 copy a tp5 file into tape5 in the top level directory and then mod4v3rl exe will run that case The other way of running MODTRAN and naming I O files makes use of the file modroot in or MODROOT IN as described below Output files have tp6 tp7 tp8 7sc 7sr plt psc clr flx and chn extensions For a comparison purpose th
56. ault wind speeds are set according to the value of MODEL Table 4 For the Desert aerosol model HAZE 10 if WSS lt 0 the default wind speed is 10 m s 24 RAINRT specifies the rain rate and GNDALT specifies the altitude of the surface RAINRT Rain rate mm hr The default value is zero for no rain Used to top of cloud when cloud is present when no clouds rain rate used to 6km GNDALT Altitude of surface relative to sea level km GNDALT may be negative but may not exceed 6 km The baseline 0 to 6 km aerosol profiles are compressed or stretched based on input GNDALT GNDALT is set to the first profile altitude when radiosonde data is used model 7 Table 3 summarizes the use of the input control parameters IHAZE ISEASN IVULCN and VIS on CARD 2 Table 5 summarizes the use of the parameter ICLD 25 7 OPTIONAL CARD 2A FLEXIBLE AEROSOL MODEL CARD 2A which is read if APLUS A in CARD 2 allows the user to move MODTRAN s built in aerosols from their original positions to arbitrary altitude regions which may overlap and to compress and stretch them using only two input lines If the CARD 2 input GNDALT is non zero the aerosol densities below 6 km will undergo an additional compression or stretching as described in Section 6 An important benefit is the ability to move the tropopause height The CARD 2A options cannot be used in conjunction with NOVAM CARD 2A ZAER11 ZAER12 SCALE1 ZAER21
57. cal extinction CWAVLN 20 2 amp lt 200 0 Reference wavelength for defining cloud vertical extinction um CWAVLN outside this range specifies the default 0 55 um The variable CWAVLN is only used if a user selected value for CEXT is input Furthermore if CWAVLN is outside the spectral range of user defined cloud spectral data CARD 2E2 a fatal error message is logged and execution terminated CCOLWD is the water droplet WD cloud vertical column density CCOLWD gt 0 Cloud liquid water droplet vertical column density km g m lt 0 Do not scale the water droplet densities MODTRAN determines the ratio of this input water droplet vertical column density to the column density calculated from the input cloud base thickness and the default water droplet densities Then all the water droplet densities are scaled by this ratio so that the desired column amount results It should be noted that if the cloud being modeled only has liquid water and a positive cloud vertical extinction CEXT is input MODTRAN will change spectral extinction and absorption coefficients so that predicted path transmittances and radiances are independent of CCOLWD However if the spectral data are not being scaled to give a particular vertical extinction increasing column density will increase extinction Furthermore if the cloud consists of both liquid water droplets and ice particles CCOLWD can be used to customize the relative contribution from the
58. de are radiosonde data consisting of altitude temperature pressure and relative humidity RH and other surface observation parameters such as optical visibility wind speeds and surface IR extinction 1 km at 10 6 microns not all the inputs are required for implementation NOVAM recognizes three types of meteorological profiles characterized by existence or non existence of temperature inversions The cases are denoted numerically 1 for no inversion 2 for two inversions and 3 for one inversion The wavelength spectrum ranges from 0 2 to 40 microns The actual spectral grid in microns is 0 2 0 3 0 3371 0 55 0 6943 1 06 1 536 2 0 2 25 2 5 2 7 3 0 3 3923 3 75 4 5 5 0 5 5 6 0 6 2 6 5 7 2 7 9 8 2 8 7 9 0 9 2 10 0 10 591 11 0 11 5 12 5 14 8 15 0 16 4 17 2 18 5 21 3 25 0 30 0 40 0 The model contains four classes of marine aerosols with three mode radii of 0 03 0 24 and 2 0 microns where the mode radius is the size of the most populous part 1 e the peak of the distribution at the RH of 80 The 0 03 micron aerosol consists of two classes soluble and insoluble The other two sizes consist of soluble aerosols only The version of NOVAM from NRaD outputs surface layer altitudes and the net extinction absorption and asymmetry coefficients by combining the effect of all four aerosols The output of NOVAM consists of aerosol size distribution parameters and total extinction absorption and asymmetry v
59. ding improved accuracy with a minimal time penalty Azimuth dependence flag used with DISORT Set DISAZM to TRUE T or t to include azimuth dependence in the line of sight multiple scatter solar Since this option increases computation time DISAZM should be set to FALSE F f or blank if only vertical fluxes are needed if solar or viewing zenith angle is near vertical or if solar multiple scattering is a small radiance component e g for LWIR calculations Number of streams to be used by DISORT High NSTR values generally provide higher accuracy but slower computation times NSTR 8 is recommended with MODTRAN model aerosol and clouds although more streams are desirable if modeling highly forward peaked scatterers DISORT has been optimized for NSTR 4 8 and 16 only for further details see the DISORT documentation Stamnes ef al 1988 or the DISORT ftp site ftp climate gsfc nasa gov pub wiscombe Discr_ord Set to FALSE F f or blank to use the default solar 5 cm spectral resolution irradiances block data routine sunbd f Setto TRUE T or t to read 1 cm binned solar irradiance from a file see input LSUNEFL below this requires input of ISUN The FWHM Full Width at Half Maximum of the triangular scanning function used to smooth the TOA solar irradiance wavenumbers CO mixing ratio in ppmv The default value used when CO2MX blank or 0 is 330 ppmv the current 1999 recommended value is closer to 365
60. directly within the file It is recommended that the wavelength limits on the surface properties match or exceed the spectral range specified for the MODTRAN run MODTRAN will use the endpoint values at any wavelength outside this range no extrapolations Table 1 summarizes the use of selected CARD 1 parameters MODTRN SPEED MODEL ITYPE IEMSCT IMULT MDEF NOPRNT and SURREF 11 CARD 1 Required Table 1 MODTRAN CARD 1 Columns List Allowed Values of Input Parameters MODTRN SPEED MODEL ITYPE IEMSCT IMULT MDEF NOPRNT and SURREF CARD 1 MODTRN SPEED MODEL ITYPE IEMSCT IMULT M1 M2 M3 M4 M5 M6 MDEF IM FORMAT 2A1 13 1215 F8 3 A7 NOPRNT TPTEMP SURREF MODTRN S MODEL ITYPE IEMSCT IMULT MDEF NOPRNT SURREF COL 1 P COL 3 5 COL 6 10 COLA 11 15 COL 16 20 COL 51 55 COL 61 65 COL 74 80 E E D Tor M O User 1 Horizontal O Transmittance 0 No O For 1 tape 1 snow Defined Path Multiple MODEL 1 6 Short MODTRAN Scattering Default for Output Run Minor Species F Lor 1 Tropical 2 Slant Path 1 Thermal 1 Multiple 1 For MODEL 0 7 0 tape6 2 forest blank H1 to H2 Radiance Scattering Default for Normal Based at Minor Output LOWTRAN H1 Species Run CorK S 2 Mid 3 Slant Path 2 Thermal and Multiple 2 For 1 tapes 3 farm o Latitude to Space Solar Lunar 1 Scattering MODEL 0 7 Output Correlated K r Summer Radiance Based at User Control wit
61. e tp6 output files were created on a PC and included in TEST COMPARE directory Due to the variation in the floating number handling in various versions of compilers there might be minor differences between calculated results and those included in the COMPARE directory these difference are usually limited to the last significant digit There is a batch file to run all test cases runmt4 the file was tested for Linux system only and includes as is Alternative is to use file Batch full which also will run all test cases C 2 PC Windows Installation Steps The subdirectory pc contains an executable and binary files for a PC If you are using MODTRAN4 on a PC copy the executable to the mod4v3r1 directory and move the BIN files to the DATA directory You need not compile these files yourself There is a simple batch file included with the distribution Run_all_test bat It will run all test cases from TEST directory It creates a log txt file which includes time wall clock used for calculations of each test case File Run_all_test bat is a simple text file if you have a problem running it check that all paths are correct 91
62. e cloud top and the highest boundary altitude for which the water droplet and ice particle densities must be zero It is generally recommended that the altitude below which cloud densities are zero also be included in the cloud profile If this altitude is not entered MODTRAN assumes that the cloud densities drop to zero 1 meter below the cloud base NCRSPC is the number of wavelength entries NCRSPC IV 2 Number of spectral grid points for cloud optical data triggers CARD 2E2 1 Read auxiliary cloud spectral data file triggers alternate CARD 2E2 lt 1 Use default spectral data for ICLD If the cloud spectral data is to be included directly in the lt rootname gt tp5 input file NCRSPC must be at least 2 with minimum and maximum wavelengths that do not coincide With this option the spectral scattering phase functions are represented as Henyey Greenstein functions The maximum number of wavelengths parameter MXWVLN in PARAMS h is set to 788 in the MODTRAN 30 delivery although this value can be increase at the user discretion Tabulated cloud extinction absorption and phase function data are read from the auxiliary cloud spectral data file if NCRSPC is 1 The format of the auxiliary file is described in Section 12 3 Alternate CARD 2E2 The Parameter MXWVLN is not used with the auxiliary data file because the data are read into dynamically allocated arrays CWAVLN is the reference wavelength used in defining cloud verti
