Product User Manual for “SEVIRI Physical Retrieval
Contents
1. PGE13 SEVIRI Physical Retrieval SPhR Hd PGEI3 v1 2 dl e RU i und and Internal Interfaces of the SAF NWC MSG AD 4 SAFNWC MSG Output Products format SAF NWC CDOP INM SW ICD 3 15 12 11 Ll o LN LR AD 5 Architectural Design Document for the INM SAF NWC CDOP INM SW AD 4 ADOT RitcdrGtsoftheSAFNWCIMSG ow ii 7 mda d oF Lind SAENWC MSG Application AD 7 Validation Report for PGEI3 SEVIRI SAF NWC CDOP INM SCI VR 1 1 O 15 02 12 Physical Retrieval SPhR PGE13 v1 2 AD 8 NWCSAF Product Requirements Document SAF NWC CDOP INM MGT PRD 17 11 11 Table 1 List of Applicable Documents SAF NWC CDOP INM SW SUM 2 1 4 2 Reference Documents Table 2 List of Reference Documents Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 Qe 255 AEMet SEVIRI Physical Retrieval 588 ida ib File SAF NWC CDOP INM SCI PUM 13 v1 2 Product SPhR PGEI3 v1 2 Page 9 33 NWCSAF a 2 DESCRIPTION OF PGE13 SEVIRI PHYSICAL RETRIEVAL SPHR PRODUCT 2 1 GOAL OF PGEI13 SEVIRI PHYSICAL RETRIEVAL SPHR PRODUCT The PGEI3 SEVIRI Physical Retrieval SPhR product aims to provide information about water vapour and thermal stability distributions on clear air pixels from MSG SEVIRI infrared channels and NWP fields Products are generated at high spatial and temporal resolution to support real time meteorological applications The main outputs provided are Total Precipitable Water TPW Layer P2. 500 hPa 400 hPa 300 hPa amp Geopotential surface 250 hPa amp Land sea mask surface 200 hPa amp N2 metre dewpoint temperature surface 150 hPa amp N2 metre temperature surface 100 hPa amp Skin temperature surface runa 50 hPa 7 Soil temperature level 1 layer between two 30 hPa amp Surface pressure surface 10 hPa 0 59x0 5 box amp Total column water vapour surface Figure 4 REGION and fields from ECMWF used in NWCSAF Reference system 4 1 5 Geographical data from NWCSAF functions Longitude latitude and satellite zenith angles associated to selected region are computed on real time by functions available on the NWCSAF library As many NWC SAF PGEs need this geographical information NWCLIB computes and archives it on SSAFNWC tmp binary files avoiding to repeat the calculation If these files are erased or a new region is needed new binary files are created automatically by the first PGE that needs them 4 2 DESCRIPTION OF COEFFICIENTS FOR PGEI13 SPHR Although the detailed format of the PGEI3 SPhR coefficients files can be seen in AD 3 it is conducted here a brief summary of some characteristics that the user must know and take into account for proper operation of the PGEI3 SPhR The scientific aspects about how these coefficients files were obtained can be seen in AD 2 4 2 1 Bias correction coefficients The original satellite measurements must be bias adjusted to account for
3. Among all software packages that can read the netCDF format we can find 1 IDV http www unidata ucar edu software idv 2 McIDAS V http www ssec wisc edu mcidas software v 3 MATLAB 4 IDL Examples of the use with IDV can be found in http http www nwcsaf org 2010Users WSpresentations martinez ppt To this end users can activate two options called SAVE_END_PROF and SAVE_PROF editing the ASCII PGEI3 model configuration file in order to write the binary files Detailed information on the format of the PGE13 SPhR binary files can be found in AD 4 Bellow only a description is made 9 ee fhspags Pubs Tov e iO EX wd eg 4 S an y Owckhnks dB Data Cncosers 3 rie Selector Eos a FS Data Sources Vika Uh Chaplin Termina T Fun wews P dy DS 20t TOA A Contou Plan view Er Toe at PG Sep Color Filad Cortour Pia Ero Tunn at tiikerien Color Shaded Plan Verw Take ot Ses Bcrebca Wane Pore Ton at ed derwion 32 grid Cie Eth ari resveF i iar hain an Eii rie rix tg T ito Trea Lew Regen rie i Tar era hrs ig Tu 655 4 hPa ig Ts 102 7 hPa tpi Ta haa hPa FELS 185 1 hPa fg aaF 840 kPa p ua isiin WMizfh pl aa on i ies Pa T5307 GMT Figure 3 IDV visualization of retrieved q profiles with netCDF for 25 May 2009 at 12 UTC 2 3 3 1 3D binary file with END PROFILE SAVE END PROF Fixing SAVE END PROF to 1 the final retrieved profiles T and q profile at the 43 RTT
4. can be written in the SSAFNWC tmp on binary files after activation in the configuration file 3 Post processing e Quality control Several quality flags have been added to the output product e Filling clear pixels inside the FOR The default method is to copy the same value to all clear pixels in the FOR The other configurable option is to write the output only at the clear pixel position the warmest pixel in the case of the BTs of the warmest clear pixel at IR10 8 e Over cloudy pixels the IR BT degraded to 7 bits range 128 255 values for the channel included in the configuration file is stored This will be later used to generate adequate images in which cloudy pixels are grey scaled and clear pixels are colour scaled e The output is coded as images in HDF5 format file Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 QD 2505 AEMet SEVIRI Physical Retrieval 588 ida i File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 12 33 NWCSAF Product SPhR PGEI3 v1 2 2 3 DESCRIPTION OF PGE13 SPHR OUTPUTS The main outputs provided are parameters informing about the water vapour content in the vertical column total and in selected thickness and about the atmospheric thermal stability These parameters are computed using the final retrieved temperature and humidity profiles As additional outputs PGEI3 SPhR also provides the differences between the above parameters computed from the final retrieved
5. PGEI3 v1 2 Thermal Stability Index Ten Tare In the case of Lifted Index LI the temperature and humidity of the virtual lifted parcels are the average of the lowest 100 hPa or 1000 m Next table provides empirical relation between LI values and the stability degree LL ue oo O OUO In the case of Showalter Index SHW the lifted parcel represents the environment at 850 hPa Next table provides empirical relation between SHW values and the stability degree Showalter value K Index KI measures the thermal stability in function of the vertical gradient of temperature and humidity content in low levels KI T850 _ T T _ DD where DD T Ty The following table provides empirical relation between KI values and storm probability 20 25 2 3 20 PGE13 SPhR Main outputs HDF 5 files descripition The following fields are calculated for clear pixels in the current version 1 SPhR TPW Total precipitable water Psurface Proa from the retrieved profiles of temperature and humidity 2 Precipitable water in three layers LPW SPhR BL Psurface 850 hPa SPhR ML 850 500 SPhR HL 500 Proa from the retrieved profiles of temperature and humidity SPhR LI Lifted Index from the retrieved profiles of temperature and humidity SPhR SHW Showalter Index from the retrieved profiles of temperature and humidity SPhR KI K Index from the retrieved profiles of temperature a
6. a gzip compressed tar file and to successfully build the executable PGE13 file to be stored into the SAFNWC bin directory The installation steps for PGEI3 can be found in the Software User Manual AD 1 3 2 THE PGE13 EXECUTION STEP The execution step is the real time processing with actual SEVIRI images The PGEI3 running time scheduling relies on the Programmed Task Definition File This process consists in PGE13 command running along with the required parameters slot region file and model configuration file by the Task Manager Figure 1 summarises the inputs the outputs and the parameters needed to execute the PGEI3 command PGEI3 has been designed as much modular and configurable by the user as possible In order to configure it as much parameters as possible are collected in the PGE13 Model configuration file see section 4 3 1 The PGEI3 SPhR model configuration file allows an easy management of all PGEI3 keywords that can be changed by the user Each model configuration file is an ASCH file so further modifications can be easily performed with a text editor Before PGE13 execution it is also necessary to run PGEOI product for the same slot and region In near real time operation the order in the execution is coordinated by the Task Manager The PGE13 execution is hence performed calling the PGE13 executable command following the corresponding configuration file The use of the PGEI3 command is very easy in scripts Here an exam
