Product User Manual for the “Convective Rainfall Rate
Contents
1. NWC SAF Agencia Estatal de Meteorologia Page r Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective ef Rainfall Rate CRR PGEOS v4 0 Issue 4 0 1 Date 4 December 2014 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 1 29 The EUMETSAT Network of Satellite Application Facilities Support to Nowcasting and Very Short Range Forecasting Product User Manual for the Convective Rainfall Rate CRR PGE05 v4 0 SAF NWC CDOP2 INM SCI PUM 05 Issue 4 Rev 0 1 4 December 2014 Applicable to SAFNWC MSG version 2013 Prepared by AEMET n Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Met Rainfall Rate CRR PGEOS v4 0 Issue 4 0 1 Date 4 December 2014 l l i File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Aencia Estatal de Meteorologia Page 2 29 REPORT SIGNATURE TABLE Antonio Rodr guez AEMET 4 December 2014 Prepared by Cecilia Marcos AEMET 4 December 2014 Reviewed by 4 December 2014 Authorised by Code SAF NWC CDOP2 INM SCI PUM 05 Issue 4 0 1 Date 4 December 2014 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 Page 3 29 Product User Manual for the Convective Met Rainfall Rate CRR PGE05 v4 0 NWC SAF Ancia Estatal de Meteorologia DOCUMENT CHANGE RECORD Version _ Date Pages CHANGES Doc code SAF NWC CDOP INM SCI PUM 05 2 March 2009 Initial version content derived fr2. 50 Table 3 CRR classes This output includes the following palette Amet NWC SAF Agencia Estatal de Meteorologia Product User Manual for the Convective Rainfall Rate CRR PGE05 v4 0 Code Issue File Page 14 29 SAF NWC CDOP2 INM SCI PUM 05 4 0 1 Date 4 December 2014 SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 CONVECTIVE RAINFALL RATE mm h 2 1 0 2 o SAFNWC PGEOS Figure 1 CRR palette CRR_ACCUM Rainfall rates from the images in the last hour are used in order to compute the hourly accumulations This output provides precipitation accumulations from 0 0 to 51 0 mm with a step of 0 2 mm and includes a palette that uses the same thresholds and colours as the classes output palette CRR_INTENSITY Rainfall rates in mm h are necessary to calculate the hourly accumulations This output provides rainfall rates from 0 0 to 51 0 mm h with a step of 0 2 mm h and includes a palette that uses the same colours as the classes output palette CRR_QUALITY 8 bits mask indicating which corrections have been applied for each pixel Moreover it indicates whether the product is latitude dependant or not and if the SEVIRI solar channel and the lightning information have been used during the computation of the CRR 1 bit for moisture correction 0 No correction 1 Corrected by PWHR factor 1 bit for cloud growth rate correction 0 No correction 1 Corrected by IR da
3. Algorithm Theoretical Basis Document for PGE05 AD 1 Default value 0 25 mm RAIN_LIGHTNING_RATE _4 Rain amount assigned to the pixels corresponding to the ZA area according to the lightning algorithm A detailed description of the lightning algorithm can be found in the Algorithm Theoretical Basis Document for PGE05 AD 1 Default value 0 10 mm COEFF_N_LIGHTNING_A Coefficient a of the equation that modifies the rain rate according to the density of lightning around each pixel in the lightning algorithm Default value 0 45 COEFF_N_LIGHTNING_B Coefficient b of the equation that modifies the rain rate according to the density of lightning around each pixel in the lightning algorithm Default value 0 7 Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 25 29 5 SUMMARY OF CONVECTIVE RAINFALL RATE CRR PRODUCT VALIDATION RESULTS The following tables summarize the validation results of this CRRv4 0 More details can be obtained from the Scientific report on improving NWCSAF MSG Precipitation Products AD 2 Green colour values in tables mean that FAR or POD values obtained in that validation fulfill the FAR and POD target values defined in the NWC SAF Product Requirements document AD 6 5 1 I
4. filled holes after parallax correction 0 No hole due to the parallax correction 1 Hole due to the parallax correction filled by a median filter 2 bits the hourly accumulation CRR band status 0 All required bands were available Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 16 29 1 One previous CRR band is missing 2 At least two previous CRR bands are missing no consecutive 3 At least two previous CRR bands are missing some are consecutive 1 bit for the status of the CRR pixels used to compute the hourly accumulation 0 All the pixels used in the computing of the hourly accumulation have their CRR_DATAFLAG bits set to 0 1 At least one of the pixels used in the computing of the hourly accumulation has at least one of its CRR_DATAFLAG bits set to 1 The HDF 5 output files are stored in s AFNWC export PGE0S Detailed information on the HDE 5 format file can be found in AD 4 Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 17 29 3 IMPLEMENTATION OF THE CONVECTIVE RAINFALL RATE CRR PRODUCT Previous co
5. pixel Orographic correction factor Local topography has long been recognised to have an effect on the distribution and intensity of precipitation However the rain induced by orographic forcing is a complex process associated with complicated flows Rainfall amounts are dependent on the atmospheric flow over the mountains and on the characteristics of the flow disturbances created by the mountains themselves This correction factor uses the interaction between the wind vector corresponding to 850 hPa level from the NWP and the local terrain height gradient in the wind direction to create a multiplier that enhances or diminishes the previous rainfall estimate as appropriate 2 2 3 Lightning algorithm As lightning activity is related with convection this information has been added to the product Only Cloud to Ground lightning flashes provided by ground based lightning detection networks are used by this algorithm To incorporate this information into the product a rain rate has been assigned to every lightning depending on the time distance At between the lightning event and scanning time of the processing region centre the location of the lightning the spatial density of lightning in a time interval Once the precipitation pattern has been computed it is compared to the CRR precipitation pattern in order to obtain the final product This final product contains the highest rain rate of the two The CRR lightning algor