63. e cloud type maximum 80 characters DATA Macke dat Macke 2001 a sample cloud spectral data file is included in the MODTRAN delivery The Macke data is supplied provided strictly as a sample file its spectral resolution is more coarse than MODTRAN internal cloud data The cloud spectral data files can contain data for any number of cloud types The format for each cloud type is as follows Input 1 FORMAT A80 CLDNAM Water or cirrus cloud type name Input 2 FORMAT NCLDAN NCLDLG NCLDWV Number of angular grid points Number of Legendre expansion coefficients minus one Number of spectral points Input 3 FORMAT A80 INPSTR Angular grid header not used Input 4 FORMAT CLDANG ICLDAN ICLDAN 1 NCLDAN Scattering angles from 0 to 180 LOOP OVER NCLDWV INCREASING SPECTRAL WAVELENGTHS Input 5 FORMAT CLDWAV CLDEXT CLDABS Spectral wavelength um Spectral extinction cross section over average particle mass at CLDWAV km m g Spectral absorption cross section over average particle mass at CLDWAV km m g 45 Input 6 FORMAT A80 INPSTR Phase function header not used Input 7 FORMAT CLDPF ICLDAN ICLDAN 1 NCLDAN Scattering phase function as a function of angle at CLDWAV sr 1 Input 8 FORMAT A80 INPSTR Legendre expansion coefficients header not used Input 9 FORMAT CLDLEG ICLDLG ICLDLG 0 NCLDLG Legendre expansion coefficients over 2
64. ecify H1 ANGLE and RANGE c specify H1 H2 and RANGE d specify H1 H2 and BETA e specify H2 H1 PHI and LENN LENN only if H1 lt H2 f specify H2 PHI and RANGE 3 Slant Paths to Space ITYPE 3 a specify H1 and ANGLE b specify H1 and H2 for limb viewing problem where H2 is the tangent height or minimum altitude of the path trajectory c specify H2 and PHI here H1 space 48 CARD 3 Required For ITYPE 2 the following scheme is used to classify geometry inputs If PHI gt 0 and RANGE gt 0 THEN CASE 2f ELSE IF PHI gt 0 THEN CASE 2e ELSE IF BETA gt 0 THEN CASE 2d ELSE IF RANGE gt 0 AND ANGLE gt 0 THEN CASE 2b ELSE IF RANGE gt 0 THEN CASE 2c ELSE CASE 2a END IF For ITYPE 3 a similar scheme is used IF PHI gt 0 THEN CASE 3c ELSE IF H2 0 THEN CASE 3a ELSE CASE 3b END IF Table 12 lists the CARD 3 options provided to the user for the different types of atmospheric paths Table 12 Allowed Combinations of Slant Path Parameters Case LENN H1 H2 Angle Range BETA Optional PHI 2a 2b 2c 2d 2e 2f 3a 3b 3c X XX gt x x x LENN is used only when H1 gt H2 and Case 2a or H2 gt H1 and Case 2e Otherwise LENN is automatically set in the program Required Inputs 49 CARD 3 Required 13 2 Alternate CARD 3 TRANSMITTED SOLAR LUNAR IRRADIANCE I
65. ed to 9 as stated on page 9 Table 2 of the NOVAM manual These inputs are the same as stated for positions 1 to 7 The revised Table 2 is described below Values outside the stated range make the code use built in default values It is suggested that the user employ the default values when any of the specific data items are not available Sea Surface Temperature C Air Temperature C Relative Humidity Optical Visibility km Current Real Wind Speed m s Averaged Wind Speed 24 hours m s Air Mass Parameter 1 to 30 Cloud Cover Fraction 0 to 1 9 Cloud Type 0 to 9 10 Surface IR Extinction at 10 6 micron 1 km 0 001 to 100 0 11 Weather 0 to 11 12 Height of Lowest Cloud meters negative value uses default 13 Zonal Seasonal Category 1 to 6 ONDNDNB WN The Radiosonde Profile Data File is in either of the formats described on page 15 Table 4 and Table 5 of the NOVAM manual Table 4 contains data each line of which consists of an altitude 81 m potential temperature C and aerosol mixing ratio g kg The relationship between the potential temperature and the usual air temperature T is given by the formula T PYPYS K Cp C C 0 288 where the C s are heat capacities at constant pressure and constant volume Py 1013 25 mb and both temperatures are in Kelvin Potential temperature is the temperature attained by air at pressure P and temperature T where it is brought adiabatica
66. emperature AATEMP gt 0 Area averaged ground surface temperature if NSURF 2 not used if NSURF 1 Set the area averaged ground surface temperature to TPTEMP CARD 1 if the line of sight intersects the earth otherwise determine it from the atmospheric temperature profile CARDs 4B 1 4B2 and 4B3 SURREF BRDF or CARD 4L2 SURREF LAMBER are IA included for the image pixel surface first and then repeated for the area averaged ground surface if NSURF equals 2 59 OPTIONAL CARDs 4A 4B 1 4B2 4B3 4L1 and 4L2 17 2 CARD 4B1 CARD 4B1 CBRDF FORMAT A80 if SURREF BRDF Character string CBRDF defines the name of number associated with a BRDF parameterization Model names are case insensitive and leading blanks are ignored Currently there are 7 BRDF model options The symmetric Walthall Walthall 1985 and symmetric Sinusoidal Walthall are empirical models The Hapke Hapke 1981 Hapke 1986 Rahman Rahman et a 1993 Roujean Roujean etal 1992 and Ross Li Wanner et al 1995 Wanner etal 1997 Lucht et al 2000 are all semi empirical models The Pinty Verstraete Pinty and Verstraete 1991 is a physical model Generally the BRDFs are numerically integrated to define surface albedo directional hemispheric reflectivities and emissivities and azimuth moments required for interfacing to the DISORT multiple scattering routines negative values of the BRDF which can result from angular extrapo
67. entrations are entered on CARDs 2C1 and 2C2 in the units specified by JCHAR on CARD 2C1 If MDEF CARD 1 is set to 2 concentrations of the heavy molecular gases are read from CARD 2C2X in the units specified by JCHARX on CARD 2C1 Aerosol vertical distributions cloud liquid water contents and rain rates can be input at specified altitudes using CARD 2C3 The default altitudes for the four aerosol regions may be modified using the parameters IHA1 ICLD1 or IVULI1 CARDs 2C1 through 2C3 are repeated ML times where ML in CARD 2C is the number of atmospheric levels ML 1 for a horizontal path 10 1 CARD 2C CARD 2C ML IRD1 IRD2 HMODEL REE MODEL 0 7 8 IM 1 FORMAT 315 A20 F10 0 ML Number of atmospheric levels to be inserted maximum of NLAYER see PARAMS h file IRD1 Controls reading of WMOL 4 12 as described in Table 8 CARD 2C2 IRD1 0 Noread IRD1 1 Read CARD 2C2 IRD2 Controls reading AHAZE EQLWCZ CARD 2C3 IRD2 0 Noread IRD2 1 Read CARD 2C3 IRD2 2 Read new version of CARD 2C3 see Appendix A HMODEL Identification of new model atmosphere REE Earth radius in kilometers default according to MODEL This input is only read in when MODEL 8 It 1s redundant with RO on CARD 3 but the Earth radius is 34 Optional CARDs 2C 2C1 2C2 2C2X 2C3 required before CARD 3 1s read when the hydrostatic equation 1s being solved The RO input from CARD 3 is ignored when MODEL 10 2 CARDs 2C1 2C2 2
68. er supplied phase functions are read in if IPH CARD 3A2 is set to 1 Now the user supplied phase functions can vary with wavelength in addition to angle This upgrade is actually independent of the A and USS upgrades and it necessitates a generalized form of CARD 3B1 CARD 3B1 NANGLS NWLF FORMAT 2 15 If IPH 1 NWLF is the new variable which can be either O or a positive integer O means that the phase function has no wavelength dependence whereas a positive integer means that the phase function will be specified on a wavelength grid with that many points The phase function array F now has three indices aerosol index angle index and the wavelength index If NWLF 0 or blank CARD 3B2 is used as before CARD 3B2 ANGE F 1 I 1 FG I 1 FG I 1 F 4 I 1 I 1 NANGLS FORMAT 5E10 3 If IPH 1 NWLF 0 76 Appendix A User Supplied Aerosol Parameters If NWLF gt 0 CARD 3B2 is replaced by CARDs 3C1 3C6 CARD 3C1 ANGF D I 1 NANGLS FORMAT 8 1X F9 0 Read angles 0 to 180 if IPH 1 NWLF gt 0 CARD 3C2 WLEQ J 1 NWLF FORMAT 8 1X F9 0 Read wavelengths um if IPH 1 NWLF gt 0 CARD 3C3 Fd I J J 1 NWLF Read phase function for aerosol 1 if IPH 1 FORMAT 8 1X E9 3 and NWLF gt 0 repeat NANGLS times CARD 3C4 F 2 1 J J 1 NWLF FORMAT 8 1X E9 3 Read for aerosol 2 repeat NANGLS times CARD 3C5 EG L J J 1 NWLF FORMAT 8 1X E9
69. etn a ace di alesis aces teva de Gena lets ne as os 51 14 2 CARD De nnee a no e e em A aia suibs Not ES 51 15 OPTIONAL CARDS 3B1 3B2 3C1 3C6 USER DEFINED SCATTERING PHASE FUNCION St A SINO 54 CAR aol ge add gl cates a Sant Beales ok RUE etl ane oe Saeco 54 15 2 CARD SB A A id 54 15 3 CARDS BC ACG nta 54 16 CARD 4 REQUIRED SPECTRAL RANGE AND RESOLUTION 55 17 OPTIONAL CARDS 4A 4B1 4B2 4B3 4L1 AND 4L2 GROUND SURFACE CHARACTERIZATION sat Sd tc 59 A ate Ane et earnest N orate hr Cees a SE AE Peer See 59 17 2 CARD AB diia ac ii iia 60 17 3 CARD AB Zaiat 65 APR a 65 RA CARD AAA a 66 A A Case cee Neda ES E slanloa deed rand ATE 66 18 CARD 5 REQUIRED REPEAT RUN OPTION occ eceeccesecesecneeeseeeeeeeeeaeeeeeeaeenaeeaee 68 19 DEDICATION AND ACKNOWLEDGEMENTS ccceecssseeseeeseceseceseceeeseeeeesseeaecnaeeneeens 70 20 REFERENCES a Un oC APOE ROT NE ee Te aE ee 71 APPENDIX A MODTRAN3 7 MODTRAN4 USER SUPPLIED AEROSOL UPGRADES 74 A 1 User Supplied Aerosol Spectral Parameters ARUSS Option ooocooocccocononcnonnconancnannconncnns 74 A 2 User Supplied Aerosol Phase Functions CARDs 3B 1 3B2 3C1 3C6 ee eeeeeeeee 76 A 3 User Supplied Aerosol Profiles CARD 2C3 0ooocoocccocccooncconncconcnonanonn nono ncconcnnnnnrnn corn nc ns 77 A4 Exampletape El a A A inden A A A EA E EE 78 APPENDIX B NOVAM IN MODTRAN uo ecceesceseeeseceseceeeeeceseceseesaeceaecseeeaceeeeeseesaecnaeeneeees 80 Bal NOM AM Oltra 80 B 2 Incorporatio
70. f CARDs and Their Format In the following optional cards are indented nputs that are new to or have been modified for MODTRANM are in Italics CARD 1 MODTRN SPEED MODEL ITYPE IEMSCT IMULT M1 M2 M3 M4 MS M6 MDEF IM NOPRNT TPTEMP SURREF FORMAT QA1 I3 1215 F8 3 A7 CARD 1A DIS DISAZM NSTR LSUN ISUN CO2MX H2OSTR O3STR LSUNFL LBMNAM LFLTNM H20AER DATDIR SOLCON FORMAT 2L1 13 L1 14 F10 5 2A10 5 1X A1 F10 3 CARD 1A1 SUNFL2 FORMAT A80 If LSUNFL True CARD 1A2 BMNAME FORMAT A80 If LBMNAM True CARD 1A3 FILTNM FORMAT A80 If LELTNM True CARD 1A4 DATDIR FORMAT A80 If LELTNM True CARD 2 APLUS IHAZE CNOVAM ISEASN ARUSS IVULCN ICSTL ICLD IVSA VIS WSS WHH RAINRT GNDALT FORMAT A2 13 Al I4 A3 I2 315 5F10 5 CARD 2A ZAERI1 ZAER12 SCALE ZAER21 ZAER22 SCALE2 ZAER31 ZAER32 SCALE3 ZAER41 ZAER42 SCALE4 FORMAT 3 1X F9 0 20X 3 1X F9 0 If APLUS A CARD 2A CTHIK CALT CEXT FORMAT 3F8 3 I ICLD 18 or 19 Alternate CARD 2A CTHIK CALT CEXT NCRALT NCRSPC CWAVLN CCOLWD CCOLIP CHUMID ASYMWD ASYMIP FORMAT 3F8 3 214 6F8 3 Uf ICLD 1 10 Overview of Input Data Format CARD 2B ZCVSA ZTVSA ZINVSA FORMAT 3F10 3 df IVSA 1 CARD 2C ML IRD1 IRD2 HMODEL REE FORMAT 315 A20 F10 0 if MODEL 0 7 or 8 and IM 1 CARDs 2C1 2C2 2C2X and 2C3 as required are each repeated ML times CA