7. instead of the hybrid levels that provide higher quality Users can select their preferred NWP model to be used as input The PGEI3 SPhR has been designed to be able to use background NWP GRIB files with any number and distribution of fixed pressure levels But as it can be concluded from the reading of the Validation Report AD 7 the user is stronger recommended to provide as many fixed pressure levels with the most uniform and widest vertical distribution as he can provide from the selected NWP model to feed the NWCSAF package The NWP GRIB files must be located in saFNWC import NWwP data In real time operational mode once the NWP GRIB files are in this directory the NWC SAF package has predefined tools coordinated by the NWC SAF Task Manager daemon which check every minute for new NWP data making automatically the spatial remapping to the predetermined regions to process on to SSAFNWC tmp directory This avoids spending time in every call to PGE to make the remapping process In off line operational mode the AllMapping script allows to do the spatial remapping The list of NWP fields is configurable and it can be modified editing the NwP PARAM keywords in the configuration file As example of background NWP supply the current list of the fields supplied to the NWC SAF Reference System at AEMET headquarters is shown bellow Through a call to MARS that is automatically launched on ecgate ecmwf int machine as soon a new run of ECMW
8. pixel over land and lakes is obtained by averaging GTOPO30 values located inside this pixel whereas oceanic pixels are given a zero value These ancillary data are available in the NWC SAF software package on MSG full disk in the default satellite projection at full IR resolution They are extracted on the processed region by the PGE13 SPhR software itself These files are located in SAFNWC import Aux_data Topo directory in 3712 x 3712 size Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 26 33 Product User Manual for Mel SEVIRI Physical Retrieval NWCSAF Product SPhR PGEI3 v1 2 4 3 LIST OF PGE13 SPHR CONFIGURABLE PARAMETERS PGEI3 SPhR has been designed in a highly modular manner and allows a user selectable configuration The user configurable parameters are determined through the PGE13 model configuration file It is the third argument required by the PGEI3 program Thus changing the configuration used to execute the PGEI3 code is as easy as changing the third argument when the PGE13 is run Thus several PGE13 configuration can be available by the user in the sarnwc config and PGEI3 can be executed on real time with different configuration depending on the region to process the hour of the image etc As example users can execute PGE13 on the full disk with a large FOR width and with only one iteration step or on the other side to execute PGEI3 ov
9. profiles and the similar ones computed from the forecasted background profiles These deviations are important for 1 signalling areas with discrepancies between model forecast and the observations and 2 show the added value of SEVIRI observations Optionally PGEI3 SPhR can be configured to keep the final retrieved profiles and the intermediate profiles This allows users 1 to feed new applications or to compute specific stability indices at their own and 2 to debug testing and monitoring PGE13 SPhR performances 2 3 1 PGEI3 SPhR Main outputs description 2 3 1 1 Introduction Humidity and Thermal Stability parameters 2 3 1 1 1 Humidity parameters An evaluation of humidity distribution is critical in order to determine the possibilities of convection severe weather and heavy precipitation Storms usually develop where humidity is already high or where some mechanism makes it to increase Precipitable water is a measurement of the water vapor mass contained in a vertical column of atmosphere of section unit and thickness limited between two pressure levels The units are kg m mm are commonly used in operational meteorology Four different precipitable water parameters defined as function of two selected pressure levels are considered of interest Total Precipitable Water TPW Pus puse and Dua cU Low Layer Precipitable Water BL Dua Dui SNC Dain B90 Pa Medium Layer Precipitable Water ML Pmax 850 hPa and pmin 500 hPa
10. the bias between the satellite observation and the synthetic radiative transfer model BTs see AD 2 Such biases must be assessed in an independent step e g by comparing the clear sky BTs with the calculated BTs using the same radiative transfer model and collocated forecast analysis atmospheric profiles one example can be seen in AD 7 There is not a specific coefficient file Once the scale and the offset parameters for each SEVIRI IR channel were obtained the values are written in one PGEI3 SPhR model configuration file BT GLOBAL SCALE and BT GLOBAL OFFSET keywords and NWCLIB functions to read this bias correction coefficient and to apply the bias correction are available see section 4 3 1 for more details 4 2 2 PGE13 First Guess regression coefficients file This file contains the regression coefficients used to generate the First Guess from the Background NWP fields and the SEVIRI IR BTs see AD 2 The name of the file appears in the PGE13 configuration file keyword RCF FILENAME The files are named RC m9 SFOV 6ch monthYYYY bin Where gqm9refers to MSG 2 m8 to MSG 1 Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 5 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 24 33 Product User Manual for Mel SEVIRI Physical Retrieval Product SPhR PGEI3 v1 2 NWCSAF a monthYYYY is the date when the file was generated The files contain regression coefficients for every zenith degree
11. 13 SPHR As a whole PGE13 SPhR code is designed in a modular way so that it can be easy to handle and modify it The algorithm of the PGE13 SPhR is based on physical retrieval and it is described in AD 2 In this section only a brief outline and the points related to process of the data is provided For the selected region the initialization gives access to SEVIRI BTs PGEOI Cloud Mask CMa satellite zenith angle and ancillary data topographic data land sea mask longitude latitude Only if the pixel or the Field Of Regard FOR in case of MxM pixels processing is labelled as clear air and the satellite zenith angle of this pixel or FOR is below the configurable maximum zenith threshold the Physical Retrieval module is applied and the PGEI3 TPW LPWs LI SHW and KI parameters are calculated for this pixel or FOR The main input values are the BTs from five SEVIRI infrared channels centred at 6 2 7 3 10 8 12 0 and 13 4 um and forecasted NWP fields which are used as background information PGE13 SPhR also uses a land sea mask as static input information and land emissivity maps pre computed for each IR SEVIRI channel and for every month of the year Cloud Mask CMa computed by PGEOI is used as mandatory input to PGEI3 SPhR and the process is only performed for pixels or FOR in case of MxM pixels processing labelled as clear air NWCSAF ers de Melonia Product SPhR PGEI3 v1 2 PGEO 1 Cloud Mask Code SAF NWC CDOP
12. 9 12 UTC produced from SEVIRI on N e E T A Jd Figure 11 Example of PGE13 SPhR_KI 23 July 2009 12 UTC produced from SEVIRI on Me E P A EN E EEA A E LE E 32 Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 bipes 255 AEMet SEVIRI Physical Retrieval 588 ing lie File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 6 33 NWCSAF Product SPhR PGEI13 v1 2 1 INTRODUCTION The EUMETSAT Satellite Application Facilities SAFS are dedicated centres of excellence for the processing of satellite data and form an integral part of the distributed Eumetsat Application Ground Segment SAFs are also dedicated centres for software development This documentation is provided by the SAF on Support to Nowcasting and Very Short Range Forecasting NWCSAF The main objective of the NWCSAF is to provide develop and maintain software packages to be used with operational meteorological satellite data for nowcasting applications by National Meteorological Services More information about the project can be found at the NWCSAF webpage http www nwcesaf org This document is applicable to the NWCSAF processing package for Meteosat Second Generation satellites NWCSAF MSG 1 1 SCOPE OF THE DOCUMENT This document is the Product User Manual PUM for the PGEI3 SEVIRI Physical Retrieval SPhR product of the NWCSAF MSG software package It describes the goal