6. pixel the next parameters are calculated CRR mm h basic values Quality and Data flags Fifth step develops those corrections that have been chosen to be applied using the output data from the previous step CRR mm h values Quality and Data flags are updated Sixth step computes rain rates from lightning information if this option has been chosen This data are combined with the output data from the previous step CRR mm h values Quality and Data flags are updated Last step converts the mm h CRR values into classes computes the hourly accumulations and writes the product outputs in SAFNWC format Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 19 29 4 INPUTS AND CONFIGURABLE PARAMETERS FOR CONVECTIVE RAINFALL RATE CRR PRODUCT 4 1 LIST OF INPUTS FOR CONVECTIVE RAINFALL RATE CRR 4 1 1 Convective Rainfall Rate CRR dynamic inputs Satellite imagery The following SEVIRI brightness temperatures and visible reflectances are needed at full IR spatial resolution T10 8um TPrevl0 8um T6 2um VISO 6um Mandatory Optional Mandatory Optional Table 4 CRR SEVIRI inputs The SEVIRI channels are input by the user in HRIT format and extracted on the desired region by SAFNWC software package These data must be located i
7. temperature at 2 m Temperature at 2 m Temperature at 1000 925 850 700 500 hPa Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 20 29 Surface Pressure For parallax correction Temperature at 1000 925 850 700 500 400 300 250 and 200 hPa Geopotential at 1000 925 850 700 500 400 300 250 and 200 hPa For orographic correction U and V wind components in 850 hPa Lightning information file for PGE05 A file with information on every lightning stroke occurred in a time interval is mandatory to choose the option of adjusting the CRPh precipitation pattern with the lightning information provided by ground based lightning detection networks Information about the Lightning information file for CRPh product structure can be found in the Interface Control Document AD 3 This file must be located in SAFNWC import Obs_data The CRR lightning algorithm and the coefficients applied have been derived for Spain using the lightning information from the AEMET lightning detection network Ground based lightning detection networks provide information with different performances in detection efficiency and location accuracy For this reason the keyword APPLY_LIGHTNING in the model configuration file is set to 0 and by default th
8. 0 1 NWC SAF Agencia Estatal de Meteorologia Page 22 29 temperature maximum Coefficient used when the Evolution Gradient Real 0 50 correction is applied When the previous IR image is not available and Gradient correction is applied this coefficient multiplies the previous computed CRR value if the analysed pixel has not a local IR temperature maximum or minimum Indicates if the SEVIRI solar channel has to be Integer 1 used in the computation of the CRR 1 yes 0 no Indicator whether the Lightning information Integer 0 should be used or not 1 yes 0 no Time interval to consider lightning data files Integer 15 Rain rate parameter 1 linked to observed Real 2 3 lightning Rain rate parameter 2 linked to observed Real 0 75 lightning Rain rate parameter 3 linked to observed Real 0 25 lightning Rain rate parameter 4 linked to observed Real 0 1 lightning Coefficient a to be applied during the Real 0 45 lightning adjustment function Coefficient b to be applied during the Real 0 7 lightning adjustment function Parameter Wind velocity u component ms Chain of NWP_UW characters sampling rate segment size 1 interpolation method BILIN Parameter Wind velocity v component ms Chain of NWP_VW characters sampling rate segment size 1 interpolation method BILIN Parameter Relative humidity Chain of NWP_PR j i characters samplin
9. 2 2 1 Processing of the Convective Rainfall Rate CRR n 10 222 Convective Rainfall Rate CRR correction factors osses 10 2 2 3 Behin A COMIN a a E 12 23 DESCRIPTION OF THE CONVECTIVE RAINFALL RATE CRR OUTPUTS cccsssccceessseeeeeesnees 13 3 IMPLEMENTATION OF THE CONVECTIVE RAINFALL RATE CRR PRODUCT17 3 4 INSTALLATION STEP FOR CONVECTIVE RAINFALL RATE CRR cccccceeeeessssceeeeeeeeeeenees I7 3 2 PREPARATION STEP FOR CONVECTIVE RAINFALL RATE CRR cccssccceessseeceesssseseesssseeees 17 3 3 EXECUTION STEP FOR CONVECTIVE RAINFALL RATE CRR cccssccesseeesseeesneeeeseeesseeenenes 17 4 INPUTS AND CONFIGURABLE PARAMETERS FOR CONVECTIVE RAINFALL RATE CRE PRODUC Dorcirencinitancn 19 4 1 LIST OF INPUTS FOR CONVECTIVE RAINFALL RATE CRR sssessssssssssssssserersssssserreesssssserreeess 19 4 1 1 Convective Rainfall Rate CRR dynamic inputs ccccccccccccccessecseceeseceeeseeeesseeenseeenes 19 4 1 2 Convective Rainfall Rate CRR static WPS aiceicteteisisininincteteeinccentneieins 20 4 2 LIST OF CONFIGURABLE PARAMETERS FOR CONVECTIVE RAINFALL RATE CRR 00005 Zk 4 2 1 Keywords table for Convective Rainfall Rate CRR oseese 21 4 2 2 Keywords description for Convective Rainfall Rate CRR n os 23 5 SUMMARY OF CONVECTIVE RAINFALL RATE CRR PRODUCT VALIDATION RESULTS svsccssscccssssasasesessssesssesesasscessscncsscscsasesesssccssscsassssvesssseensesasssscesssseessecasivcees 25 5 1 TST ART AINE OW Sh ATE