71. f a tape5 that has both the A and ARUSS aerosol options Notice the CARD 2A following CARD 2 which contains A as its first two characters Also note that user supplied spectral data are used for a built in aerosol profile 78 Appendix A User Supplied Aerosol Parameters A This blank line must be here or this line should have zeros 0 000e 00region 1 desert summer aerosol 43495 16743 04212 08621 10013 LTS Si 15288 18832 34675 25000 19037 17202 22352 YN 060 NY R 10 12 16 21 40 1 40 20 sI 54 50 e 00 20 90 00 59 50 40 30 00 90 1USS 0 0 0 1 0167 1 0000 1 2084 77022 81244 60842 33116 28524 82965 69210 52648 46622 48520 36801 000 2500 0 1 0 0 4 0 0 0 43495 21935 04348 05025 12218 10488 15081 12992 33903 27596 20100 17702 26897 23947 2600 0 1 0 CARD 2D 30 69 8197 7980 7689 2 9116 2 8623 3 8991 5 9065 6 8881 8 6736 9 6814 11 7023 14 6939 17 9959 20 4688 180 00000 25 00 70 21D 50 50 20 20 00 80 20 00 0 000 0 0 0 000 CARD 2A 1 0167 1 0370 1 0471 66704 78888 51168 172 30108 83153 66931 49395 46122 45705 79 8197 7666 8557 9281 8493 8706 9079 8855 6684 6748 6708 6408 5460 JO B W NR 10 11 lgs 18 SOL 0 000 34 06 s25 00 50 00 20
72. fying user defined clouds 18 Standard Cirrus model 64 um mode amp 96 um effective ice particle radius 19 Sub visual Cirrus model 4 um mode amp 6 um effective ice particle radius IVSA selects the use of the Army Vertical Structure Algorithm VSA for aerosols in the boundary layer IVSA O Not used 1 Vertical Structure Algorithm MODTRAN4 introduces a new option for input VIS Traditionally VIS specities the surface meteorological range km overriding the default value associated with the boundary layer chosen by IHAZE If set to zero VIS is the default value specified by IHAZE Visibility is related to surface aerosol extinction at 550 nm EXT350 in km by the equation 22 1n 50 VIS ko 2 EXT50 knm1 0 01159 kmi where 0 01159 kni is the surface Rayleigh Scattering Coefficient at 550nm The new option for the VIS input allows one to define the 550nm aerosol Rayleigh vertical optical depth OD The NEGATIVE of the OD is entered A new MODTRAN routine GETVIS combines the OD with ground altitude season Summer Spring or Wintet Fall and volcanic aerosol model inputs to determine the appropriate surface meteorological range Note if the input OD 1s too small 1 e less than the Rayleigh limit MODTRAN will terminate with the error message Input aerosol Rayleigh optical depth too low VIS gt 0 User specified surface meteorological range km 0 Uses the default meteo
73. ge control for the altitude ZM See IHAZE CARD 2 for options ICLD1 Cloud extinction control for the altitude ZM see ICLD CARD 2 for options When using ICLD1 it is necessary to set ICLD to the same value as the initial input of ICLD1 IVUL1 Stratospheric aerosol profile and extinction control for the altitude ZM see VULCN CARD 2 for options The precedent order of these parameters IHA1 ICLD1 and IVUL1 is as follows If IHA 1 gt 0 then others ignored If HA 1 0 and ICLD1 gt 0 then use ICLD1 If HA 1 0 and ICLD1 0 then use IVUL1 If AHAZE and EQLWCZ are both zero the default profile is loaded from IHA1 ICLD1 IVUL1 ISEA1 Aerosol season control for the altitude ZM see ISEASN CARD 2 for options ICHR Used to indicate a boundary change between 2 or more adjacent user defined aerosol or cloud regions at altitude ZM required for IHAZE 7 or ICLD 11 ICHR 0 noboundary change in user defined aerosol or cloud regions regions are not adjacent 1 signifies the boundary change in adjacent user defined aerosol or cloud regions NOTE ICHR internally defaults to 0 if HA1 4 7 or CLD1 11 38 11 OPTIONAL CARDS 2D 2D1 2D2 USER DEFINED AEROSOL AND CLOUD PARAMETERS These cards allow the user to specify the aerosol and cloud parameters extinction and absorption coefficients and asymmetry parameter for any or all four of the aerosol altitude regions They are only read if IHAZE 7 o
74. h M H2 of Heavy MODTRAN Molecules 3 Mid 3 Transmitted 2 tape8 4 desert Latitude Solar Lunar Plus Winter Irradiance Spectral Cooling Rates 4 Sub Arctic 5 ocean Summer 5 Sub Arctic 6 cloud Winter deck 6 1976 U S 7 old grass Standard 7 User See Sec 17 6 Defined for list M1 M2 M3 M4 M5 M6 MDEF IM TPTEMP and SURREF are left blank for standard cases Options for non standard models CO gt Oo NO SO NO NH3 HNO CFC s plus CIONO NHO CCl and N Os stands for slow and M stands for medium speed of execution of the code 12 4 CARD 1A REQUIRED RADIATIVE TRANSPORT DRIVER CONT D CARD 1A inputs enable selection of scattering options scaling of molecular profiles customizing of the top of atmosphere TOA solar irradiance and specification of data files CARD 1A DIS DISAZM NSTR LSUN ISUN CO2MX A20STR O3STR LSUNFL LBMNAM LFLTNM H20AER SOLCON FORMAT 2L1 13 L1 14 F10 5 2A10 4 1X A1 2X F10 3 DIS s forblank Used only if IMULT 1 in CARD 1 Set DIS to T or t to DISAZM f or blank NSTR 2 4 8or 16 LSUN t for blank ISUN CO2MX activate the DISORT discrete ordinate multiple scattering algorithm If DIS is F f or blank the less accurate but faster Isaac s two stream algorithm 1s used If DIS is set to S or s DISORT calculations are performed at a few fixed wavelengths and used to Scale Isaac s results provi
75. ic 8 Extreme Fresh volcanic volcanic 23 CARD 2 Required 0 to 2 km 2 to 10 km 10 to 30 km 30 to 100 km Default VIS can be overridden by VIS gt 0 on CARD 2 Sets own default VIS Table 4 Default Wind Speeds for Different Model Atmospheres Used with the Navy Maritime Model IHAZE 3 WSS and WHH Model Model Atmosphere Default Wind Speed m s 0 User defined Horizontal Path 6 9 1 Tropical 4 1 2 Mid latitude summer 4 1 3 Mid latitude winter 10 29 4 Sub arctic summer 6 69 5 Sub arctic winter 12 35 6 U S Standard EZ 7 User defined 6 9 Table 5 MODTRAN CARD 2 Input Parameter ICLD ICLD o Da Eh UY NO NO 10 11 18 19 Cloud and or Rain Option NO CLOUDS OR RAIN CUMULUS CLOUD ALTOSTRATUS CLOUD STRATUS CLOUD STRATUS STRATOCUMULUS NIMBOSTRATUS CLOUD 2 0 MM HR DRIZZLE MODELED WITH CLOUD 3 2 0 MM HR LIGHT RAIN MODELED WITH CLOUD 5 12 5 MM HR MODERATE RAIN MODELED WITH CLOUD 5 25 0 MM HR HEAVY RAIN MODELED WITH CLOUD 1 75 0 MM HR EXTREME RAIN MODELED WITH CLOUD 1 USER DEFINED CLOUD EXTINCTION AND ABSORPTION STANDARD CIRRUS MODEL SUB VISUAL CIRRUS MODEL WHH specifies the 24 hour average wind speed for use with the Navy maritime model WHH 24 hour average wind speed m s Used with the Navy Aerosol Maritime NAM model IHAZE 3 For the Navy Aerosol Maritime model if WSS WHH 0 def
76. ility programs are provided which allow MODTRAN to be run with the Navy Oceanic Vertical Aerosol Model NOVAM A 1 User Supplied Aerosol Spectral Parameters ARUSS Option Previous to this upgrade the user could provide extinction absorption and asymmetry parameters only for user supplied aerosol profiles IHAZE 7 or ICLD 11 which are in fact the extinction values at 0 55 um Furthermore the spectral parameters were limited to the 47 wavelengths of Table 10 This was done using CARDs 2D 2D1 and 2D2 with IHAZE 7 or ICLD 11 There have been two generalizations to user supplied aerosol spectral data e Now the user can supply spectral data on an arbitrary grid for IHAZE 7 or ICLD 11 For this ARUSS in CARD 2 needs to be set to the three character string USS Additionally the meaning of the IREG N N 1 2 3 and 4 variables in CARD 2D has been generalized when gt 1 they now specify the number of wavelengths at which data is supplied e The user can also supply spectral data for the default aerosol profiles as selected by THAZE ISEASN and IVULCN IHAZE 7 and ICLD 11 instead of relying on the sparse built in databases of MODTRAN Setting ARUSS to the character string USS also does this The USS option can also be used in conjunction with the APLUS option The relevant CARDs for these upgrades are CARD 2D 2D1 and 2D2 as described below Note that the extinction and absorption coefficients in MODTRAN are dimension
77. io 2 ety pa a Van A 57 Sinc Sinc x sin 1x 17x Fs 6 s Sinds 6 6 12061 Sinc F 5 sSine s 5 6 s 0 88589 Hamming F 6 0 230822 8 2 33235 Sinc s S 8 Sinc s 8 8 1 Sinc s 5 6 1 0 88589 A 58 17 OPTIONAL CARDS 4A 4B1 4B2 4B3 4L1 AND 4L2 GROUND SURFACE CHARACTERIZATION These optional input cards control the specification of the ground surface reflectance and emittance when the first non blank character in SURREF CARD 1 is B or L case insensitive 17 1 CARD 4A CARD 4A NSURF AATEMP Uf SURREF BRDF or LAMBER FORMAT 11 F9 0 CARD 4A inputs permit the modeling of adjacency effects by providing an option to decouple reflectance properties of the image pixel H2 surface and the ground surface used in the multiple scattering models As an example this option allows one to model observations of a ground calibration tarp placed within a uniform background NSURF 1 Use the reflectance properties of the image pixel for the area averaged ground surface in the multiple scattering models If the line of sight intersects the earth the area averaged surface temperature 1s set to TPTEMP CARD 1 otherwise this temperature is determined from the atmospheric temperature profile 2 Define reflectance properties for the area averaged ground surface that are independent of those of the image pixel Also specify an area averaged ground surface t