13. 9 3 coefficients PGE13 SPhR software strongly relies on a clear sky fast and accurate radiative transfer model In our case RRTOV software from EUMETSAT NWPSAF is used The current version of PGE13 SPhR uses RTTOV version 9 3 which is also used by other NWCSAF MSG PGEs The RTTOV 9 3 coefficients files rtcoef msg 1 seviri dat and rtcoef msg 2 seviri dat must be located in SAFNWC src RTTOV93 rtcoef rttov7 These files are also needed by other NWCSAF MSG PGEs 4 2 8 Ancillary data sets The elevation mask remapped onto geostationary satellite image projections is an ancillary data needed to run PGEI3 In 2010 PGEI3 version the elevation data set is used to distinguish between land and sea pixels sea pixels are those whose elevation value is equal to missing code Then in the case of land pixels the emissivity values are read from the emissivity data sets Atlas and sea land mask datasets covering the whole MSG disk in the default satellite projection at full SEVIRI IR horizontal resolution are available within the NWC SAF software package The source is GTOPO30 available on http eros usgs gov Find Data Products and Data Available GTOPO30 which is a global digital elevation model Elevations in GTOPO30 are regularly spaced at 30 arc seconds approximately 1 kilometre For more detailed information see the GTOPO30 documentation web page http eros usgs gov ecms documents products GTOPO30_README doc The altitude of each SEVIRI IR
14. AF NWC CDOP INM SCI PUM 13 v1 2 Page 27 33 Product User Manual for ALMel SEVIRI Physical Retrieval NWCSAF Product SPhR PGEI3 v1 2 physical retrieval process will be executed three times this implies 3 calls to RTTOV K and 3 inversion of the matrix for every clear FOR for every clear FOR and the execution time can increase enormously The name of all coefficients files are keywords in the configuration files Thus to change a coefficient file 1s only needed to change the name of the coefficient file in the model configuration file The list of the main configurable coefficients files 1s a RCF FILENAME for the FG regression coefficients file b EOF Wv FILENAME for the Water Vapour Empirical ortogonal functions log q EOFS c EoF T FILENAME for the Temperature Empirical ortogonal functions T EOFs and INV COV MATRIX for the inverse covariance matrix B Method to calculate the BTs of the FOR FOR METHOD keyword There are two possibilities a the mean of all clear pixels b the SEVIRI BTs of the warmest clear pixel at the IR10 8 channel Optional writing of the PGEI3 SPhR binary files As it was explained in section 2 3 3 there are two keywords SAVE PROF and SAVE END PROF that in case of being activated several PGEI3 binary files with the retrieved T and q profiles are created in the SSAFNWC tmp directory Background NWP parameters vertical levels and spatial interpolation method The number and the li
15. C CDOP INM SCI PUM 13 v1 2 Page 25 33 Product User Manual for Mel SEVIRI Physical Retrieval NWCSAF Product SPhR PGEI3 v1 2 4 2 6 Surface IR emissivity atlas files The monthly emissivity atlas from MODIS IREMIS 2006 dataset http cimss ssec wisc edu iremis from Wisconsin University has been spectrally interpolated and remapped to MSG full disk Files for every month and channel have been generated The emissivity matrices for 0 W and 9 5 E reprojection longitude centres for each IR channel from 6 2 to 13 4um are written on 2 bytes integer binary files Emissivity atlas files are available for months SEVIRI channels and re projection longitude point The name of the files is global emis month 000 0w i dta global emis month 009 5e i dta Where e month is the number of the month written with two digits e iis the number of the IR SEVIRI band from 5 to 11 written with two digits As example the number 5 indicates WV6 2 and the number 11 is for IR13 4 channel The emissivity values are positive for pixel over land and in order to archive such short integer the value is equal to emissivity multiplied by 1000 Over sea pixels the value is missing code masked as 9999 The files are located in the SAFNWC import Aux_data PGE13 directory These ancillary data are available in the NWC SAF software package on MSG full disk 3712x3712 in the default satellite projection at full IR resolution 4 2 7 RTTOV
16. C SAF Fere Dtr de Meteors Product SPhR PGEI3 v1 2 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 31 33 Imm E f SAFNWC PGE13 PGELSSPAR AL 23 JUL DS Al 12 Fi igure 7 Example of PGE 3 SPhR HL 23 July 2009 1 2 UTC C UNES pu MSG2 SEVIRI on MSG2 OTAL PRECIP WATER 70 Imm 0 saa PGELSSPRR IPW 2s JUL 09 AT le Figure 8 Example of PGEI3 SPhR_TPW 23 July 2009 1200 UTC produced from SEVIRI on MSG2 MAFNWC PGE13 PGE1SSPHR LI 23 JUL 09 AT 12 Figure 9 E nat of PGEI3 SPhR LI 23 July 2009 12 U TC C T from SEVIRI on MSG2 Product User Manual for Code SAF NWC CDOP INM SCI PUM 13 A Met SEVIRI Physical Retrieval 99e 12 Date 15 February 2012 M File SAF NWC CDOP INM SCI PUM 13 v1 2 NWC SAF estin ce Meteorologia Product SPhR PGE13 v1 2 Page 32 33 SHOWALTER FES E n T ere l E d BAFNHC PGE13 PGE1SSPHR SHOWALTER 23 JUL 09 AT iz mem 10 Example of PGEI3 SPhR SHW 23 July 2009 12 UTC produced from SEVIRI on MSG2 lt INDEX oe yr a d je dms i aie di x SRFNHC PGE13 PGE1SSPHR KINDEX 23 JUL 09 AT 12 zer lI DT of PGEI3 SPhR_KI 23 July 2009 12 UTC produced from SEVIRI on MSG2 Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 33 33 Product User Manual for ALMel SEVIRI Physical Retrieval Product SPhR PGEI3 v1 2 NWCSAF Armei Eui d Meters 7 REFERENCES G
17. Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 Product SPhR PGEI3 v1 2 Pc l Milo c M M cae f Product User Manual for SEVIRI Physical Retrieval The EUMETSAT Network of Satellite Application Facilities B w Support to Nowcasting and Very Short Range Forecasting Product User Manual for SEVIRI Physical Retrieval Product SPhR PGE13 v1 2 SAF NWC CDOP INM SCI PUM 13 Issue 1 Rev 2 15 February 2012 Applicable to SAFNWC MSG version 2012 Prepared by AEMET Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for i 12 Bun es 2008 AEMet SEVIRI Physical Retrieval SS dg ii File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 2 33 NWCSAF Product SPhR PGEI3 v1 2 REPORT SIGNATURE TABLE M A Martinez AEMET Prepared by Ramiro Romero AEMET Jun Li CIMSS 15 February 2012 l 15 February 2012 Reviewed by Marcelino Manso Pilar Fern ndez 15 February 2012 Authorised by l SAFNWC Project Manager Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for i 12 Bun es 2008 AEMet SEVIRI Physical Retrieval 588 oe File SAF NWC CDOP INM SCI PUM 13_v1 2 NWC SAF Product SPhR PGE13 v1 2 Page 3 33 DOCUMENT CHANGE RECORD CHANGES Initial version iei sagt Submitted to DRI 2010 Review Board 21 May 2010 Corrected after DRI 2010 Updated version for 2011 1 1 1 April 2011 32 New emissivity files to operate with MSG1 MSG2 and Rapid Scan
18. F model is available ECMWF GRIB files from 0 24 range hours forecast every 6 hours are transferred to SSAFNWC import NWP data The ECMWTE fields on each GRIB file that are supplied to the NWC SAF reference system are the following 1 Surface pressure SP 2 Skin Temperature SKT 3 Temperature at 2 meters T2M 4 Soil Temperature Level 1 STL1 5 Total Column Water Vapour TCWV 6 2 meter Dew point 2D 7 Temperature T profile at the following pressure levels 1000 925 850 700 500 400 300 250 200 150 100 70 50 30 10 8 Relative humidity R profile at the pressure levels 1000 925 850 700 500 400 300 250 200 150 100 70 50 30 10 9 Wind profile U and V components at the pressure levels 1000 925 850 700 500 400 300 250 200 150 100 70 50 30 10 10 Geopotential Z profile at the pressure levels 1000 925 850 700 500 400 300 250 200 150 100 70 50 30 10 The fields are retrieved from MARS on a grid of 0 5 x 0 5 and for a region delimited by 82 N 76 W and 22 S 75 E Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 Qe 2505 ALMet SEVIRI Physical Retrieval 588 dd lb File SAF NWC CDOP INM SCI PUM 13 v1 2 Product SPhR PGEI3 v1 2 Page 23 33 NWC SAF 9 3D grid o Derived gg Geopotential isobaric amp Relative humidity isobaric Gg Temperature isobaric amp U velocity isobaric amp V velocity isobaric 2D grid 1000 hPa 925 hPa 850 hPa 700 hPa
19. High Layer Precipitable Water HL Pmax 500 hPa and pg 0 Most of the contribution to TPW comes from a layer between surface and 500 hPa 2 3 1 1 2 Thermal stability parameters Thermal stability indices were developed in the past to support storms and severe weather forecast using as main input local radiosonde profiles of temperature and humidity It is important to remark as introductory note that the use of these indices needs to be supported by previous experience in the use of the more appropriate ones to each specific region and weather regimes Among all the instability indices Lifted Index Galway 1956 and Miller 1972 the Showalter Index Showalter 1947 and the K Index George 1960 has been chosen to codify in the 2010 version These indices are widely used in operational meteorology There are several thermal stability indices defined as the difference between the air environment temperature at 500 hPa and the temperature of an air parcel representative of the properties of low levels lifted up to the 500 hPa The indices have negative values when the lifted parcel arrives warmer than the environment as it means buoyancy and hence instability The units are Kelvin C is commonly used also in operational meteorology Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 Pese 2005 AEMet SEVIRI Physical Retrieval 88 oo File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 13 33 NWCSAF Product SPhR
20. INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 10 33 Product User Manual for Met SEVIRI Physical Retrieval 1000 hPa 925 hPa 850 hPa 700 hPa de perd CaccoetantuM VF Seba dh Petarive hamid de isobaric Te xar vey F pbir M vierie dh issbar 500 hPa t 2D ard 400 hPa Larci sad friki P duntiscs 300 hPa idm nt m ais 551250 hPa a i be at EM me 200 hPa F s 2 Spatial Int rpolation Ses vemperasore Hal 1 4 Inr Dew61150 hPa BL sfc 850 i 2 at a pere E en 100 hPa m 4 zzi uw 70 hPa 50 hPa 30 hPa y i 10 hPa PGE13 i YYYYMMDDhhmm region config file Ancillary amp coefficients ML 850 500 Lon lat zenith Bias correction regression EOF etc differences phy Ret NWP Figure 1 PGEI3 SPhR execution outline The whole process includes the following main steps l Pre processing Initialisation reading of processing options from the configuration file reading of all coefficient file names get IR emissivity maps for region initialisation of RTTOV 9 3 obtention of calibrated SEVIRI BTs and associated geographical ancillary data for region to process and reading of PGEO1 CMa for region Optional thinning of SEVIRI BT to process on FOR of M x M pixels M is a configurable parameter in the configuration file Two methods are available to calculate BTs of the FOR 1 mean value of clear pixels BTs on FOR or 2 BTs of th
21. OR Model Con pur alion P168 ssena 26 o PGLISSPHRPBHODUCT VALIDA LIDJI i e3WEETERENNSNENEREREYENEN NEUEN MHIREFFEYPFEN EE NA EY EVEYPEPMENS 28 2d SUMMARY OF PGE13 SPHR PRODUCT VALIDATION i iiid d 9 40 9040 230 A A HARI I de 28 5 24 PGE13 SPHR PRODUCT ASSUMPTIONS AND LIMITATIONS eeeeeeeee eene nennen eene 28 D201 Fy rites ier ae ener elie e Mm eM 28 a yd 28 6 EXAMPLES OF PGE13 SPHR VISUALISATIOQON eee eee eene eoo ree ee e eee tease 30 f REFERENCES nccc aAa 33 Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 5 33 Product User Manual for Mel SEVIRI Physical Retrieval NWCSAF Product SPhR PGEI3 v1 2 List of tables and figures Tab D Listat Anplhieable LOO So eap ER a rrr tert IUNII MR SUN ipUb Eb It LM MUI M MUS 8 Table 2 Maximum and Minimum values for each parameter ccccccccccceececeeeeeesssssssseeeeeeeees 14 Table 3 3D binary file with END PROFILE SAVE END PROP description 16 Table 4 3D binary files SAVE PROF 1 with temperature and humidity profiles at different steps of the PGE13 algorithm description ee cernerent qued aisi qute INE qU eU Qe que gU posi tbeS ques eses 17 Table 5 binary files only at clear FOR position SAVE PROF 2 with T and q profiles at different steps or the POE 13 algorithm description savercsictecucesscivvucussaissstecucerdece
22. OV levels are written These are the profiles used to calculate TPW LPW instability indices and the difference with background NWP profiles In this case the binary file is a 3D array 43 43 1 lines in region elements in region containing values other than the missing code 0 on the clear air pixels where the PGEI3 SPhR algorithm has been executed Name of 3D binary file T q SKT of profile used for PGE13 end prof YYYYMMDDhhmm Clinc colc Ssizl sizc TPW LPWS and instability index 43 43 1 lines elements calculation Table 3 3D binary file with END PROFILE SAVE END PROF description 2 3 3 2 Optional binary file with T and q profiles at different steps SAVE PROF If keyword SAVE PROF is set to a value different from the default value 0 the profiles at different steps of the PGEI3 physical retrieval algorithm are written in binary files This allows users to monitor the changes between the spatial and temporal interpolated temperature and relative humidity at user fixed pressure level and the retrieved temperature and specific humidity profiles Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 biegen 255 AEMet SEVIRI Physical Retrieval 88 iind be File SAF NWC CDOP INM SCI PUM 13 v1 2 RWC SAR Metin Cuil de Meesi Product SPhR PGEI3 v1 2 Page 17 33 The steps at which user can monitor and access to data are i After the spatial and temporal interpolation the background NWP previous an
23. able Precipitable Precipitable Precipitable V1 2 summary of Water Water Water Water validation Results Low Layer Medium Layer High Layer Total BL RMSE ML RMSE HL RMSE TPW RMSE LI RMSE Against ECMWF Analysis Over Sea 0 91 kg m 1 64 kg m 0 15 kg n 1 84 kg m 1 00 K Full Disk validation Against ECMWF Analysis Over Land 0 79 kg m 1 43 kg m 0 16 kg n 1 64 kg m 1 09 K Full Disk validation Table 6 Summary of the PGE13 SPhR statistical parameters in period January 2009 to December 2009 for 1 out 2 pixels synthetic dataset As it can be seen in AD 7 the user must take into account that the PGEI3 SPhR can provide useful spatial information but SEVIRI has limited information to improve the vertical information beyond the forecast Due to this fact the PGEI3 SPhR only can improve slightly the background NWP information on the mid levels in the humidity profile 5 2 PGEI3 SPHR PRODUCT ASSUMPTIONS AND LIMITATIONS 5 2 1 Assumptions 1 The surface pressure used in the SPhR comes from the NWP model The better resolution the surface pressure field is in the background NWP model the lower the error will be 2 The emissivity is fixed Fixed IREMIS dataset has been selected from year 2006 5 2 2 Limitations 1 SPhR products are available over clear FORs only 2 Since it 1s an iterative physical retrieval computation is relative expensive and an increase in the width of the FOR could be n
24. alway J G 1956 The lifted index as a pre dictor of latent instability Bull Amer Meteor Soc 43 528 529 George J J 1960 Weather Forecasting for Aeronautics Academic Press 673 pp Mart nez M A Li J et al 2008 Physical retrieval algorithm development for operational SEVIRI clear sky nowcasting products Proc The 2008 EUMETSAT Meteorological Satellite Data User s Conference Darmstadt Germany Martinez M A Li J et al 2009 First operational results of the NWCSAF MSG PGEI3 SEVIRI Physical Retrieval algorithm Proc The 2009 EUMETSAT Meteorological Satellite Data User s Conference Bath United Kingdom Martinez M A Li J Romero R 2010 NWCSAF MSG PGE13 Physical Retrieval product version 2010 Proc The 2010 EUMETSAT Meteorological Satellite Data User s Conference C rdoba Spain Martinez M A Li J Romero R 2011 Status of NWCSAF MSG PGE13 Physical Retrieval product Proc The 2011 EUMETSAT Meteorological Satellite Data User s Conference Oslo Norway Miller R C 1972 Notes on Analysis of Severe Storm Forecasting Procedures of the Air Force Global Weather Central AFGWC Tech Rep 200 Rev Air Wea Serv Scott AFB IL 181 pp NOAA 1984 Convective stability indices Nat Wea Serv West Reg Tech Attach No 64 14 Salt Lake City UT 8 pp Showalter A K 1947 A stability index for forecasting thunderstorms Bull Amer Meteor Soc 34 250 252
25. and characteristics of the PGEI3 SPhR product including the needed input data and the resulting outputs It also provides comprehensive information on the algorithm implementation 1 2 SOFTWARE VERSION IDENTIFICATION This document describes the algorithm implemented in the PGE13 SPhR version v1 2 included in the NWCSAF MSG v2012 software package delivery itid de Master pu NWCSAF Product User Manual for SEVIRI Physical Retrieval Product SPhR PGE13 v1 2 Issue 1 2 Page 1 3 DEFINITIONS ACRONYMS AND ABBREVIATIONS ABI AEMET AIRS AMSR E ATBD BL BT CDOP CIMSS CMa CM SAF DEM ECMWF EOF EUMETSAT FOR FOV GTOPO 30 HDF HL HRIT IASI INM IR KI LI LPW ML MODIS MPEF MSG NWC SAF NWP PCA PGE RAOB RTTOV SAF SEVIRI SG SAI SHW SPhR SVD SW TBC TBD TPW URD VSA Advanced Baseline Imager Agencia Estatal de Meteorolog a former INM Atmospheric InfraRed Sounder Advanced Microwave Scanning Radiometer EOS Algorithm Theoretical Basis Document Boundary Layer 1013hPa 850 hPa Brightness Temperature Continuous Development and Operational Phase Cooperative Institute for Meteorological Satellite Studies Cloud Mask also PGEOI Climate Monitoring SAF Digital Elevation Model European Centre for Medium range Weather Forecast Empirical Orthogonal Functions European Meteorological Satellite Agency Field of Regard Field of View Global 30 Arc Second Elevation Data USGS EROS Data C