10. CT ASSUMPTIONS AND LIMITATIONS The CRR product is based on a calibration method which requires the availability of a training set of precipitation data derived from radar information to be used as ground truth to derive the relationship between satellite information and rainfall rate Regarding the radar data The drop size distribution used to obtain the radar rainfall rates mm h from the radar reflectivity Dbz has been assumed to be the Marshall Palmer type throughout the calibration and validation procedures No online operational method has been applied in order to adjust the radar rainfall intensities using rain gauge measurements Regarding the lightning algorithm The CRR lightning algorithm in CRR v4 0 and the coefficients applied have been derived for Spain using the lightning information from the AEMET lightning detection network Concerning this particular it is important to highlight that ground based lightning detection networks provide information with different performances in detection efficiency and location accuracy For this reason in the model configuration file the keyword APPLY_LIGHTNING is set to 0 and by default the lightning information is not used Before to use the lightning algorithm it is highly recommended to the user to adapt the coefficients to the specific performances of the lightning detection network serving that information This issue could be solved in a satisfactory manner in th
11. D 2 1 5 ACRONYMS ATBD CRR BALTRAD CSI EUMETSA FAR HRIT ICD INM IR MAE ME MSG NWCLIB OMSZ PC PGE POD PUM PWRH RAINSAT RMS RR SAF SAF NWC SEVIRI SUM SW Algorithm Theoretical Basis Document Convective Rainfall Rate Baltic Radar Network Critical Success Index T European Organisation for the Exploitation of Meteorological Satellites False Alarm Ratio High Rate Information Transmission Interface Control Document Instituto Nacional de Meteorolog a Infrared Mean Absolute Error Mean Error Meteosat Second Generation Nowcasting SAF Library Hungarian Meteorological Service Percentage of Corrects Product Generation Element Probability of Detection Product User Manual Moisture Correction Factor Rainfall Satellite Technique Root Mean Square error Rain Rate Satellite Application Facility Satellite Application Facility for Nowcasting Spinning Enhanced Visible and Infrared Imager Software User Manual Software Code SAF NWC CDOP2 INM SCI PUM 05 Issue 4 0 1 Date 4 December 2014 File SAF NWC CDOP2 INM SCI PUM 05_ v4 0 1 Page 9 29 Product User Manual for the Convective Met Rainfall Rate CRR PGE05 v4 0 NWC SAF Ancia Estatal de Meteorologia 2 V 2 Variable 3 V 3 Variable VIS Visible WV Water Vapour 1 6 REFERENCES 1 6 1 Applicable Documents For dated references subsequent amendments to or revisions of any of these publications do not apply For undated refe
12. NSTANTANEOUS RATES 5 1 1 Accuracy statistics Algorithm N Mean ME MAE RMSE mm h mm h mm h mm h 3 V function 846153 0 60 0 47 1 18 2 81 2 V function 868860 0 63 0 81 1 55 3 19 Table 6 Accuracy statistics for instantaneous rates 5 1 2 Categorical statistics Algorithm FAR POD CSI PC 3 V function 30 6 58 1 45 9 65 4 2 V function 44 6 54 4 37 8 55 1 Table 7 Categorical statistics for instantaneous rates 5 2 HOURLY ACCUMULATIONS 5 2 1 Accuracy statistics Algorithm N Mean ME MAE RMSE mm h mm h mm h mm h 3 V function 576334 0 39 0 38 0 79 1 99 2 V function 602462 0 41 0 54 0 97 2 15 Table 8 Accuracy statistics for hourly accumulations Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 s Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCE PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 26 29 5 2 2 Categorical statistics Algorithm FAR POD 0 CSI 0 PC 0 3 V function 49 0 63 8 39 3 63 9 2 V function 58 2 58 6 32 3 55 4 Table 9 Categorical statistics for hourly accumulations Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 27 29 6 CONVECTIVE RAINFALL RATE CRR PRODU
13. Page 29 29 1 SAFNHC PGEOS Figure 3 CRR hourly accumulations output corresponding to 25 May 2009 at 14 00Z
14. S E E E E eases saan saan asanegeesane E E S 25 Iad PEE E I N A NE E A E A 25 Whee CIRO TICE SIE STOW ospearen A AE AE eno ea Satna ASR AAAA 25 5 2 HOURLY ACCUMULA TIONS ceceo Adak A EE Erir EEn rie 25 5 2 1 Acura VdS Onana a N RNN 25 5 2 2 Cate POr COl NOU CSE E OA URE 26 6 CONVECTIVE RAINFALL RATE CRR PRODUCT ASSUMPTIONS AND LIMI FA TIONS stcavessiesupsescocszessesssessevsivassvasccssigcssssecesesesesdsusosesuassecusstacesetespsasssasussbesesteascsisaucsteiess 27 7 EXAMPLE OF CONVECTIVE RAINFALL RATE CRR PRODUCT VES UA TSTSA TOWN ic ssssusescossoseustopsevesssesccsvavenin sessoneusnaniesssseetusss ssctsuscesadsesssacessussscavsssestassesiacsasetsiees 28 7 1 1 TNSIGIMONCOUS ALE Siset fier E nce ee eee 28 ae be Hourly PC ONS soree EEEE EE EEE EE RAEE ENEE 28 AEMet Product User Manual for the Convective Rainfall Rate CRR PGE05 v4 0 Code Issue SAF NWC CDOP2 INM SCI PUM 05 4 0 1 Date 4 December 2014 i hE ve ie l a di a List of Tables and Figures Table 1 List ot Applicable D cUmeNtS en Er 9 Table 2 Bist of Reference D c Mm M Serrara ar rarer E E EE r E O E EE E e 9 Table 3 CRR Classes t2tsisicisisisisisiienaeesieiatsiaiabsiehstaleiadedd O A A EDE 13 Tabled CRR SE VIRIL MPU S aeieeiaii ieai a e i E ERa Ani a ERa ER Ra R ha hibai 19 Table 5 Model configuration file keywords table sssscossnscessrcncssssscicssrsscicssssssismerissossisseisisitaa 23 Table 6 Accuracy statistics for instantaneous rate
15. THRESHOLD Default value 3 mm h e APPLY_LIGHTNING To decide whether the lightning information will be used keyword set to 1 or not keyword set to 0 to combine the CRR precipitation pattern By default this keyword is set to 0 e LIGHTNING_DELTA_TIME Time interval before the scanning time of the processing region centre where the lightning occurrences will be taken into account by the lightning algorithm Default value 15 min e RAIN_LIGHTNING_RATE_1 Rain amount assigned to the pixels corresponding to the Zl area according to the lightning algorithm A detailed description of the lightning algorithm can be found in the Algorithm Theoretical Basis Document for PGEO5 AD 1 Default value 2 30 mm Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 AEMmet Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 24 29 RAIN_LIGHTNING_RATE_2 Rain amount assigned to the pixels corresponding to the Z2 area according to the lightning algorithm A detailed description of the lightning algorithm can be found in the Algorithm Theoretical Basis Document for PGE05 AD 1 Default value 0 75 mm RAIN_LIGHTNING_RATE_3 Rain amount assigned to the pixels corresponding to the Z3 area according to the lightning algorithm A detailed description of the lightning algorithm can be found in the