78. is option ts recommended for upper altitude gt 40 km cooling rate and weighting function calculations only M medium speed Correlated k option 17 k values CARD 1 Required MODEL selects one of the six geographical seasonal model atmospheres or specifies that user defined meteorological or radiosonde data are to be used MODEL 0 If single altitude meteorological data are specified constant pressure horizontal path only see instructions for CARDs 2C 2C1 2C2 2C2X and 2C3 Tropical Atmosphere 15 North Latitude Mid Latitude Summer 45 North Latitude Mid Latitude Winter 45 North Latitude Sub Arctic Summer 60 North Latitude Sub Arctic Winter 60 North Latitude 1976 US Standard Atmosphere y Du FF Ww NY If a user specified model atmosphere e g radiosonde data is to be read in See instructions for CARDs 2C 2C1 2C2 2C2X and 2C3 for further details Pressure dependent atmospheric profiles A user specified model atmosphere e g radiosonde data is to be read in with altitudes determined from the pressure profile by solving the hydrostatic equation See instructions for IM on CARD 1 and for CARDs 2C 2C1 2C2 2C2X and 2C3 for further details ITYPE indicates the type of atmospheric line of sight LOS path ITYPE 1 Horizontal constant pressure path i e single layer no refraction calculation 2 Vertical or slant path between two altitudes 3 Vertical or slant path to space or g
79. ists and its very first line contains a non null string this string is treated as a prefix The root name should contain no embedded blanks leading and trailing blanks are ignored The modroot in character string is used as a prefix for the I O files whose names have mnemonic suffixes As an example if the string is casel the MODTRAN I O files will have these names casel tpS Primary input file tape5 casel tp6 Primary output file tape6 casel tp7 Spectral plotting output file tape7 casel tp8 Auxiliary spectral data output file tape8 casel 7sc casel tp7 convolved with scanning function tape7 scn casel 7sr Scratch file tape7 scr casel plt Two column spectral data output file pltout casel psc casel plt convolved with scanning function pltout scn casel clr Spectral cooling rate data output file clrates casel chn Spectral data convolved with channel response functions channels out casel flx Spectral diffuse and direct flux values at each atmospheric level specflux MODTRAN is controlled by a single input file tapeS or rootname tp5 which consists of a sequence of six or more CARDS inputs lines The input file format is summarized below Except when specifying file names character inputs are case insensitive Also blanks are read as zeroes for numerical inputs and as default values otherwise Detailed descriptions of the card formats and parameters are given in the following sections 2 1 Listing o
80. iversity Press 1986 89 APPENDIX C MODTRAN INSTALLATION AND I O FILES This file outlines the steps required to obtain install and execute MODTRAN on a UNIX system It also mentions a new input output I O file structure for MODTRAN Therefore this file should be read even if one has already installed the code or is familiar with the installation process This file is duplicated as the README file in the MODTRAN distribution tar file The top level directory for MODTRAN is Mod4v3r1 The 4v3r1 refers to MODTRANG4 version 3 and revision 1 Please contact either Gail Anderson lt Gail Anderson hanscom af mil gt or Michael L Hoke Civilian AFRL VSBT lt Michael Hoke hanscom af mil gt for questions regarding distribution status or installation Technical questions may be addressed to either Gail Anderson or Alexander Berk lt lex O spectral com gt C 1 UNIX Installation Steps 1 Contact Gail P Anderson lt Gail Anderson O hanscom af mil gt or Michael L Hoke Civilian AFRL VSBT lt Michael Hoke hanscom af mil gt to obtain the code 2 Unzip the file gunzip Mod4v3rl tar gz will produce the tar file Mod4v3rl tar The uncompress command will also work Then untar the file tar xvf Mod4v3r1 tar this will build a MODTRAN directory structure Mod4v3rl beneath the directory in which Mod4v3rl tar is located The top level directory Mod4v3rl contains these subdirectories src src
81. kely close to 1 is used as a scale factor for the TOA Top Of Atmosphere solar irradiance The built in data files in the DATA directory integrate to 1368 00 W m for newkur dat 1362 12 W m for cebchkur dat 1359 75 W m for chkur dat and 1376 73 W m for thkur dat An additional scaling of the solar irradiance value to account for earth to sun distance based on day of year CARD 3A1 is applied within MODTRAN and this earth to sun correction factor is written to tape6 or rootname tp6 Do not scale the TOA solar irradiance The solar constant is assigned the input value W m As with SOLCON lt 0 an additional scaling of the solar irradiance value to account for earth to sun distance based on day of year CARD 3A1 is applied within MODTRAN and this earth to sun correction factor is written to tape6 or rootname tp6 15 5 OPTIONAL CARDS 1A1 1A2 1A3 1A4 SPECTRAL DATA AND SENSOR RESPONSE FUNCTION FILES CARD IAI SUNFL2 FORMAT A80 CARD 1A1 is used to select the TOA solar irradiance database It is read only if LSUNFL T in CARD IA SUNFL2 lor blank The corrected Kurucz database is used DAT A newkur dat ae The Chance database is used DATA chkur dat 3 The Cebula plus Chance data are used DATA cebchkur dat 4 The Thuillier plus corrected Kurucz are used DATA thkur dat afilename A user defined database residing in the file The solar databases are obtained from various sources Anderso
82. lation of the measurement based parameterizations are replaced by 0 For the simple empirical models an option to use analytic representations of the reflectance quantities is also provided The model descriptions below are primarily intended just to define the BRDF parameters expected by MODTRAN the user should consult the original references for further details CBRDF _ or Walthall P G 0 A9 R PB0 0 cos Ap ROO P O 0 where O is the view zenith angle from the surface to the sensor H1 0 1s the source zenith angle at the surface and Ag isthe view to source relative azimuth angle from the surface CBRDF _ 51 or Walthall a Analytically evaluated Walthall reflectance integrals 60 OPTIONAL CARDs 4A 4B1 4B2 4B3 4L1 and 4L2 CBRDF 11 or Sine Walthall p 0 0 Ap P P sind sind cos Ag Psin 0 sin 0 BP sin sin 6 The sinusoidal Walthall form was introduced to facilitate Monte Carlo sampling of photon trajectories The sinusoidal Walthall parameters can be approximated from the Walthall parameters by equating zenith integrations term by term This lead to the following relationships B P Pi 9n 7P 64 Ps 7 4 D P Pres r 742 DP CBRDF _ 52 or Sine Walthall a Analytically evaluated sinusoidal Walthall reflectance integrals CBRDF_ _ 4 or Hapke p o 0 AQ E 1 EE Pi COS p P H cos R H cos6 P 1 cosO c0s0 B cos P
83. le Angle G Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry Asymmetry only if IPH 0 Parameter Parameter Parameter Parameter Parameter Parameter 1 to 1 1 to 1 1 to 1 1 to 1 1 to 1 1 to 1 for use with for use with for use with for use with for use with for use with Henyey Henyey Henyey Henyey Henyey Henyey Greenstein Greenstein Greenstein Greenstein Greenstein Greenstein Phase Function Phase Function Phase Function Phase Function Phase Function Phase Function The remaining control parameters are TIME PSIPO ANGLEM Greenwich time in decimal hours that is 8 45 a m is 8 75 5 20 p m is 17 33 etc used with IPARM 1 or 11 Path azimuth degrees East of true North that is due north is 0 0 due east is 90 0 etc used with IPARM 0 1 10 or 11 Phase angle of the moon in degrees defined here as the moon centered angle between the sun and the earth required only if ISOURC 1 Enter 0 for a full moon 90 for a half moon and 180 for no moon Asymmetry factor for use with Henyey Greenstein phase function only used with IPH 0 1 for complete forward scattering O for isotropic or symmetric scattering and 1 for complete back scattering 53 15 OPTIONAL CARDS 3B1 3B2 3C1 3C6 USER DEFINED SCATTERING PHASE FUNCTIONS These input cards are for entering user defined phase functions when IPH 1 CARD 3A1 The following instructions apply when the ARUSS
84. less because they are defined by dividing the actual values by the extinction at 0 55 um Kaps A ABS A EXT 0 55 um 74 Appendix A User Supplied Aerosol Parameters CARD 2D IREG 1 IREG 2 IREG 3 IREG 4 FORMAT 415 If IHAZE 7 or ICLD 11 or ARUSS USS CARD 2D1 AWCCON TITLE FORMAT E10 3 18A4 CARDs 2D1 and 2D2 needed if IREG 1 gt 0 CARD 2D2 VARSPC 1 I EXTC 1 D ABSC 1 D ASYM 1 D 1 IREG 1 or 47 FORMAT 3 F6 2 2F7 5 F6 4 If ARUSS is not set CARD 2D1 AWCCON TITLE FORMAT E10 3 18A4 If IREG 2 gt 0 CARD 2D2 VARSPC 2 I EXTC I ABSC 2 I ASYMQ D 1 IREG 2 or 47 FORMAT 3 F6 2 2F7 5 F6 4 If ARUSS is not set CARD 2D1 AWCCON TITLE FORMAT E10 3 18A4 If IREG 3 gt 0 CARD 2D2 VARSPC 3 I EXTC 3 I ABSC 3 I ASYM 3 D I 1 IREG 3 or 47 FORMAT 3 F6 2 2F7 5 F6 4 If ARUSS is not set CARD 2D1 AWCCON TITLE FORMAT E10 3 18A4 If IREG 4 gt 0 CARD 2D2 VARSPC 4 I EXTC 4 D ABSC 4 I ASYM A4 D I 1 IREG 4 or 47 FORMAT 3 F6 2 2F7 5 F6 4 If ARUSS is not set CARDs 2D1 and 2D2 are repeated up to four times one pair for each aerosol However the two cards for aerosol i are needed if and only if IREG N gt 0 The only differences between the present and prior forms are in CARD 2D and CARD 2D2 Now CARD 2D has four integer values denoting the number of spectral grid points for each of the four aerosols IREG N
85. lly 1 e at constant entropy to a standard pressure P Houghton 1986 Table 5 contains data each line of which consists of a line number an integer log base 10 of pressure in millibars multiplied by 10 the air temperature in C RH in percent and pressure in millibars multiplied by 10 As stated above one needs the profile data either in the format of Table 4 and Table 5 Table 4 is said to be in n format whereas Table 5 is said to be in r format presuming that n denotes number defined by mixing ratio while r denotes relative humidity In addition to these files NOVAM needs another file called novam in An example of novam in is reproduced below 1905sops 1905prof txt n Here 1905sops is the Surface Observation File and 1905prof txt is the Profile File in the n format as indicated by the last line This file then specifies for the program where the necessary data files can be found 82 The output of NOV AM novam out now in a form suitable for MODTRAN typically looks as follows The sta icized text will not appear in the output The first number is 40 which is the number of wavelengths in microns which are then individually listed The number 10 is the number of altitudes in meters which are then individually listed Then the temperatures in K for each altitude are listed followed by the pressures in MB and relative humidity RH in Then for the first wavelength 0