26. between 0 to 75 The number of regressions inside the file is 138x76 There is a regression for each one of the output variables and every satellite zenith angle from 0 75 The First Guess regression model included in PGE13 SPhR v1 2 does not use the IR8 7 and for this reason the associated coefficients have been set to 0 0 in order to maintain the format of the FG coefficient file and allow incorporating the use of IR8 7 in future versions The files with the FG regression coefficients must be located in S SAFNWC import Aux data PGE13 There are different First Guess regression coefficients for MSG 2 and MSG 1 The detailed format can be seen in AD 3 In AD 7 the process followed to get the 2012 FG regression coefficient file is described 4 2 3 PGE13 Empirical Orthogonal functions EOF for T and q As it is explained in AD 2 in the PGE13 SPhR algorithm the minimisation of the error between the SEVIRI BTs and the RTTOV BTs is made in the EOFs space The name of the files that contain the EOFs coefficients for temperature and specific humidity appears in the PGEI3 configuration file keywords EOF_WV_FILENAME for logarithm of specific humidity and EOF_T_FILENAME for temperature Each EOF file is a double 8 bytes array of 43 x 43 dimensions Its size is 14 792 bytes 43 x 43 x 8 The order is 43 elements of the first EOF T the EOF with largest eigenvalue then the 43 elements of the second and so on Same structure 1s o
27. d following forecast T and RH profiles spatially interpolated to the region as defined in the PGEI3 configuration file have been interpolated to the time of the image il After vertical interpolation and conversion of relative humidity to specific humidity the written profiles are T and q ppmv at the 43 RTTOV pressure levels These profiles are adequate to compare with the final retrieved T and q profiles and allow computing the differences with background TPW LPW and instability indices iii T and q ppmv profiles at the 43 RTTOV pressure levels after applying FG non linear regression step to the bias corrected SEVIRI channel and the profiles of step 11 iv Due to the design of the code the maximum allowed number of iterations is three Thus T and q profiles after each one of the three physical retrieval iterations could be obtained v The final T and q retrieved profiles 43 levels used to calculate the main outputs Once the keyword SAVE PROF is activated the binary files will be written in the SsAFNWC tmp directory Due to the huge size of the 3D binary files for large regions as example Full Disk region the SAVE PROF keyword allows two values with SAVE PROF 1 the 3D binary arrays are written with SAVE PROF 2 only the profiles at the processed clear FOR are written The description of the structure of the 3D binary files option SAVE PROF 1 is in table bellow These 3D binary files are adequate for small to mediu
28. d the IR8 7 channel is considered as a mandatory channel See the Algorithm Theoretical Basis Document AD 2 for details Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 22 33 Product User Manual for Mel SEVIRI Physical Retrieval NWCSAF Product SPhR PGEI3 v1 2 4 1 3 PGEO01 Cloud Mask CMa NWC SAF PGE13 SPhR is only generated in clear sky pixels As cloud mask is a mandatory input to PGEI3 NWC SAF PGEOI Cloud Mask CMa must be executed before PGE13 In operational mode the Task Manager tool synchronises the execution of the products and the first product that is generated upon the arrival of a new image is the cloud mask NWC SAF PGEOI The PGEO1 Cloud Mask HDF 5 file for the image and the region to process must be located in SSAFNWC export PGEO1 directory 4 1 4 Background NWP GRIB files Background numerical weather prediction profiles from t 00 to t 24 hour forecast are needed These NWP data need to be spatially temporally and vertically interpolated to get NWP data collocated with SEVIRI data To maintain continuity with previous version of the NWCSF MSG packages to use the same NWP GRIB files dataset used by PGEO1 12 and to avoid the need for changes in NWCLIB software version 1 2 of PGEI3 SPhR uses as input relative humidity parameter instead of the specific humidity used internally by the software and information at fixed pressure levels
29. da be File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 18 33 NWC SAF Product SPhR PGEI3 v1 2 background NWP number pressure levels is the number of pressure levels associated to the SPHR NWP LEVELS keyword in the cfm file As example in the tables 3 to 5 in the case of a region of 600 lines x 900 elements centred in 557 1774 the name of binary files will contain cossz 1774 soeoo 0900 Name of binary fle only at clear FOR processed background NWP T and q ppmv profile at the 43 RTTOV levels Ozone i j 43 43 1 PGE13 CLEAR FOR background YYYYMMDDhhmm Clinc colc Ssizl sizc 43 profile empty 2m Temperature 2m q Surface pressure skin temperature PGE13 CLEAR FOR fg YYYYMMDDhhmm Clinc colc Ssizl sizc T q SKT of profile at i j 434 43 1 n_clearFOR First Guess step PGE13 CLEAR FOR retr iter 1 YYYMMDDhhmm Clinc colc Ssizl size fu t p rone i j 43 43 1 n_clearFOR result of 1 iteration step PGE13 CLEAR FOR retr iter 2 YYYYMMDDhhmm Clinc _ colc Ssizl sizc PEU P Tonie i j 434 43 1 n_clearFOR result of 2 iteration step PGE13 CLEAR FOR retr iter 3 YYYYMMDDhhmm Clinc colc Ssizl sizc fup 1 p rofile i j 434 43 1 n_clearFOR result of 3 iteration step RTTOV synthetic BT of i4 5 n clear FOR PGE13 CLEAR FOR retr bt YYYYMMDDhhmm Clinc colc Ssizl sizc the five channels used in MM the physical retrieval Note double 8 bytes Table 5 binary files only at clear FOR position SAVE PROF 2 with T and q prof
30. e warmest clear pixel at IRIO 8 Keywords LSIZE FOR CSIZE FOR and FOR METHOD To get collocated background NWP forecast temperature and moisture profiles Background NWP fields of temperature and humidity T 00 to T 24 hours range forecast are spatially temporally and vertically interpolated Conversion from relative humidity to specific humidity is also made at this step The spatial horizontal interpolation to the FOR position is calculated outside of PGEI3 SPhR with common functions of NWCSAF library The interpolation in the vertical is made assuming the 43 pressure levels of RTTOV as fixed levels Bias adjustment of SEVIRI BTs The bias correction regression coefficients are read from the configuration file and BT bias correction is made Note the SEVIRI BTs bias correction coefficients calculated with ECMWF model data from 15 vertical levels are written in the default configuration file By editing this configuration file users can apply their own BT bias correction if available or even they have the possibility not to use bias correction by fixing SCALE keyword to 1 and OFFSET keyword to 0 Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 11 33 Product User Manual for ALMel SEVIRI Physical Retrieval Product SPhR PGEI3 v1 2 NWCSAF e Execution of non linear regression to calculate the first guess profiles of temperature and specific humidity usin
31. ecessary in large region processing 3 The result can exhibit large errors over mountain regions with large difference between the topography and the NWP topography The same happens in desert pixels where the distance on skin temperature between the NWP first guess and the actual skin temperature could be high Similar behaviour is expected on very hot or cold pixels over non desert land pixels From our experience changes in the supply of the background NWP from ECMWE every 6 hours from T 0 to T 24 with 0 5 x0 5 resolution to every 3 hours from T 0 to T 24 with 0 125 x0 125 resolution have improved clearly the quality of the Product User Manual for Code SAF NWC CDOP INM SCI PUM 13 AEM ef SEVIRI Physical Retrieval Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 statui de Meteontieggih NWC SAF Product SPhR PGE13 v1 2 Page 29 33 PGE13 SPhR outputs The following improvement should be the change from 15 pressure levels GRIB to 91 hybrid levels GRIB it is foreseen that ECMWFE increase the number of hybrid level to 144 In general the more accurate is the background profile the more accurate will be the retrieval 4 Effect of emissivity temporal variation is not handled Fixed IREMIS monthly datasets has been selected from 2006 Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 30 33 Product User Manual for SEVIRI Ph