16. ace with the SAFNWC software architecture of each PGE 1 3 SOFTWARE VERSION IDENTIFICATION This document describes the algorithm implemented in the PGEOS version v4 0 of SAFNWC software package delivery 1 4 IMPROVEMENTS FROM PREVIOUS VERSION A change has been applied in the algorithm retrieval of rain rates without changing the physical base Calibration matrices have been substituted by analytical functions Also a tuning of the calibration analytical functions has been done against radar data For this purpose radar data from BALTRAD Spanish and Hungarian radar networks have been used Modification in the outputs NWC SAF Agencia Estatal de Meteorologia Issue 4 0 1 Date 4 December 2 Product User Manual for the Convective Met Rainfall Rate CRR PGE05 v4 0 Page Code SAF NWC CDOP2 INM SCI PUM 05 014 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 8 29 The o Anew class has been included in the CRR Classes output The interval of this new class is from 0 2 to 1 mm h The colour palette has been modified accordingly o The CRR hourly accumulations output provides precipitation accumulations from 0 0 to 51 0 mm with a step of 0 2 mm The colour palette of this output has been modified to include values from 0 2 mm o The CRR intensities output provides rainfall rates from 0 0 to 51 0 mm h with a step of 0 2 mm h and includes a colour palette improvements are shown in the Validation Report A
17. ction factor also designated as gradient correction factor is based on a search of the highest coldest and lowest less cold cloud tops The idea is to search for the pixels that are below the average cloud top surface temperature local temperature minima and assume these pixels indicate active convection associated with precipitation beneath The hessian of the temperature field is analysed for each pixel with a temperature lower than 250K in order to search for those pixels with extreme values as is explained in the Algorithm Theoretical Basis Document AD 1 Rain rate corresponding to those pixels which have a maximum meaning that are warmer than its surroundings is modified by multiplying a coefficient The value of that coefficient can be selected by the user through the keyword COEFF _EVOL_GRAD_CORR_01 in the model configuration file Default value 0 25 In those pixels which have neither a local IR temperature maximum nor minimum the rain rate is modified through a coefficient controlled by the keyword COEFF_EVOL_GRAD_CORR_02 Default value 0 50 Otherwise rain rate is not modified Parallax correction To apply the orographic correction factor is necessary to know the exact cloud position with respect to the ground below This is not a problem when a cloud is located directly below the satellite however as one looks away from the sub satellite point the cloud top appears to be farther away from the satellite than the clou
18. d base This effect increases as you get closer to the limb and as clouds get higher The parallax correction depends on three factors a the cloud height b the apparent position on the earth of that cloud and c the position of the satellite Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 12 29 The last two factors are known but the first one has to be estimated Two height estimation methods have been studied numerical model and climatological profile obtained from the 1962 standard atmosphere model Both of them are based on the conversion of each IR10 8 brightness temperature to height By default height is estimated using NWP data When the Parallax Correction is working a spatial shift is applied to every pixel with precipitation according to the basic CRR value If in this re mapping process two pixels of the original image are assigned to the same pixel of the final image the algorithm takes the maximum value of the rainfall rate and if a pixel of the final image is not associated to any pixel of the original image a hole appears in the final image the software identifies the pixels with hole and assigns to them a value of the rainfall rate that is the result of applying a 3x3 median filter centred on the hole
19. e further develop and maintain software packages to be used for Nowcasting applications of operational meteorological satellite data by National Meteorological Services More information can be found at the NWC SAF webpage http www nwcsaf org This document is applicable to the NWC SAF processing package for Meteosat satellites SAFNWC MSG 1 1 SCOPE OF THE DOCUMENT This document is the Product User Manual PUM for the MSG product PGE05 CRR and contains practical information on the characteristics of the product including the input data and the output product It also gives information about the algorithm s implementation and configuration 1 2 SCOPE OF OTHER DOCUMENTS The Algorithm Theoretical Basis Document contains information about the product objectives the algorithm scientific description the needed input data and the output product AD 1 The Validation Report version v1 0 of the PGEOS document AD 2 showing the validation results for PGE05 v4 0 that gives information about the extended validation performed over Spain for a complete year The Interface Control Documents ICD 1 AD 3 describes the External and Internal Interfaces of the SAFNWC MSG software The Interface Control Documents ICD 3 AD 4 defines the format of the output products generated by the SAFNWC MSG software The Architectural Design Document AD 5 presents the general architecture of the SAFNWC software and gives details on each PGE interf