86. lux table i e include line feeds for each spectral point These files can be quite large unless input MLFLX see below is used to limit the number of atmospheric levels altitudes The output data is spectrally gridded based on the input DV CARD 4 value This option is unavailable with the LOWTRAN band model MODEL L or F on CARD 1 Write a specflux or rootname flx file For each spectral point all flux values are on a single line i e there are no line feeds A warning is warranted here Some FORTRAN compilers limit the number of characters per line and setting FLAGS 7 7 to FALSE can cause this limit to be exceeded This option is not available with the LOWTRAN band model MODEL L or F on CARD 1 Do not write a spectral flux table MLFLX Number of atmospheric levels for which spectral fluxes FLAGS 7 7 T or F are output starting from the ground The Top Of Atmosphere value is also output If MLFLX is left blank or set to 0 spectral flux values are output at all atmospheric levels The scanning slit functions as chosen by FLAGS 2 2 are defined below All built in scanning functions are symmetrical about the unit is specified by FLAGS 1 1 central spectral wavelength 6 A or frequency o Vo the Let A be the FWHM along the frequency axis Triangular F fe 6 8 lt A 0 elsewhere ze A A Square A Fa 0 6 lt a 0 elsewhere Gaussian p
87. n and Hall 1989 Cebula ef al 1996 Chance and Spurr 1997 Kurucz 1993 Kurucz 1995 McElroy 1995 McElroy et al 1995 Thuillier ef al 1997 Thuillier et al 1998 Woods ef al 1996 The user defined file must be in a special form The first line must contain a pair of integers The first integer designates the spectral unit 1 for frequency in wavenumbers cm 2 for wavelength in nanometers nm and 3 for wavelength in microns um The second integer denotes the irradiance unit 1 for Watts em em 2 for photons sec em nm and 3 for Watts m um or equivalently milli watts m nm The subsequent lines contain one pair of frequency and irradiance entry per line There is no restriction on frequency or wavelength increments However data beyond 50 000 wavenumbers are ignored If needed data in the user supplied file are padded with numbers from newkur dat so that the data encompasses the range of 50 to 50 000 wavenumbers Note that the user defined file has a form that 1s different from DATA cebchkur dat DATA thkur dat DA TA newkur dat and DA TA chkur dat 16 Optional CARDs IAI 142 1A3 CARD 142 BMNAME FORMAT A80 CARD 1A2 is used to select the name of the binary direct access version of the band model parameter data file It 1s read only if LBMNAM T in CARD IA BMNAME Name of binary direct access version of the band model parameter data file The default name for the 1 cm band model file is DA
88. n into MODTRAN ui a 84 B3 Somo Residir 85 B 4 NOVAM input and MODTRAN input Files ooooonnncnnnnaninccconanannnonncnonononn nono nono ncnonccnnnnnnnnos 88 B 5 Future Upgrades to NOVAM Implementation oooconncnnnnnnnonononnnnnnncnannnnn nono ncnoncnnnncnnn ccoo cnn 88 111 B 6 Modifications to NOVAM to Code 0 ceccesccccsssescenseccetsceconseccenseccenseesontescenteccenseesontenes 89 BATRES IG BEG RE E BEE es 89 APPENDIX C MODTRAN INSTALLATION AND I O FILES 1 0 0 eee eceeecetecseeeneeneeeneeeeeees 90 CSN SWC a on Tadeo Error Bookmark not defined C2 Uni Installation Steps ii A a ae ee 90 AA oe a A A aded Error Bookmark not defined LIST OF TABLES Table 1 MODTRAN CARD 1 Columns List Allowed Values of Input Parameters MODTRN SPEED MODEL ITYPE IEMSCT IMULT MDEF NOPRNT and SURREF 12 Table 2 Shows the Value of IVULCN Corresponding to the Different Choices of Extinction Coefficient Model and the Vertical Distribution Profile 21 Table 3 MODTRAN CARD 2 Input Parameter ICLD 24 Table 4 Default Aerosol Region Boundaries 27 Table 5 Properties of the MODTRAN Cumulus and Stratus Type Model Clouds 29 Table 6 The Association of the JCHAR J Index J 1 14 with the Variables P T and WMOL 36 Table 7 Various Names for the Heavy Molecular Gases WMOLX J J 1 13 36 Table 8 VARSPC Array of Fixed Required Wavelengths for the Multiply Read CARD 2D2 41 Table 9 Default Values of the Earth Radius for Differen
89. nr units even though the filter function file data may be entered in frequency or wavelength nm or microns units If the filter function file is used it must be in the following form UNITS_HEADER 17 HEADER 1 Wi T11 W12 T12 W13 T13 HEADER 2 W21 T21 W22 T22 W23 T23 etc Here UNITS_HEADER is a string whose first character is N for nm W for wavenumbers or M for microns denoting the wavelength or frequency unit HEADER is a string whose first character is non numeric and not a decimal point denotes the start of a list of wavelength response pairs for the channel Wij Tij are the a wavelength and response values for the 1 channel CARD 144 DATDIR FORMAT A80 CARD 144 contains DATDIR the path name for the MODTRAN data files If a molecular band model data file name is explicitly entered DA TDIR s used for that file DATDIR Path name for the directory containing MODTRAN data files 18 6 CARD 2 REQUIRED MAIN AEROSOL AND CLOUD OPTIONS CARD 2 APLUS IHAZE CNOVAM ISEASN ARUSS IVULCN ICSTL ICLD IVSA VIS WSS WHH RAINRT GNDALT FORMAT A2 13 Al I4 A3 I2 315 5F10 5 IHAZE ISEASN IVULCN and VIS select the altitude and seasonal dependent aerosol profiles and aerosol extinction coefficients HAZE specifies the aerosol model used for the boundary layer 0 to 2 km and a default surface meteorological range The relative humidity dependence of the boundary
90. olecular 72 Spectroscopic Database and HAWKS HITRAN Atmospheric Workstation 1996 Edition JQSRT 60 665 710 1998 Roujean J L M Leroy P Y Dechamps A Bidirectional Reflectance Model of the Earth s Surface for the Correction of Remote Sensing Data J Geophys Res 97D 20 455 20 468 1992 Snell H E J L Moncet G P Anderson J H Chetwynd S Miller and J Wang FASCODE for the Environment FASE Proceedings of Atmospheric Propagation and Remote Sensing IV SPIE 2471 pp 88 95 1995 Stamnes K S C Tsay W Wiscombe and K Jayaweera Numerically Stable Algorithm for Discrete Ordinate Method Radiative Transfer in Multiple Scattering and Emitting Layered Media Applied Optics 27 2502 2509 1988 Thuillier G Herse M Simon P C Labs D Mandel H and Gillotay D 1996 Observation of the UV Solar Spectral Irradiance Between 200 and 350 nm During the ATLAS I Mission by the SOLSPEC Spectrometer Sol Phys 171 283 302 1997 Thuillier G M Herse P C Simon D Labs H Mandel and D Gillotay 1996 Observation of the Visible Solar Spectral Irradiance Between 350 and 850 nm During the ATLAS I Mission by the SOLSPEC Spectrometer Sol Phys 177 41 61 1998 Walthall C L J M Norman J M Welles G Campbell and B L Blad Simple equation to approximate the bidirectional reflectance from vegetative canopies and bare soil surfaces Applied Optics 24 383 387 1985 Wanner W X
91. oud rain profiles exactly as input However the CARD 2A variables can be used to study the effect of changing the input cloud s thickness altitude or column amounts ZCLD I 0 Altitude above ground level of layer boundary I for the user defined cloud rain profile KM ZCLD 1 0 can be 0 and this is necessary if it is raining on the ground The model also allows the cloud to actually sit on the ground The ZCLD must monotonically increase Also a fatal error will result if the highest cloud altitude ZCLD NCRALT 0 is above the top of the MODTRAN atmosphere 100 km above sea level for the model atmospheres CLD I 0 Liquid water droplet density at altitude ZCLD I 0 g m The liquid water droplet densities cannot be negative MODTRAN models the densities as varying linearly between altitudes The entire CLD array is scaled if the CARD 2A variable CCOLWD is assigned a non negative value CLDICEd 0 Ice particle density at altitude ZELDA 0 g m 42 Optional CARDs 2E1 and 2E2 The ice particle densities cannot be negative MODTRAN models the densities as varying linearly between altitudes The entire CLDICE array is scaled if the CARD 2A variable CCOLIP is assigned a non negative value RR 0 Rain rate at altitude ZCLD 0 mm hr The rain rates can not be negative Ifa rain rate is entered through CARD 2 variable RAINRT that constant rain rate supersedes this parameter Thus if a user defined rain rate profile is de
92. positive By this definition the region of aerosol 1 for example is from 0 to 3 km the profile linearly decreases from a positive value at 2 km to zero at 3 km Instead in previous MODTRAN documentation this region is said to be from 0 2 km In the MODTRAN upgrade the ZAERi1 and ZAERi values refer to the bounding altitudes which sandwich the entire region where the aerosol concentration is positive Table 6 lists the default values of these bounding altitudes along with the commonly referred to region boundaries for each aerosol One caveat with regard to the CARD 2 inputs should be noted For the Tropospheric aerosol model IHAZE 6 MODTRAN combines the boundary layer Aerosol 1 and tropospheric Aerosol 2 regions therefore these region may not be scaled independently Thus the parameters used to scale the tropospheric aerosol model are min ZAER11 ZAER21 max ZAER12 ZAER22 and max SCALE1 SCALE2 Table 6 Default Aerosol Region Boundaries Aerosol Common Region Definition Actual ZAERil Actual ZAERi2 1 0 2 km 0 km 3 km 2 2 10 2 11 3 10 30 10 35 4 30 100 30 100 27 8 OPTIONAL CARD 2A CLOUD MODELS CARD 2A is required for all cloud models ICLD gt 0 except ICLD 11 Note that the original MODTRAN3 0 format has been changed To run a default cloud case with ICLD 1 10 the alternative CARD 2A should read 9 000 9 000 9 000 9 9 9 000 9 000 9 000 9 000 9 000 9