32. eeeeeeeeesssssssseee eene eee enne nnne nnns 12 FAR We PGE13 SPhR Main outputs HDF 5 files A SCTipition cccccccccccccccccccceccceeececeeeeeeeees 15 AS S Ondonal DING VCs OUIDIDS acis REOS M RESP n ni nasus nonna uns nb S 15 3 IVIPLEMENTA TION OFTHE PRODUC Doar a ENE 19 3 1 THE PGE13 INSTALLATION AND PREPARATION STEP eere etant n e e n 19 B2 MEFOBI FXECUNONSTEP senreste rere eneee sanada ea MEME iaai err ees 19 4 DESCRIPTION OF INPUTS COEFFICIENTS FILES AND CONFIGURABLE L5 4 LUE UM MOL Le nsn 21 4 DESCRIPTION OP INPUTS POR PE S THER ntis pq IER 2 4 1 1 Region con eurai on 21 4 1 2 SII IPLE TEMA Rr m 21 4 1 3 POLU COUI a ee 22 4 1 4 PO NWP ORIB OSes e e e o e e a E a e E eaa 22 4 1 5 Geographical data from NWCSAF functions sesseseeeeeseeeeseee enhn nee PA 4 2 DESCRIPTION OF COEFFICIENTS FOR PGE13 SPHR eene 23 4 2 1 Pe I DEDE e epee eee ere erence eee 25 4 2 2 FOEIS PS OESS TEBFESSIOR Coe En E aR dd 4 2 5 PGEIS Empirical Orthogonal functions EOF for T GRO e v oti t b Erebi 24 4 2 4 PGEI3 Inverse Covariance MatriX esatta db MEME E EE EE EE PERFES SHEER UrH Y EPERE FEIER SES 24 4 2 5 PGEIS3S Band coefficients file for noise error adjustment cesses 24 4 2 6 Dire Fo ESS IVEY GS OS ARR 25 4 2 7 ERIS E NUIT Ira aa 23 4 2 8 upra mv do OEE E E T A A 2 4 3 LIST OF PGEI3 SPHR CONFIGURABLE PARAMETERS eee ee eese 26 4 3 1 POLI SP
33. enter Hierarchical data Format High Layer 500 hPa High Rate Information Transmission Infrared Atmospheric Sounding Interferometer Instituto Nacional de Meterolog a Infrared K Index Lifted Index Layer Precipitable Water Middle Layer 850hPa 500hPa Moderate Resolution Imaging Spectroradiometer Meteorological Product Extraction Facilities Meteosat Second Generation SAF on support NoWCasting and VSRF Numerical Weather Prediction Principal Component Analysis Product Generation Element Radiosonde Observation Rapid Transmissions for TOVs Satellite Application Facility Spinning Enhanced Visible amp Infrared Imager Steering Group Stability Analysis Imagery Showalter Index SEVIRI Physical Retrieval Software Version Description Software To Be Confirmed To Be Determined Total Precipitable Water Users Requirement Document Visiting Scientist Activity Code SAF NWC CDOP INM SCI PUM 13 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 7 33 Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 Pese 20088 AEMet SEVIRI Physical Retrieval 88 oo File SAF NWC CDOP INM SCI PUM 13 v1 2 NWCSAF erein Einna ce Maece Product SPhR PGE13 v1 2 Page 8 33 1 4 REFERENCES 1 4 1 Applicable Documents Software User Manual for the SAFNWC MSG 15 12 11 Application Software Part AD 2 Algorithm Theoretical Basis Document for SAF NWC CDOP INM SCI ATBD 13 15 02 12
34. er a small region centred in the area of interest with small FOR width and with up to three iterations 4 3 1 PGE13 SPhR Model Configuration File A PGEI3 SPhR model configuration file contains all the coefficients and some constant values required by PGEI3 software to run It has by default the extension cfm The model configuration file must be placed at the sAFNWC config directory In AD 3 it can be found a table with all the keywords and the options allowed in the PGE13 SPhR configuration file Bellow only some of them are described together with some considerations that the user must take into account to fix them for operational mode Users who desire to run PGEI3 SPhR with their own SEVIRI BT bias corrections coeffients must edit the BT GLOBAL SCALE bb and the BT GLOBAL OFFSET Pb coefficientes Users who desire to run PGEI3 SPhR without SEVIRI BT bias corrections must set them respectively to 1 0 and to 0 0 LSIZE FOR and CSIZE FOR the default width of the FOR is 3 But the width of the FOR is configurable by the user As example changing the width of the FOR from 3x3 to 6x6 the process speed up in a factor of 4 MAX ITERATIONS number The maximum number of iterations allowed by the software is set to 3 due to the software design It establishes the number iterations for one pixel The maximum number of iterations is three Taking into account that the Jacobian are calculated in every physical retrieval
35. g as main inputs a bias corrected SEVIRI BTs and b the background NWP temperature and specific humidity profiles spatially temporally and vertically interpolated 2 Processing e If the calculated error between RTTOV BTs from first guess profile and SEVIRI BTs over non window channels are greater than a predefined threshold the Physical Retrieval module is executed keyword BT RMS THRESHOLD In the Physical Retrieval Module the physical retrieval is one minimisation and iterative process see AD 2 the physical retrieval iterative process is executed while the error between SEVIRI BTs and synthetic RTTOV calculated from the T q profile after the iteration is greater than a trheshold keyword MAX RESIDUAL and while the maximum number of iterations is not reached keyword MAX ITERATIONS e To check if the retrieved profiles of temperature and specific humidity are between limits and they have physical meaningful e To perform direct calculation of TPW LPWs LI SHW and KI parameters at FOR from the retrieved profiles of T and q e To compute the differences between the products TPW LPWs LI SHW and KI calculated from retrieved profiles of T and q and the ones calculated from the background NWP profiles of T and q o Optional writing of the intermediate T and q profiles The profiles in the 43 RTTOV levels at the different algorithm steps after physical retrieval after iterations after First Guess or the background NWP
36. iles at different steps of the PGEI3 algorithm description n clearFOR The number of records on each file can be different depending on the number of clear FOR processed and on BT RMS THRESHOLD keyword the MAX ITERATIONS chosen and the convergence of the pixel This is why the region coordinates i element j line are included in every record For synthetic or simulated brightness temperature binary files RTTOV BTs for WV6 2 WV7 3 IRIO 8 IR12 0 and IR13 4 channels obtained applying RTTOV forward to the retrieved profile are stored Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 19 33 Product User Manual for Mel SEVIRI Physical Retrieval NWCSAF Product SPhR PGEI3 v1 2 3 IMPLEMENTATION OF THE PRODUCT Two main steps are identified The user manually interacts with the SEVIRI Physical Retrieval software during the installation and preparation step and the PGEI3 SPhR execution step is automatically monitored by the Task Manager if real time environment is selected 3 1 THE PGE13 INSTALLATION AND PREPARATION STEP The right to use copy or modify this software is in accordance with EUMETSAT Policy for the SAENWC MSG software package Once the user has obtained the necessary permissions to download the software package the software installation procedure does not require special resources It is restricted to decompress the distribution file
37. ion on the HDF 5 format file can be found in AD 4 Their structure 1s schematically shown in the following figure Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 ieee 2012 AEMet SEVIRI Physical Retrieval fee SAF NWC CDOP n SCI DOE 1 2 i SCI 13 y1 NWCSAF oo fete Gitta de Meteorologia Product SPhR PGE13 v1 2 Page 15 33 SAFMWC MSG2 SPAR YYYYMMDDhhmm region h5 ER O1 PALETTE RR U2 PALETTE Hy OS PALETTE EA O4 PALETTE R S PALETTE ER O6 PALETTE R 07 PALETTE BB B PALETTE RR DS PALETTE R 10 PALETTE EA 11 PALETTE R 12 PALETTE HB 13 PALETTE ER 14 PALETTE A SPhR BL SPhR CAPE SPhR_DIFFBL SPhR DIFFHL ek SPhRE DIFFKI amp k SPHR_DIFFLI amp SPHR_DIFFML amp SPHR_DIFFSHW SPHR_DIFFTPW ek SPhFE HL ek SPhR kl M SPhR LI amp SPhR ML A SPhR QUALITY SPHR_SFLAG V SPhR SHwv ek SPhR TPW 01 PALETTE is applied to the BL 08 PALETTE is applied to the SPhR DIFFHL 02 PALETTE is applied to the ML 09 PALETTE is applied to the SPhR DIFFLI 05 PALETTE is applied to the HL 10 PALETTE is applied to the SPhR_DIFFKI 04 PALETTE is applied to the LI 11 PALETTE is applied to the SPhR_DIFFTPW 05 PALETTE is applied to the TPW 12 PALETTE is applied to the SPhR DIFFSHW 06 PALETTE is applied to the SPhR_DIFFBL 13 PALETTE is applied to the SPhR KI 07 PALETTE is applied to the SPhR_DIFFML 14 PALETTE is applied to the SPhR_SHW Figure 2 PGEI3 SPhR produc
38. iteration calling to RTTOV K and this is a CPU most expensive routine reducing MAX ITERATIONS can reduce the execution time BT RMS THRESHOLD and MAX RESIDUAL keywords These keywords control the level of the desired error between the bias corrected SEVIRI BTs and the RTTOV BTs BT RMS is the error between the biases corrected SEVIRI BTs and RTTOV BTs calculated from the background NWP profile at the non window channel i e WV6 2 WV7 3 and IR13 4 in SEVIRI The physical retrieval module is executed only if BT RMS is greater than BT RMS THRESHOLD The MAX RESIDUAL keyword is the threshold used to stop the iteration process in the physical module MAX RESIDUAL is the allowed error between the SEVIRI BTs and the RTTOV BTs Then if BT RMS THRESHOLD is fixed too high it speeds up the process because only the FG regression step is applied to a high percent of the FOR It is fixed too slow the maximum iteration number is applied to a high percent of the FOR slowing the PGE13 execution the most CPU expensive routine is RTTOV K called inside the physical retrieval module For an optimal election the analysis of the error histogram between the biases corrected SEVIRI BTs and the RTTOV BTs could be used as it has been calculated for the ECMWF model in AD 7 Thus if MAX RESIDUAL is fixed to a very low value example 0 0001 and the number of iterations is fixed to 3 the Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File S