20. e future with the use of lightning information provided by MTG Lightning Imager which will be able to provide lightning information with uniform and controlled performances all around the coverage area As a summary according to the feedback of the users the CRR product provides useful information as a complement to Radar products allowing the forecasters to identify convective areas Product User Manual for the Convective Met Rainfall Rate CRR PGE05 v4 0 NWC SAF Agencia Estatal de Meteorologia Code Issue File Page 28 29 SAF NWC CDOP2 INM SCI PUM 05 4 0 1 Date 4 December 2014 SAF NWC CDOP2 INM SCI PUM 05_ v4 0 1 7 EXAMPLE OF CONVECTIVE RAINFALL RATE CRR PRODUCT VISUALISATION 7 1 1 Instantaneous Rates Below is shown an image corresponding to CRR classes output It has been obtained at full resolution and all corrections have been applied CONVECTIVE RAINFALL RATE inmh Figure 2 CRR instantaneous intensities output corresponding to 25 May 2009 at 14 00Z 7 1 2 Hourly Accumulations Below is shown an image corresponding to CRR hourly accumulations output It has been obtained at full resolution and all corrections have been applied Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia
21. e lightning information is not used Before to use the lightning algorithm it is highly recommended to the user to adapt the lightning coefficients to the specific performances of the used lightning detection network through the appropriate keywords in the model configuration file 4 1 2 Convective Rainfall Rate CRR static inputs The following information is included or computed by the software package Sun angles associated to SEVIRI imagery This information is mandatory for normalising the VIS image when the solar channel is used It is computed by the CRR software itself using the definition of the region and the satellite characteristics Ancillary data sets Saturation Vapour table is mandatory for Humidity correction and is located in the SAFNWC import Aux_data PGEO05 directory Saturation Vapour Polynomial Coefficients table is mandatory for Humidity correction and is located in the s AFNWC import Aux_data PGE05 directory Climatological profile is necessary as a back up for Parallax correction in case NWP is not available This information is located in the SAFNWC import Aux_data PGE05 directory Elevation mask is mandatory for orographic correction and is located in the SAFNWC import Aux_data TOPO directory Model configuration file for PGEOS5 The CRR model configuration file located in the sAFNWC config directory contains configurable system parameters in the product generation process related with algorithm t
22. e way the product is going to be run choosing options such as the type of calibration or the corrections to be used In order to apply some corrections NWP data Convective Rainfall Rate CRR dynamic inputs have to be available in s AFNWC import NWP_data directory In order to use the lightning information the Lightning information file for PGEQO5 Convective Rainfall Rate CRR dynamic inputs have to be available in SAFNWC import Obs_data directory 3 3 EXECUTION STEP FOR CONVECTIVE RAINFALL RATE CRR The execution step is the real time process of the SEVIRI images over the region This process consists of the launch of the command PGEOS5 along with the required parameters slot region configuration file name and model configuration file name PGE05 requires mainly six steps First step consists of an initialisation which performs the environment settings for a given region and the Day Night mask for all the pixels processed Second step is intended to read the external data as SEVIRI bands Third step is to normalise the VIS image in case the solar channel is used Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 18 29 Fourth step holds the core process for the computation of the CRR product For each
23. ember 2014 l I i File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Ancia Estatal de Meteorologia Page 4 29 4 December 2014 Update of the information about NWP data needed for the running of CRR algorithm Code SAF NWC CDOP2 INM SCI PUM 05 Issue 4 0 1 Date 4 December 2014 Product User Manual for the Convective Met File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 Rainfall Rate CRR PGE05 v4 0 NWC SAF Agencia Estatal de Meteorologia Page 5 29 Table of contents Te INITRODUCTION ssiccacecesecasscecesscecscctaapsssatesatacesensssassoncnaasasansnsasasasansasasnonsnsnnesasenasoasseanasvasnanans 7 1 1 SCOPE OF THE DOCUMENT erresto re err rE EER IEE a areas aie ee 7 1 2 SCOPE OF OTHER DOCUMENTS nrnntinnnnnnnnn n ri n E nnn T 1 3 SOFTWARE VERSION IDENTIFICATION isssscsssuscssstecsksasdeastecsseassentcacansnsssesaansteastsastenttasssiastentceens 7 1 4 IMPROVEMENTS FROM PREVIOUS VERSION jsssssissssesssesessonsancssansessansann0esaesessonbessoneseaseseoonnes000 7 1 5 ACRONYM Sroeepo reor RERNE ETTE 8 1 6 REFERENCON ee Re ee E 9 1 6 1 Applicable Documents oen ena aR N N N NENN RRENEN ANGIR NEEN 9 1 6 2 Reference Docters norrir nna an a N A 9 2 DESCRIPTION OF THE CONVECTIVE RAINFALL RATE CRR PRODUCT 10 2 1 GOAL OF THE CONVECTIVE RAINFALL RATE CRR PRODUCT cccssscceeessseeeeessseeeeessnseeees 10 2 2 ALGORITM OUTLINE OF CONVECTIVE RAINFALL RATE CRR cccssccceesssseceesssseseeessseeees 10
24. f the cloud tops the amount of moisture available to produce rain and the influence of orographic effects on the precipitation distribution several correction factors can be applied to the basic CRR value by the users So that the possible correction factors are the moisture correction the cloud top growth decaying rates or evolution correction the cloud top temperature gradient correction the parallax correction and the orographic correction At this stage the CRR precipitation pattern computed in the previous step is combined with a precipitation pattern derived through a lightning algorithm At the end of the process the final values of the CRR rainfall rates are used in order to obtain five different outputs as described in section 2 3 2 2 2 Convective Rainfall Rate CRR correction factors Moisture Correction Factor Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 11 29 When thunderstorms take place in quite moist environments the computed rainfall rate should be greater than when they occur in dry air masses To consider this effect a moisture correction factor has been developed It adjusts the estimates when the air is dry or quite moist This factor has been defined as the product of the total precipitable water PW in t