93. ppmv Dutton 1999 13 CARD IA Required H2OSTR O3STR LSUNFL LBMNAM LFLTNM H2OAER t f or blank t f or blank t f or blank t f or blank Vertical water vapor column character string If blank or 0 the default water vapor column is used If the first non blank character is g the water vapor column in g cm follows g e g g 2 0 If the first non blank character is an a the water column in ATM cm follows a e g a 3000 Otherwise a positive value is interpreted as a scaling factor for the water column e g 2 0 doubles the default water vapor column H2OSTR should not be used with a constant pressure path i e MODEL 0 on CARD 1 The water density within water clouds ICLD 1 10 is not scaled unless CHUMID on CARD2A exceeds 105 Also the water number density at each profile altitude will not be increased above 100 RH relative humidity or by more than 5 times the original value When the 100 RH limit is reached the water is distributed to other levels to the extent possible to achieve the input water column There is an option to ignore the 100 relative humidity limit This option is invoked by setting the first non blank character in H20STR to a plus sign Thus if one wants to set the water column to 3 0 g cnr without the 100 RH limit set H2OSTR to g3 0 Vertical ozone column character string If blank or 0 the default ozone column is used If the firs
94. r ICLD 11 are specified on CARD 2 THE FOLLOWING INSTRUCTIONS ONL Y APPL Y WHEN PARAMETER ARUSS CARD 2 IS NOT SET TO USS WHEN ARUSS EQUALS USS SEE APPENDIX A FOR INSTRUCTIONS 11 1 CARD 2D CARD 2D IREG N N 1 4 If IHAZE 7 or ICLD 11 FORMAT 415 IREG specifies in which of the four altitude regions a user defined aerosol or cloud model is used IHAZE 7 ICLD 11 It controls the number of pairs of CARDs 2D1 and 2D2 read in 1 pair for each region for which IREG N 1 The region boundary altitudes default to 0 2 3 10 11 30 35 100 km but can be overridden with THA1 CARD 2C3 with MODEL 7 See Section 7 for a more complete description of the default aerosol regions IREG N 0 Use default values for the region N N 1 2 3 and 4 1 Read extinction absorption and asymmetry parameter for the region 39 Optional CARDs 2D 2D1 2D2 11 2 CARD 2D1 CARD 2D1 and CARD 2D2 are read sequentially once for each of the four aerosol regions for which IREG N 1 CARD 2D1 AWCCON TITLE FORMAT E10 3 18A4 AWCCON isa conversion factor from extinction coefficient km to equivalent liquid water content g m It is numerically equal to the equivalent liquid water content corresponding to an extinction coefficient of 1 0 km at a wavelength of 0 55 um AWCCON has units of km g m TITLE for an aerosol or cloud region up to 72 characters 11 3 CARD 2D2 CARD 2D2 VARSPC I EXTC N
95. re also not available In consultation with S Gathman they can be generated for the NOVAM aerosols and incorporated in MODTRAN 4 The output of the Mie code can be put in a format so that user can include them in the MODTRAN input file without extensive editing 5 Based on the El Chichon and Mt Pinatubo eruptions the content size type and H gt SO4 component of fresh and aging volcanic aerosols need to be altered from the default profiles now available within MODTRAN E P Shettle private communication 88 Appendix B NOVAM 6 MODTRAN currently merges NOVAM generated profiles e g extinction and temperature into those describing the rest of the atmospheric profile from whatever source has been specified default or user defined This could lead to very coarse discontinuities whose impact might need to be explored General validation against real radiosonde data will provide additional confidence in the procedure B 6 Modifications to NOVAM to Code As mentioned NOVAM modifications were kept to a bare minimum Here is a list of types of coding changes to NOVAM 1 All structure variables were replaced using this scheme structure member was replaced by structure_member This of course meant that numerous corresponding changes to subroutine arguments had to be made 2 The driver3 f routine was substantially changed to output the novam out file described earlier 3 The assyml routine in the file optics2 f was s
96. rological range set by IHAZE See Table 3 VIS lt 0 Negative of the vertical aerosol plus Rayleigh optical depth WSS specifies the current wind speed for use with the Navy maritime and desert aerosol models WSS Current wind speed m s Used with the Navy Aerosol Maritime NAM model IHAZE 3 or the DESERT model IHAZE 10 Table 3 MODTRAN CARD 2 Input Parameters IHAZE ISEASN IVULCN and VIS CARD 2 APLUS IHAZE CNOVAM ISEASN ARUSS IVULCN ICSTL ICLD IVSA VIS WSS WHH RAINRT GNDALT FORMAT A2 I3 Al 14 A3 I2 315 5F10 5 IHAZE ISEASN IVULCN In y In In coL VS extinction COL SEASON COL SEASON PROFILE EXTINCTION RO KM EXTINCTION 3 5 7 10 14 15 0 No Aerosols fa e a RURAL Spri Spri Meteoric 2 5 1 pring pring dust Summer summer ate extinction 3 ve Navy 2 Fall Fall maritime winter winter LOWTRAN 0 Background Background Normal i 4 23 oe 7 atmospheric maritime A 1 stratospheric stratospheric Tropospheric profile profile Moderate Aged 2 z URBAN tropospheric 2 volcanic volcanic extinction 6 50 Tropospheric 3 High iaa volcanic volcanic 7 23 User defined 4 Hist Aged volcanic volcanic ot Transition 8 02 Fog 1 5 Moderate Fresh profiles volcanic volcanic volcanic to normal 9 05 Fog 2 6 Moderate Background volcanic stratospheric 10 Desert 7 High Background volcanic stratospher
97. round IEMSCT determines the mode of execution of the program IEMSCT O Program executes in spectral transmittance mode 1 Program executes in spectral thermal radiance no sun moon mode 2 Program executes in spectral thermal plus solar lunar radiance mode if IMULT 0 only single scatter solar radiance is included 3 Program calculates directly transmitted spectral solar lunar irradiance IMULT determines inclusion of multiple scattering MS IMULT O Program executes without multiple scattering Program executes with multiple scattering IEMSCT must equal 1 or 2 to execute with multiple scattering MS contributions are calculated using plane parallel geometry the solar illumination on each layer is determined with spherical refractive geometry important for low sun angles when the ISAACS MS model is selected CARD 1A If MULT 1 the solar geometry at the location of H1 latitude and longitude is used in the CARD 1 Required MS calculation if IMULT 1 the MS calculation is instead referenced to H2 The quantity H2 is the final path altitude unless ITYPE 3 and H2 gt 0 in that case the MS plane parallel atmosphere is defined near the tangent point of the limb path The path zenith of 90 atthe tangent point is a forbidden input to the plane parallel MS models because it leads to a mathematical singularity For simulation of sensors on satellite platforms IMULT should generally be set to 1 since MS will onl
98. rush Woody Savanna Mosart 20 soil grass scrub Savanna Mosart 19 grass scrub Grassland Mosart 13 meadow grass Wetland Mosart 51 wetland Cropland Mosart 45 crop Urban Mosart 21 urban commercial Crop Mosaic Mosart 46 mixed vegetation Antarctic Snow Mosart 9 old snow 1000 micron radius Barren Desert Mosart 28 mixture of material rock amp silt sand Ocean Water Mosart 1 water Tundra Mosart 16 tundra Fresh Snow Mosart 43 fresh snow 50 micron radius Sea Ice Mosart 10 sea ice 3 meters thick 67 18 CARD 5 REQUIRED REPEAT RUN OPTION CARD 5 IRPT FORMAT 15 Non zero values of the control parameter IRPT cause MODTRAN to repeat program execution so that a series of problems can be run with a single submission of tape5 A message is written to standard output indicating a repeat run 1s beginning if a negative value of IRPT ts input IRPT Oor blank STOP program Read full set of new data cards followed by an additional CARD 5 3 Read new line of sight and solar lunar geometry CARD 3 CARD 3A and surface CARD 4A inputs followed by an additional CARD 5 4 Read new spectral and surface CARD 4 inputs followed by an additional CARD 5 The previous calculation atmospheric profiles are reused when the IRPT 3 or IRPT 4 options are selected In these cases the specific sequences of CARD inputs are as follows If IRPT 3 CARD5
99. s In fact setting all CARD 2A inputs to zero would produce an isotropic scattering ground level cloud CTHIK is the cloud vertical thickness CTHIK Cloud vertical thickness km gt 0 lt 0 Use default cloud thickness The cloud vertical thickness is defined as the altitude difference between the highest and lowest cloud profile boundary altitude for which either water droplet or ice particle density is positive The ten MODTRAN cloud rain models are derived from five distinct clouds The default thicknesses for these clouds are listed in Table 7 This will not only scale default clouds but also user specified cloud profiles CARD 2E1 Table 7 Properties of the MODTRAN Cumulus and Stratus Type Model Clouds Thickness Base 55um Ext Column Amt ICLD Cloud Type km km km km g m 1 Cumulus 2 34 0 66 92 6 1 6640 2 Altostratus 0 60 2 40 128 1 0 3450 3 Stratus 0 67 0 33 56 9 0 2010 4 Stratus Stratocumulus 1 34 0 66 38 7 0 2165 5 Nimbostratus 0 50 0 16 92 0 0 3460 CALT is the cloud base altitude relative to ground level CALT gt 0 Cloud base altitude relative to ground level km lt 0 Use default cloud base altitude This differs from the meaning of CALT in the cirrus cloud models ICLD 18 or 19 which define base altitude relative to sea level Note that a value of zero translates the cloud down to the ground the user must enter a negative altitude to have the