39. m regions and in applications as vertical cross sections 3D visualizations etc Name of 3D binary file SAVE PROF 1 background NWP number pressure levels lines elements T profile of background NWP at the fixed PGE13 nwp t YYYYMMDDhhmm Clinc colc Ssizl sizc mn pressure levels Relative humidity profile of background background NWP number pressure levels NWP at the fixed pressure levels lines elements in temperature of backgroun P PGE13 nwp sk YYYYMMDDhhmm Clinc colc Ssizl sizc e perenne bac pu d NWP at 1 lines elements e surface PGE13_nwp_sp YYYYMMDDhhmm Clinc cole Ssizl sizc Surface pressure of background NWP 1 lines elements PGE13 nwp q YYYYMMDDhhmm Clinc colc Ssizl size PGE13 fg YYYYMMDDhhmm Clinc colc Ssizl sizc T q SKT of profile at First Guess step 43 43 1 lines elements st nd rd 5 lines elements PGE13 retr bt YYYYMMDDhhmm Clinc colc Ssizl size RTTOV synthetic Oe ae l i used in the physical retrieval Note double 8 bytes Table 4 3D binary files SAVE_ PROF 1 with temperature and humidity profiles at different steps of the PGE13 algorithm description Where YYYYMMDDhhmm is the nominal slot linc cole are the line and column coordinates of the centre of the region 0 based sizl size are the size of the region lines and columns Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for i 12 iun ees 2008 AEMet SEVIRI Physical Retrieval 588 i
40. mode Updated version for 2012 Update of BIAS correction coefficients for the 6 SEVIRI IR channels for MSG 1 and MSG 2 New FG non linear regression coefficients Computation of Empirical Orthogonal Functions EOFs for temperature and log q from ECMWEF New inverse covariance matrix computed and code update to manage inverse covariance matrix as configurable parameter Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 5 February 2012 File SAF NWC CDOP INM SCI PUM 13 v1 2 Page 4 33 Product User Manual for ALMel SEVIRI Physical Retrieval NWCSAF Product SPhR PGEI3 v1 2 Table of contents 12 PAPO TION crci pU NE EEPH ID RUIT EEE HEN D renee 6 1 1 SCOPE OF THE DOCUMENT ssssssssseeesssssseerreessssssstrreeessssseerteessssssserteeessssssertreessssssetrreesssssseete 6 1 2 SOFTWARE VERSION IDENTIFICATION eere n n n a a REA 6 Lo DEFINITIONS ACRONYMS AND ABBREVIATIONS sssseeesssesssssssssssseettttrrrreesssssssssssseeeeerereeeee q E E o AAE A AAAA E AAAA MN A 8 1 4 1 Applicable DIO CUIICIIN iais S 1 4 2 TH 2 BTUTHUI UI ERREUR S 2 DESCRIPTION OF PGE13 SEVIRI PHYSICAL RETRIEVAL SPHR PRODUCT 9 zx GOAL OF PGE13 SEVIRI PHYSICAL RETRIEVAL SPHR PRODUCT 9 zc E E T ee een enact 9 p DESCRIPTION OF POUEI SPRER OUTPUTS ousssbnbebsbnpabnbtbabtbaPRRPRERPEEREEEDPEEDERPDEDPDEDPhERPnERP nb POUR 12 2 3 1 PGE13 SPAR Main outputs description s
41. n EOF log q file but for log q The files with the EOF vectors are in SAFNWC import Aux_data PGE13 4 2 4 PGE13 Inverse Covariance Matrix As it s explained in AD 2 the statistical error of the background is represented by the matrix B in the PGEI3 SPhR algorithm In PGEI3 SPhR 2012 version this matrix has been computed with the available PGE13 SPhR training and validation dataset with ECMWF model outputs The name of the file that contains the inverse covariance matrix appears in the PGEI3 configuration file keyword INV COV MATRIX The file is a ASCII file of 87 x 87 dimensions Its size is 113 535 bytes 87 x 87 x 15 The file with the inverse covariance matrix is located in sAaFNWC import Aux data PGE13 directory 4 2 5 PGE13 Band coefficients file for noise error adjustment It contains SEVIRI radiance derivative with respect to brightness temperature coefficients This file contains MSG Planck function and band correction coefficients The name of the file is a configurable parameter in the PGEI3 configuration file keyword BCC FILENAME The default name is metsecgenbnd dat The size is 1200 bytes and it is divided in 3 records of 100 float Every record is for each one of the MSG satellites first record for MSG 1 second record for MSG 2 and third record for MSG 3 The file is located in SAFNWC import Aux data PGE13 directory Code SAF NWC CDOP INM SCI PUM 13 Issue 1 2 Date 15 February 2012 File SAF NW
42. nd humidity SPhR DIFFTPW Differences between TPW from retrieved profile and TPW from NWP profiles 7 SPhR DIFFBL SPhR DIFFML SPhR DIFFHL Differences between LPWs from retrieved profile and LPWs from background NWP profiles E uum Hs Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for i 12 Bun es 2008 ALMet SEVIRI Physical Retrieval 588 dd die File SAF NWC CDOP INM SCI PUM 13 v1 2 Product SPhR PGEI3 v1 2 Page 14 33 NWCSAF 8 SPhR DIFFLI SPhR DIFFKI SPhR DIFFSHW Differences between instability indices from retrieved profile and instability indices from background NWP profiles 9 Quality Flags SPhR QUALITY SPhR SFLAG fields 10 Configurable IR channel BT degraded to 7 bits only in cloudy pixels It is important to remark that taking advantage of the PGEI3 SPhR retrieved T H profiles new thermal stability indices can be added as well as the atmospheric layers of the precipitable water can be modified The fields are later on scaled in order to store them in 7 bits being the values in the range 8 127 The HDF 5 format files scales have the following minima and maxima values Parameter minimum maximum SPhR BI pos SPhR_ML SPhR_HL SPhR_TPW SPhR_LI SPhR_KI SPhR_SHW sm amp pmML as serpere 0 ts sm amp pFW 00003 Table 2 Maximum and Minimum values for each parameter The HDF 5 output files are stored in SAFNWC export PGE13 Detailed informat
43. of 448 lines by 576 elements centred over France Any valid region configuration file could be used for the PGEI3 generation See details on how to create valid region configuration files in AD 3 Since the region configuration file sets the name of the region dimensions and position these parameters are used later to build the ancillary data geographical topography emissivity atlas etc and they are part of the name of the output HDF 5 file and the optional PGE13 SPhR binary output file 4 1 2 SEVIRI BT HRIT SEVIRI files The following SEVIRI IR BT values are needed at full IR spatial resolution BT12 0 um_ BT13 4 um The PGE13 SPhR checks the availability of mandatory SEVIRI channels for each pixel No results are produced for pixels where one or more channels are missing The NWCSAF library reads BTs from HRIT files and extracts the region to process The NWC SAF library makes automatically the correction from spectral to effective radiance if the HRIT files do not have effective radiance bit flag The HRIT files for the image to process must be located by the user in SSAFNWC import SEVIRI_data in HRIT decompressed format In the 2012 PGE13 code BT of IR8 7 channel can be only used at FG regression step In the 2012 version default FG regression file the coefficients for IR8 7 BT have been fixed to 0 0 and the IR8 7 BT is not used In order to allow the use of future FG regression coefficients files with the IR8 7 channel include
44. ple of execution is provided PGEI3 YYYYMMDDhhmm region cfg configuration file ctm Where YYYYMMDDhhmm is the date and hour of SEVIRI image region cfg is the name of file with region to use See in section 4 1 1 and AD 3 about how the region can be defined configuration file cfm is the name of the ASCII file with the configurable parameters that PGEI3 needs Changing the options to process PGEI3 could be easily done by modifying with any editor the ASCII file configuration file or processing with any other configuration file Since the model configuration file is the third argument required by the PGEI3 program to change the configuration used to execute the PGEI3 code is as easy as to change the third argument when the PGEI3 is executed Thus several PGEI3 configuration can be available by the user in the ssarNwC config and PGEI3 can be executed on real time with different configuration depending on the region to process the hour of the image etc As example users can execute PGEI3 with a large FOR s width in a global or large region with only one iteration Product User Manual for Code SAF NWC CDOP INM SCI PUM 13 SEVIRI Physical Retrieval pile SAF NWC CDOP INM SCLPUM 13 v1 2 j 7 7 i rds Product SPhR PGEI3 v1 2 Page 20 33 Mel Issue 1 2 Date 5 February 2012 E Ba 7 NWC SAF and execute PGE13 over a small region centred in their countries with FOR s width 3x3 and three iterations When setting up