25. g rate segment size 1 interpolation method BILIN Parameter 2m dewpoint temperature K NWP_2D sampling rate segment size leh of 1 j characters interpolation method BILIN Parameter 2m air temperature K NWP_PT ies Chain of sampling rate segment size characters 1 interpolation method BILIN Parameter Temperature K NWP_PT Marat 5 Chain of sampling rate segment size charters 1 interpolation method BILIN Parameter Surface pressure Pa NWP_SP sampling rate segment size pha of 1 pog iors characters interpolation method BILIN Parameter Geopotential m s Chain of NWP_GEOP sampling rate segment size characters 1 Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_ v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 23 29 interpolation method BILIN Table 5 Model configuration file keywords table 4 2 2 Keywords description for Convective Rainfall Rate CRR Below there is a description of the most useful keywords defined in PGEO5 model configuration file in order to make easier the user exploitation e DAY_NIGHT_ZEN_THRESHOLD to choose the solar zenith angle that selects between 2 V and 3 V Calibrations By default this keyword is set to 80 e USE_SOLAR_CHANNEL to choose whether the Software will use the solar channel
26. he layer from surface to 500 hPa by the relative humidity RH mean value between surface and 500 hPa level obtained from a numerical model An environment is considered to be dry if PWRH is significantly below 1 0 and quite moist if PWRH is greater than 1 0 The PWRH factor decreases rainfall rates in very dry environments and increases them in very moist ones Cloud Growth Rate Correction Factor Convective rain is assumed to be associated with growing clouds exhibiting overshooting tops Consecutive satellite IR images are used to indicate vertically growing and decaying cloud systems The cloud growth correction factor also designated as evolution correction factor only changes the magnitude of the rain rate through a coefficient if the analysed pixel becomes warmer in the second image The coefficient value can be modified by the user through the keyword COEFF_EVOL_GRAD_CORR_00 in the model configuration file Default value for Normal Mode 0 35 is set in the configuration file Recommended value for Rapid Scan mode is 0 55 The cloud growth rate correction factor can not be applied when consecutive images are not available In this case the alternative method of Cloud top Temperature Gradient Correction is applied Cloud top Temperature Gradient Correction Factor This alternative correction method is based on the fact that much information can be extracted from the cloud top structure on a single IR image This corre
27. hresholds ancillary datasets numerical model data corrections to be applied etc The complete Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 21 29 list of these parameters and the explanation of the most useful ones is available on List of configurable parameters of this manual and in the Interface Control Document AD 3 4 2 LIST OF CONFIGURABLE PARAMETERS FOR CONVECTIVE RAINFALL RATE CRR Model configuration file contains configurable items in the product generation process such as algorithm thresholds SEVIRI channels to be used by the PGE coefficients etc The CRR model configuration file needed for the execution of PGEO5 must be placed at the SAFNWC config directory The only constraint in the use of any name is the key used to specify the parameters to be used from NWP models NWP_PARAM The use of this keyname is mandatory and will be used by a pre processing task in charge of remapping NWP incoming files in GRIB format 4 2 1 Keywords table for Convective Rainfall Rate CRR The CRR model configuration file contains the following information Keyword Description Type Default Value s Identifier of the PGE Chain of PGE05 characters SEVIRI channels to be used by PGE05 Chain of VISO6 WV62 IR108 charac
28. ithm and the coefficients applied have been derived for Spain using the lightning information from the AEMET lightning detection network Ground based lightning detection networks provide information with different performances in detection efficiency and location accuracy For this reason the keyword APPLY_LIGHTNING in the model configuration file is set to O and by default the lightning information is not used Before to use the lightning algorithm it is highly recommended to the user to adapt the lightning coefficients to the specific performances of the used lightning detection network through the appropriate keywords in the model configuration file Product User Manual for the Convective p Met Rainfall Rate CRR PGE05 v4 0 NWC SAF Agencia Estatal de Meteorologia Code Issue File Page 13 29 SAF NWC CDOP2 INM SCI PUM 05 4 0 1 Date 4 December 2014 SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 2 3 DESCRIPTION OF THE CONVECTIVE RAINFALL RATE CRR OUTPUTS CRR product is coded in HDF5 format The available outputs are the following CRR The rainfall rates obtained by the CRR algorithm expressed in mm h are converted into twelve classes as it is shown bellow CLASSES RAINFALL RATE mm h 0 rate lt 0 2 1 0 2 rate lt 1 2 1 rate lt 2 3 2 rate lt 3 4 3 rate lt 5 5 5 rate lt 7 6 7 rate lt 10 7 10 rate lt 15 8 15 rate lt 20 9 20 rate lt 30 10 30 rate lt 50 11 rate 2