100. se the mid latitude value of 6371 23 km if MODEL is set equal to 7 Otherwise the earth radius for the appropriate standard model atmosphere specified by MODEL will be used as shown in Table 11 LENN switch to determine short and long paths for cases 2a and 2e as described below If LENN 1 path will be long extending through the tangent height If LENN 0 default path will be short PHI zenith angle 0 to 180 degrees as measured from H2 target or final altitude towards H1 sensor or initial altitude 47 CARD 3 Required Table 11 Default Values of the Earth Radius for Different Model Atmospheres Model Model Atmosphere Earth Radius RO km 0 User defined Horizontal Path Not used 1 Tropical 6378 39 2 Mid latitude summer 6371 23 3 Mid latitude winter 6371 23 4 Sub arctic summer 6356 91 5 Sub arctic winter 6356 91 6 U S Standard 6371 23 7 User defined 6371 23 It is not necessary to specify every variable on CARD 3 only those that adequately describe the problem according to the parameter ITYPE as described below also see Table 12 1 Horizontal Paths ITYPE 1 a specify H1 RANGE b If non standard meteorological data are to be used that is if MODEL 0 on CARD 1 then refer to the instructions for CARD 2C for a detailed explanation 2 Slant Paths Between Two Arbitrary Altitudes ITYPE 2 a specify H1 H2 ANGLE and LENN LENN only if H2 lt H1 b sp
101. sired variable RAINRT must not be positive 12 2 CARD 2E2 CARD 2E2 WAVLEN D EXTC 6 I ABSC 6 D ASYM 6 D EXTC 7 D ABSC 7 I ASYM 7 D I 1 NCRSPC FORMAT 7F10 5 If ICLD 1 10 NCRSPC 2 2 The CARD 2E2 variables are used to input user defined cloud spectral data arrays If the CARD 2A inputs CEXT ASYMWD and ASYMIP all specify the use of defaults MODTRAN uses these spectral data exactly as input However if a positive vertical cloud extinction CEXT is input the extinction and absorption coefficients curves are scaled Similarly if the CARD 2A asymmetry factors ASYMWD and ASYMIP have magnitude less than one they supersede the ASYM 6 I and ASYM 7 I values respectively WAVLEN I Wavelength um I in the spectral grid The first wavelength WAVLEN 1 can be as low as 0 0 um and the wavelengths must be entered in increasing order If a positive vertical cloud extinction CEXT is input on CARD 2A the reference wavelength CWAVLN or 0 55 um must be between WAVLEN 1 and WAVLEN NCRSPC inclusive or else MODTRAN execution will be terminated with an error message EXTC 6 I Liquid water droplet extinction coefficient at wavelength WAVLEN km m g If a negative value is input EXTC 6 I is assigned the wavelength interpolated extinction coefficient from the default data for cloud model ICLD 43 Optional CARDs 2E1 and 2E2 ABSC 6 I If positive liquid water droplet absorption coefficient at
102. ss character 1 to 10 used with the precursor to NOVAM i e the Navy maritime Aerosol Model NAM IHAZE 3 Default value is 3 ICSTL is not used with NOVAM ICSTL 1 Open ocean 10 Strong continental influence ICLD specifies the cloud and rain models used The rain profiles decrease linearly from the ground to the top of the associated cloud model The program cuts off the rain at the cloud top 21 CARD 2 Required ICLD 0 No clouds or rain dl Cumulus cloud layer base 0 66 km top 3 0 km 2 Altostratus cloud layer base 2 4 km top 3 0 km 3 Stratus cloud layer base 0 33 km top 1 0 km 4 Stratus stratocumulus layer base 0 66 km top 2 0 km 5 Nimbostratus cloud layer base 0 16 km top 0 66 km 6 2 0 mm hr ground Drizzle Modeled with cloud 3 and 0 86 mm hr at 1 0 km 7 5 0 mm hr ground Light rain Modeled with cloud 5 and 2 6 mm hr at 0 66 km 8 12 5 mm hr ground Moderate rain Modeled with cloud 5 and 6 0 mm hr at 0 66 km 9 25 0 mm hr ground Heavy rain Modeled with cloud 1 and 0 2 mm hr at 3 0 km 10 75 0 mm hr ground Extreme rain Modeled with cloud 1 and 1 0 mm hr at 3 0 km 11 Read in user defined cloud extinction and absorption Triggers reading CARDs 2D 2D1 and 2D2 for up to 4 altitude regions of user defined extinction absorption and asymmetry parameters This option is kept for backward compatibility CARD 2A inputs afford greater flexibility in speci
103. t Center Greenbelt MD and S C Tsay NASA Goddard Space Flight Center Greenbelt MD J Qi Michigan State University East Lansing MI C B Schaaf Boston University Boston MA and N Goldstein Spectral Sciences Inc Burlington MA provided assistance and direction in the development of the MODTRAN4 BRDF model H Dothe Spectral Sciences Inc Burlington MA helped develop the 15 cm MODTRAN band model and data file Contributions to earlier versions of the MODTRAN model include the 2 stream multiple scattering algorithm R G Isaacs and R D Worsham Atmospheric and Environmental Research Inc Cambridge MA and the Navy Oceanic Vertical Aerosol Model NOVAM led by S G Gathman Space and Naval Warfare Center SPAWAR Modifications to the solar irradiance options were suggested by R Kurucz and K Chance Smithsonian Observatory Harvard University M E VanHoosier Naval Research Laboratory A Hall AFRL and G Thuillier Service d Aeronomie du CNRS France among others K Minschwaner New Mexico State Technical College provided suggestions for an enhanced integration for the single scattered radiance implementation This work was funded by AFRL under contracts F19628 91 C 0145 and F19628 98 0050 70 20 REFERENCES Abreu L W and G P Anderson The MODTRAN 2 3 Report and LOWTRAN 7 Model Prepared by Ontar Corporation for PL GPOS 1996 Acharya P K D C Robertson and A Berk Upgraded Line of Sight
104. t Model Atmospheres 48 Table 10 Allowed Combinations of Slant Path Parameters 49 Table 11 CARD 3A2 Options for Different Choices of IPARM 52 Table 12 MODTRAN CARD 5 Input Parameter IRPT 69 iv 1 INTRODUCTION MODTRAN Berk ef al 1989 Berk ef al 1998 has served as the U S Air Force USAF standard moderate spectral resolution radiative transport model for wavelengths extending from the thermal InfraRed IR through the visible and into the ultraviolet 0 2 to 10 000 0 um The spectroscopy of MODTRAN4 Version 3 Revision 1 Mod4v3r1 is based on HITRAN2K line compilation Rothman et al 1992 Rothman et al 1998 with update through 2001 The MODTRAN 1 cm statistical band model was developed collaboratively by Spectral Sciences Inc and the USAF Research Laboratory and it provides a fast alternative 100 fold increase in speed to the USAF first principles and more accurate line by line LBL radiative transport models FASCODE Clough 1988 and FASCODE for the Environment FASE Snell ef al 1995 Comparisons between MODTRAN and FASE spectral transmittances and radiances show agreement to within a few percent or better in the thermal IR MODTRAN4 includes flux and atmosphere scattered solar calculations essential components in analysis of near IR and visible spectral region data that are not readily generated by LBL models Technical descriptions of the MODTRAN approach are available from a variety of sources The original MODT
105. t non blank character is g the ozone column in g cm follows g e g g 0 0001 If the first non blank character is an a the ozone column in ATM cm follows a e g a 0 2 Otherwise a positive value is interpreted as a scaling factor for the ozone column e g 2 0 doubles the default ozone column One Dobson unit equals 10 ATM cm at 273 15 K O3STR should not be used with a constant pressure path i e MODEL 0 on CARD 1 If TRUE T or t read solar radiance data file name from CARD 1A1 The file is only used if LSUN is also TRUE If LSUNFL is FALSE F f or blank and LSUN is TRUE the file name DATA newkur dat is used LSUNFL can also be set to 1 2 3 or 4 see CARD 1A1 If TRUE T or t read band model parameter data file name from CARD 1A2 Otherwise the default 1 cm bin band model database DATA B2001_01 BIN is used If TRUE T or t read file name for user defined instrument filter function from CARD 1A3 If t aerosol optical properties are modified to reflect the changes from the original relative humidity profile arising from the scaling of the water column see H2OSTR on this CARD Otherwise the H20 properties are fixed even though water amount has changed 14 LDATDR t f or blank SOLCON lt 0 0 or blank gt 0 If TRUE T or t the directory name of the MODTRAN data files is read in otherwise data files are assumed to be in directory DATA The absolute value of SOLCON li
106. te from the MODTRAN inputs NOVAM is executed off line and creates a file called novam out lower case in UNIX which is used as input to MODTRAN uppercase filename in UNIX Note that NOVAM input files are currently separate and in addition to MODTRAN s usual input file which is named tape5 If the altitudes in tapeS overlap with those in the NOVAM output file the meteorological parameters such as humidity pressure and temperature used by MODTRAN will be those provided by NOVAM In a future upgrade the requirement for NOVAM to have a separate input file can be eliminated both MODTRAN and NOVAM will then use the information contained in the MODTRAN input file tapeS This process will be facilitated by the prior development of a radiosonde compression scheme SSI and PL GPO have collaborated to write a program called SNDTP5 which can compress radiosonde measurements consisting of hundreds of altitude layers such as those used by NOVAM into a form more suitable for the finite layering appropriate and generally just as accurate for transmittance and radiance calculations fora MODTRAN tapeS As mentioned NOVAM actually can model altitudes as high as 6000 meters However in consultation with E P Shettle Naval Research Laboratory private communication and S G Gathman NOSC private communication the maximum NOVAM altitude relevant for MODTRAN 84 was determined to be 2 km In reality for most applications it will be less than
107. ted too literally The LiSparse Reciprocal kernel has only been validated for h b 2 and b r 1 These are the recommended constant input values for parameters P and Ps and the values that will be used to invert the angular radiance data from NASA s Moderate Resolution Imaging Spectroradiometer MODIS Justice ef a 1998 64 OPTIONAL CARDs 4A 4B 1 4B2 4B3 4L1 and 4L2 17 3 CARD 4B2 CARD 4B2 NWVSRE SURFZN SURFAZ FORMAT If SURREF BRDF CARD 4B2 defines the number of BRDF spectral grid points and the direction of the surface normal Currently the surface normal is required to point upward the surface normal inputs are included in anticipation of a future upgrade allowing modeling of a graded ground surface and or arbitrarily oriented image facets NWVSRF SURFZN SURFAZ 17 4 CARD 4B3 CARD 4B3 Number of BRDF spectral grid points If NWVSRF is set to 1 the BRDF will be spectrally independent The maximum allowed value for NWVSRF is defined by the parameter MWVSRF in the PARAMS h file If necessary the user can increase MWVSRF and then recompile MODTRAN Upon delivery of MODTRAN MWVSRF is set to 50 The zenith angle degrees of the surface normal Currently only a value of 0 is supported The true azimuth angle of the image pixel surface normal 0 for North 90 for East 180 for South and 270 for East This value is currently not used WVSURF PARAMS D I 1 NPARAM FORMAT