45. reasssiodncucucdierents 18 Table 6 Summary of the PGE13 SPhR statistical parameters in period January 2009 to December 2009 for 1 out 2 pixels synthetic dataset lt c cccsnnsssuvinnsascscrwdaancsdwawenannsaenvdnnsssscdanwacatecsnesesennnnnes 28 Figure 1 POLI SPhR execution outline siesta Mor HERE EHE FINE CENE EUER VE VU HDIDH inana 10 Figure 2 PGE 1S SPAR product file structure user rar pabnbn btt EE ERE EE CE FECE EEPEPAPEPEPES E EEEE EE FREE ERE epp dde dE 15 Figure 3 IDV visualization of retrieved q profiles with netCDF for 25 May 2009 at 12 UTC 16 Figure 4 REGION and fields from ECMWF used in NWCSAF Reference system 23 Figure 5 Example of PGEI3 SPhR BL from 12 UTC on 23 July 2009 produced from SEVIRI on Ule 30 Figure 6 Example of PGEI3 SPhR ML from 12 UTC on 23 July 2009 produced from SEVIRI on jig E 30 Figure 7 Example of PGE13 SPhR HL 23 July 2009 12 UTC produced from MSG2 SEVIRI on lj d c 3 Figure 8 Example of PGEI3 SPhR_TPW 23 July 2009 1200 UTC produced from SEVIRI on UNUS REP 3 Figure 9 Example of PGEI3 SPhR LI 23 July 2009 12 UTC produced from SEVIRI on MSG2 3 Figure 10 Example of PGEI3 SPhR_SHW 23 July 200
46. recipitable Water LPW in three layers low layer surface pressure 850 hPa middle layer 850 hPa 500 hPa and high layer 500 hPa Lifted Index LI Showalter Index SHW and K index KI These main outputs are computed from the retrieved profiles of temperature and humidity As additional outputs PGEI3 SPhR also provides the differences between the above parameters and the similar ones computed directly from forecasted NWP fields Quality control information parameters are also included in the product output Besides the above main output parameters PGEI3 SPhR can be optionally configured to save intermediate results that can be useful for debugging purposes or to feed new user applications PGEI3 SPhR products are useful in nowcasting applications used in synergy with other data available to the forecaster Since the physical basis of temperature and humidity retrieval 1s based in the minimization of the error between the SEVIRI BTs and the synthetic BTs calculated from the profiles and taking into account the limited number of channels and the spectral information of the SEVIRI instrument the PGEI3 SPhR only can slightly improve the humidity profiles beyond of the background NWP in middle and high levels Despite of this the retrieved fields have a higher spatial resolution compared with the forecast This fact must be taken into account by the users when the PGE13 SPhR outputs are used in nowcasting applications 2 2 OUTLINE OF THE PGE
47. st of fixed pressure vertical levels are fixed with the keyword SPHR NWP LEVELS Then for each one of the NWP fields must be a NWP PARAM keyword establishing the parameter the level and the spatial interpolation method bilinear interpolation or nearest neighbour As summary the user must establish a compromise between the machine characteristics CPU speed and memory where the NWCSAF MSG package will be operated the region or regions to process and the configurable keywords number of iterations BT RMS THRESHOLD and MAX RESIDUAL keywords and width of the FOR in the PGEI3 SPhR model configuration Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for i 12 Bun es 2008 ALMet SEVIRI Physical Retrieval 589 oe Product SPhR PGEI3 v1 2 id l a TT NWC SAF 5 PGE13 SPHR PRODUCT VALIDATION 5 1 SUMMARY OF PGE13 SPHR PRODUCT VALIDATION A complete thorough validation exercise has been done The applied methodology and the results are available in Validation Report for PGEI3 SPhR v1 2 AD 7 The validation is based on the comparison of PGE13 SPhR parameters with the calculated from ECMWF model The validation is focused on 2009 year and has been performed over 13 001 points Grid network of 1 x1 plus RAOB Stations In the table 6 a summary of the statistical values obtained from the validation for January 2009 December 2009 is presented see AD 7 for the whole validation report PGEI3 SPhR Precipit
48. t file structure 2 3 3 Optional binary files outputs Due to the fact that PGEI3 SPhR is executed locally and in order to allow users to debug their local installations or generate new parameters or instability indices the temperature and specific humidity profiles can be written in binary files The main advantage is the spatial temporal and vertical collocation of these T q profiles allowing debugging activities vertical cross sections 3D visualizations and generation of validation datasets Examples on how to use the PGEI3 SPhR binary files to generate validation dataset can be found in the Validation Report AD 7 Examples on the use of the PGEI3 SPhR binary file in nowcasting can be found in Martinez 2009 In order to facilitate the use of the binary files tools to convert the PGEI3 SPhR binary files to netCDF format are being developed At the time being the IDL prototype is available FORTRAN or C version can be written using the API netCDF library using the IDL version as basis These conversion tools are being developed at the best effort basis There are several software packages that read the netCDF format and can be used by the users to a wider and deeper Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for I 12 Qe 208 ALMet SEVIRI Physical Retrieval 588 ee Product SPhR PGEI3 v1 2 File SAF NWC CDOP INM SCI PUM 13 v1 2 NWCSAF ee Page 16 33 exploitation of the PGEI3 SPhR binary files
49. the execution conditions users must look for a balance among the region size the machine performances and the following configurable keywords of the configuration file BT RMS THRESHOLD LSIZE FOR CSIZE FOR and MAX ITERATIONS see in section 4 3 1 for a wider discussion on how to choose them Code SAF NWC CDOP INM SCI PUM 13 Product User Manual for i 12 Bun es 2008 ALMet SEVIRI Physical Retrieval 588 ee File SAF NWC CDOP INM SCI PUM 13_v1 2 Page 21 33 NWCSAF enatis de Meesi Product SPhR PGEI3 v1 2 4 DESCRIPTION OF INPUTS COEFFICIENTS FILES AND CONFIGURABLE PARAMETERS In this section a description of the inputs coefficients files content and user configurable parameters is made Concerning the coefficients files more specific scientific information together with the description of the process to generate them can be found in the PGEI3 SPhR Algorithm Theoretical Basis Document AD 2 4 1 DESCRIPTION OF INPUTS FOR PGEI3 SPHR A region configuration file and a PGEI3 model configuration file with the diverse parameters and options that are indicated by the user for calculation see section 4 3 are needed as mandatory parameters in order to execute the PGE13 command Both must be located in the ssarnwc config directory 4 1 1 Region configuration file The region configuration file set the dimensions and positions where PGE13 SPhR product will be obtained as example france cfg that defines a region
50. ysical Retrieval ine A eo Product SPhR PGE13 v1 2 6 EXAMPLES OF PGE13 SPhR VISUALISATION Graphic displays of PGEI3 SPhR product parameters generated at the AEMET NWCSAF MSG Reference System area are available on real time in the web site of the NWC SAF Help Desk http www nwesaf org For the display of the clear air outputs a set of colour enhancement tables similar to the ones used by CIMSS for the visualisation of the GOES derived TPW and LI product has been selected See http cimss ssec wisc edu goes rt sounder dpi php The images corresponding to the 23 July 2009 at I2UTC are shown as an example in the figures bellow The images have been generated in near real time with NWC SAF PGEI3 SPhR v1 2 algorithm The region processed in these examples is 2200 elements x 1019 lines One of the best ways to exploit the water vapour and the thermal stability indices generated by PGEI3 SPhR software is to take advantage of the high spatial and temporal resolution of SEVIRI and to use loops of 1mages to monitor their evolution PGE13SPHR BL 23 TOL O9 AT lz Figure 5 Example of PGEI3 SPhR _BL from 12 UTC on 23 Jun 2009 19 produced p SEVIRI on MSG2 o BRFNHC PGE13 PGE1L13SPHR ML 23 JUL 09 AT ie Figure 6 Example of PGEI3 SPhR ML from 12 UTC on 23 Jur 2009 cq pem SEVIRI on MSG2 Product User Manual for Code SAF NWC CDOP INM SCI PUM 13 gt Ad Met SEVIRI Physical Retrieval Issue 1 2 Date 15 February 2012
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