29. n the SAFNWC import SEVIRI_data directory Tf TPrev10 8um is not available the Cloud Growth Rate Correction Factor can not be computed but the Cloud top Temperature Gradient Correction Factor is computed instead as an alternative Numerical model The NWP files must be located in SAFNWC import NWP_data directory In real time operational mode 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 SAFNWC 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 NWP information is used by default for parallax correction In case of lack of NWP parameters parallax correction will be run using a climatological profile NWP information is mandatory for moisture and orographic corrections When this information is not available CRR is computed without applying these two corrections There are no studies on the impact of NWP data horizontal and temporal resolutions on estimated rain rates throughout those corrections at this time Some studies are expected to be done in this line for the future NWP vertical resolution required by the corrections is the following For moisture correction Relative Humidity at 1000 925 850 700 and 500 hPa Dew Point
30. ndition and licences The right to use copy or modify this software is in accordance with EUMETSAT Policy for the SAFNWC MSG software package 3 1 INSTALLATION STEP FOR CONVECTIVE RAINFALL RATE CRR The software installation procedure does not require special resources It is restricted to decompress the distribution file a gz compressed tar file and to successfully build the executable PGEQ05 file to be stored into the SAFNWC bin directory Once the PGEO5 of the SAFNWC MSG is installed and configured in the system its operational use requires the definition of some Configuration files in order to select the regions to be processed and some needed configurable parameters The automatic set of pre defined time scheduling of the preparation step is in Programmed Task Definition Files 3 2 PREPARATION STEP FOR CONVECTIVE RAINFALL RATE CRR The configuration file in charge of the region where the product is going to be run has an optional name and the cfg extension This file contains the region centre location and the size image When the application is installed some region configuration files appear in SAFNWC config Each of them corresponds to a different region nevertheless users can create their own region configuration file The configuration file in charge of the product settings is the PGEOS model configuration file that has an optional name and the cfm extension Through this file the user can configure th
31. om Software User Manual for PGEO5 Convective Rainfall Rate of the SAFNWC MSG scientific part Indications and recommendations given by the DRI MSG 2009 have been included 11 May 2010 Document updated for the SAFNWC MSG PGE05 v3 1 CRR rain rate algorithm retrieval updated to work using lightning data information SPR 374 SMR 352 1 April 2011 Minor changes done according to action MSG DRI2010 10 No scientific updates adapted date issue and rev to v2011 15 February 2012 Minor changes done according to SPR 485 SMR 457 No scientific updates adapted date issue and rev to v2012 4 December 2014 Modifications for PGE05 v4 0 e Calibration matrices have been substituted by analytical functions A tuning of the calibration analytical functions has been done The CRR classes output includes a new class and colour palette The CRR hourly accumulations output provides precipitation accumulations from 0 0 to 51 0 mm with a step of 0 2 mm and includes a new colour palette The CRR intensity in mm h output provides rain rates from 0 0 to 51 0 mm h with a step of 0 2 mm h and includes a new colour palette Modification of ComputeAccum c related to SPR 505 SMR 480 Indications and recommendations given by the NWC SAF SW Package MSG 2013 DRR have been included a Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Met Rainfall Rate CRR PGEOS v4 0 Issue 4 0 1 Date 4 Dec
32. only for day time or not By default this keyword is set to 1 the solar channel is going to be used e COEFF EVOL_GRAD_CORR_00 When two consecutives IR images are available and the Evolution correction is applied if in a pixel the IR brightness temperature increases the CRR value computed in that pixel is multiplied by this coefficient Default value for Normal Mode 0 35 is set in the configuration file Recommended value for Rapid Scan mode is 0 55 e COEFF_EVOL_GRAD_CORR_01 When the previous IR image is not available and the Gradient correction is working this coefficient multiplies the initial CRR value if the analysed pixel has a local IR temperature maximum Default value 0 25 e COEFF EVOL_GRAD_CORR_02 When the previous IR image is not available and the Gradient correction is working this coefficient multiplies the initial CRR value if the analysed pixel has neither a local IR temperature maximum nor minimum Default value 0 50 e WIN_FILTER_SEMISIZE The obtained basic CRR data are set to zero if all the pixels in a grid with a WIN_FILTER_SEMISIZE pixels semisize default value 3pix centred on the pixel have a value lower than a selected threshold The size of this window will be WIN_FILTER_SEMISIZE 2 1 x WIN_FILTER_SEMISIZE 2 1 e FILTER_THRESHOLD The basic CRR data obtained from the functions are set to zero if all the pixels in the selected window filter centred on the pixel have a value lower than FILTER_
33. rences the current edition of the document referred applies Reference Title Code Vers Date AD 1 Algorithm Theoretical Basis SAF NWC CDOP2 INM SCI 4 0 15 07 13 Document for Convective ATBD 05 Rainfall Rate CRR PGEO5 v4 0 AD 2 Validation Report for Convective SAF NWC CDOP2 INM SCI 1 0 15 07 13 Rainfall Rate CRR PGEO05 VR 12 v4 0 AD 3 Interface Control Document for the SAF NWC CDOP2 INM SW I 7 0 15 07 13 External and Internal Interfaces CD 1 of the SAFNWC MSG AD 4 SAFNWC MSG Output Products SAF NWC CDOP2 INM SW I 7 0 15 07 13 Format Definition CD 3 AD 5 Architectural Design Document for SAF NWC CDOP2 INM SW 7 0 15 07 13 the AEMET related PGEs of AD 4 the SAFNWC MSG AD 6 NWC SAF Product Requirements NWC CDOP2 SAF AEMET 1 2 15 07 13 Document MGT PRD Table 1 List of Applicable Documents 1 6 2 Reference Documents ep upp Table 2 List of Reference Documents Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 10 29 2 DESCRIPTION OF THE CONVECTIVE RAINFALL RATE CRR PRODUCT 2 1 GOAL OF THE CONVECTIVE RAINFALL RATE CRR PRODUCT The CRR algorithm developed within the SAF NWC context estimates rainfall rates from convective sy