108. tions in transmission mode IEMSCT 0 or fluxes in radiation modes with multiple scattering on MULT 1 and IEMSCT 1 or 2 2 Generates spectral cooling rate data in addition to the tape8 output spectral cooling rates are written to the clrates or rootname clr file If NOPRNT is set to 1 for multiple scattering calculations spectral diffuse and total flux values along the lines of sight will be written to tape8 These values are 1 cm spectral resolution results 15 cm results if the 15 cm band model data file is used Spectral flux values convolved with the instrument slit function are output to the specflux or rootname flx file if FLAGS 7 7 is not left blank CARD 4 Be warned that setting NOPRNT to 1 for long paths e g ground to space over a large spectral range e g 0 4 to 0 7 um will generate large tapes files 10 CARD 1 Required TPTEMP gt 0 lA SURREF BRDF IV LAMBER 0 or blank Boundary temperature K of image pixel 1 e at H2 used in the radiation mode if IEMSCT 1 or 2 for slant paths that intersect the earth OR terminate at a gray boundary for example cloud target If the area average temperature AATEMP CARD 4A is not entered and the line of sight intersects the earth TPTEMP is also used as the lower boundary temperature in the multiple scattering models No surface emission if H2 is above ground If the path intersects the Earth and TPTEM
109. ubstantially rewritten to fix an interpolation problem with the asymmetry parameters 4 The calls to gettim were eliminated as it is not available on all machines 5 potential_temperature was replaced by potential_temp as this variable and routine name is too long 6 The file drivesub2 f was renamed drivesb2 f so that the new prefix has no more than eight characters which is the maximum for the PC environment 7 As before the sigfile is created by calling it with repeatflag equal to false In the same call a new file called invfile is created with inversion and other extra layers to be used as MODTRAN layers This file also contains pressure air temperature not potential temperature and RH It is created by modifying the routine make_rdataary Later the driver with repeatflag true reads the invfile and creates the novam out file at these altitudes 8 The driver checks to see that all altitudes in the infvile that are greater than 2 km are discarded Also discarded is the set of all top altitudes if the first altitude in the set has a relative humidity which is below 50 That is because the NOVAM aerosols appear to be restricted to be in an environment of 50 humidity or higher B 7 References Gathman S G and Davidson K L The Navy Oceanic Vertical Aerosol Model TR 1634 Naval Command Control and Ocean Surveillance Center RDT amp E Division San Diego CA 1993 Houghton J T The Physics of Atmospheres Cambridge Un
110. ue for ABSC 7 I is less than 1 or if it exceeds the extinction coefficient at WAVLEN D ABSC 7 D is calculated by first determining the default absorption to extinction ratio for the standard cirrus cloud model ICLD 18 and then multiplying EXTC 7 I by this ratio This is equivalent to assuming that the standard cirrus cloud model single scatter albedo T should be used to determine the absorption coefficient A negative value for ABSC 7 I not less than 1 is taken to be the negative of the coalbedo i e one minus the ice particle scattering albedo ASYM 7 I Ice particle Henyey Greenstein scattering phase function asymmetry factor at wavelength WAVLEN I 44 Optional CARDs 2El and 2E2 These inputs are ignored if the magnitude of the CARD 2A input ASYMIP is less than one If ASYM 7 D is also not between 1 and 1 ASYM 7 I is assigned the wavelength interpolated value from the standard cirrus cloud model ICLD 18 12 3 Alternate CARD 2E2 Alternate CARD 2E2 CFILE CLDTYP CIRTYP FORMAT A80 If ICLD 1 10 NCRSPC 1 Alternate CARD 2E2 contains 3 lines and is used to enter the name of auxiliary cloud spectral data file and a pair of cloud types Nominally the first cloud is a water cloud and the second is a cirrus cloud however one can assign any cloud type each of the pair CFILE Cloud spectral data full path file name maximum 80 characters CLDTYP Water cloud type maximum 80 characters CIRTYP Ic
111. ult A Use Aerosol Plus option triggers reading of CARD 2A to characterize user defined aerosols optical properties 19 CARD 2 Required IHAZE 1 No aerosol attenuation but the model clouds may be included i e ICLD 1 2 10 0 No aerosol or cloud attenuation included in the calculation 1 RURAL extinction default VIS 23 km 2 RURAL extinction default VIS 5 km 3 NAVY MARITIME extinction sets VIS based on wind speed and relative humidity 4 MARITIME extinction default VIS 23 km LOWTRAN model 5 URBAN extinction default VIS 5 km 6 TROPOSPHERIC extinction default VIS 50 km 7 User defined aerosol extinction coefficients Triggers reading CARDs 2D 2D1 and 2D2 for up to 4 altitude regions of user defined extinction absorption and asymmetry parameters This option is kept for backward compatibility the ARUSS USS option affords greater flexibility in specifying user defined aerosols 8 FOG1 Advective Fog extinction 0 2 km VIS 9 FOG2 Radiative Fog extinction 0 5 km VIS 10 DESERT extinction sets visibility from wind speed WSS CNOVAM Blank Default N Navy Oceanic Vertical Aerosol Model NOVAM Appendix B ISEASN selects the appropriate seasonal aerosol profile for the tropospheric and stratospheric aerosols Only the tropospheric aerosol extinction coefficients are used with the 2 to 10 km profiles ISEASN 0 Season determined by the value of MOD
112. ure the number of temperature inversions used as a parameter in NOV AM 1 or no inversion 2 or two inversions and 3 for 1 inversion There was not attempt to find the most perturbing case so these can be considered typical Note the MODTRAN merges these profiles into those describing the rest of the atmospheric profile from whatever source has been specified default or user defined This can lead to very coarse discontinuities whose impact might need to be further explored 86 Appendix B NOVAM ROSOIL NO ANCE NOVAM DIFFER INVERSION NO AEROSOL NOVAM TWO DIFFERANCE INVERSION 0 325 0 350 0 375 O 40 WAVELENGTH um ROSOL NOVAM ONE DIFFERANCE INVERSION es Bs 0O 40C moor rr 375 nr 0 325 0 350 O WAVELENGTH um Figure 2a b c As denoted these represent typical sensitivity to the new NOV AM aerosol profiles shown in Figure 1 The plots are shown linearly to emphasize the impact at the longer wavelengths that see to the surface and therefore would be impacted by boundary layer variability At shorter wavelengths lt 0 3 um the stratospheric aerosol component might be important under extremes of volcanic loading That sensitivity requires a logarithmic plot and has not been explored in this study 87 Appendix B NOVAM B 4 NOVAM input and MODTRAN input Files The NOVAM files were described earlier So they are not reproduced here In the delivered
113. uwen R E Wolfe L Giglio J P Muller P Lewis and M J Barnsley The Moderate Resolution Imaging Spectroradiometer MODIS Land remote sensing for global change research IEEE Trans Geosci Remote Sens 36 1228 1249 1998 Kiehl J T ef al Description of the NCAR Community Climate Model CCM3 NCAR Tech Note NCAR TN 420 STR Natl Cent for Atmos Res Boulder Colo 1996 Kneizys F X E P Shettle L W Abreu J H Chetwynd G P Anderson W O Gallery J E A Selby and S A Clough Users Guide to LOWTRAN 7 AFGL TR 88 0177 Geophysics Directorate GPOS 29 Randolph Rd Hanscom AFB MA 01731 3010 August 1988 ADA206773 Kurucz R L 1 Atomic and Molecular Data for Opacity Calculations 2 Finding the Missing Solar Ultraviolet Opacity and 3 Remaining Line Opacity Problems for the Solar Spectrum all three papers in Revista Mexican de Astronomia y Astrofisica 23 1992 Kurucz R L The Solar Irradiance by Computation Proceedings of the 17th Annual Review Conference on Atmospheric Transmission Models edited by Anderson G P Picard R H and Chetwynd J H PL TR 95 2060 Special Reports No 274 Pl 332 Phillips Laboratory Geophysics Directorate MA May 1995 Lucht W C B Schaaf and A H Strahler An algorithm for the retrieval of albedo from space using semiempirical BRDF models IEEE Trans Geosci Remote Sens 38 977 998 2000 Macke A D Mitchell and L Bremen Monte Carlo radiative tr
114. y be significant nearer to H2 the surface or tangent height M1 M2 M3 M4 MS M6 and MDEF are used to modify or supplement user specified altitude profiles for temperature pressure and molecular gases H20 O3 CH4 N20 CO CO O2 NO SO NO NH3 HNO3 and 13 heavy molecules For normal operation of the program using the standard model atmospheres MODEL to 6 one may set M1 M2 M3 M4 M5 M6 MDEF 0 MODTRAN then resets M1 through M6 to the value MODEL and MDEF to 1 If MODEL equals 0 horizontal path or 7 radiosonde data and if M1 through M6 and MDEF are set to zero or left blank then the JCHAR parameter on each CARD 2C1 must be defined to supply the necessary profiles If M1 through M6 and MDEF are non zero then the chosen default profiles will be utilized whenever the specific JCHAR input is blank MI 1to6 Default temperature and pressure to specified model atmosphere M2 1to6 Default H20 to specified model atmosphere M3 1t06 Default O to specified model atmosphere M4 1to6 Default CH to specified model atmosphere M5 1to6 Default N20 to specified model atmosphere M6 1to6 Default CO to specified model atmosphere MDEF 1 Default CO O2 NO SO NO NH3 and HNO species profiles If MDEF 1 default heavy species profiles are used If MDEF 2 the user must input the profiles for the heavy species which include nine chlorofluorocarbons CFCs plus CIONO2 HNOa CCla and N

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