34. s cccceeescceesceeseceeseeeeseeeeseeeeeseeceeseeesseeeeeseees 25 Table 7 Categorical statistics for instantaneous rates s sesesesesesessresseessesesreesseressreesstessressreesee 25 Table 8 Accuracy statistics for hourly accumulations ssesseesseessessseeessresressessrestsssessrsseesersseses 25 Table 9 Categorical statistics for hourly accumulations ccccecescceeseceesneeeeseeeeeeeeesseeeeseeeeeseees 26 Figure 1 CRR i ilo Caer een ee ents er tr eeateT breve err tree try eres reve este tsar es ert ver ty tety esters er trer feet ai hakai errr tree 14 Figure 2 CRR instantaneous intensities output corresponding to 25 May 2009 at 14 00Z 28 Figure 3 CRR hourly accumulations output corresponding to 25 May 2009 at 14 00Z 29 Code SAF NWC CDOP2 INM SCI PUM 05 Issue 4 0 1 Date 4 December 2014 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 Page 7129 Product User Manual for the Convective Met Rainfall Rate CRR PGE05 v4 0 NWC SAF Agencia Estatal de Meteorolog a 1 INTRODUCTION The EUMETSAT Satellite Application Facilities SAF are dedicated centres of excellence for processing satellite data and form an integral part of the distributed EUMETSAT Application Ground Segment http www eumetsat int This documentation is provided by the SAF on Support to Nowcasting and Very Short Range Forecasting NWC SAF The main objective of NWC SAF is to provid
35. stems using IR WV and VIS MSG SEVIRI channels and calibration analytical functions generated from both SEVIRI and Radar data This product can be obtained for every SEVIRI slot that is every 15 minutes in the normal mode It is also prepared to run in the Rapid Scan mode with a temporal resolution of 5 minutes 2 2 ALGORITM OUTLINE OF CONVECTIVE RAINFALL RATE CRR 2 2 1 Processing of the Convective Rainfall Rate CRR The basic CRR mm h value for each pixel is obtained from calibration analytical functions Calibration analytical functions are generated by combaining SEVIRI and Radar data Composite radar data are compared pixel by pixel with geographically matched MSG data in the same resolution and the rainfall rate RR is obtained as a function of two or three variables IR brightness temperature IR WV brightness temperature differences and normalised VIS reflectances RR f IR IR WV VIS for 3 V calibration RR f IR IR WV for 2 V calibration A filtering process is performed in order to eliminate stratiform rain data which are not associated to convective clouds the obtained basic CRR data are set to zero if all the pixels in a grid of a selected semisize def value 3pix centred on the pixel have a value lower than a selected threshold def value 3mm h The threshold and the size of the grid can be modified by the user through the model configuration file To take into account the temporal and spatial variability o
36. ta from previous slot Code SAF NWC CDOP2 INM SCI PUM 05 Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4 0 1 NWC SAF Agencia Estatal de Meteorologia Page 15 29 1 bit for cloud top temperature correction 0 No correction 1 Corrected by IR temperature gradient 1 bit for parallax correction 0 No correction 1 Corrected by parallax 1 bit for orographic effect correction 0 No correction 1 Corrected by orographic effects 1 bit for latitude dependant set always to since dependency on latitude is always taken into account 1 bit for solar channel used 0 No solar channel used 1 Solar channel used 1 bit for lightning information used 0 No lightning information used 1 Lightning information used CRR_DATAFLAG 8 bits mask indicating the processing status of each pixel 1 bit for IR10 8 WV6 2 or VISO 6 data missing 0 All the channel data required are available 1 There is a missing data in some channel 1 bit to indicate if the set of SEVIRI data is out of the calibration matrices range set always to 0 since calibration matrices are not used 1 bit to identify mathematical errors 0 No mathematical error 1 A mathematical error has occurred 1 bit for the convective filter 0 The CRR value remains the same 1 The CRR value has been set to zero because of the filtering process 1 bit for the
37. ters Solar zenith angle to select between day and Double 80 night cases in degrees Semi size of the window used to filter the Basic Integer 3 CRR image in pixels Window_Size 2 WIN_FILTER_SEMISIZE 1 2 WIN_FILTER_SEMISIZE 1 Threshold for filtering process Integer 3 Indicator whether the Humidity correction Integer 1 should be applied or not 1 yes 0 no Indicator whether the Evolution Gradient Integer 1 correction should be applied or not 1 yes 0 no Indicator whether the Parallax correction should Integer 1 be applied or not 1 yes 0 no Indicator whether the Orographic correction Integer 1 should be applied or not 1 yes 0 no Coefficient used when the Evolution Gradient Real 0 35 correction is applied When two consecutives IR images are available and the Evolution correction is applied if in a pixel the IR brightness temperature increases the CRR value computed in that pixel is multiplied by this coefficient Coefficient used when the Evolution Gradient Real 0 25 correction is applied When the previous IR image is not available and the Gradient correction is applied this coefficient multiplies the previous computed CRR value if the analysed pixel has a local IR Code SAF NWC CDOP2 INM SCI PUM 05 gt Product User Manual for the Convective Issue 4 0 1 Date 4 December 2014 N A a Met Rainfall Rate CRR PGE05 v4 0 File SAF NWC CDOP2 INM SCI PUM 05_v4
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