Product User Manual for Land Surface Albedo

Transcription

1 Product User Manual for Land Surface Albedo PRODUCTS: LSA- (MDAL), LSA-2 (MTAL), LSA-5 (MTAL-R), LSA-3 (ETAL) Reference Number: Issue/Revision Index: LAST CHANGE: SAF/LAND/MF/ATBD_LSA/. Issue 4 8//28

2 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 DOCUMENT SIGNATURE TABLE Name Prepared by: Météo-France / CNRM Dominique Carrer 8//28 Approved by: Land SAF Project Manager 8//28 DOCUMENTATION CHANGE RECORD Issue / Revision Version. Version. Version. Version.2 Version.3 Version.4 Version.5 Version.6 Version.7 Version.8 Date 29//24 2//24 8/3/25 /6/25 2//26 9//26 9/3/2 5/2/22 5/2/25 /6/26 Description: Preliminary version Version prepared for SIVVRR 2 Version prepared for Check-Point Meeting Version prepared for ORR- Version prepared for ORR- Close-Out Version prepared for OR- Version prepared for ORR-A Version prepared for ORR Close-out Version prepared for New Processing Chain Version prepared for ORR of the LSA System I - EPS and EPS Products Version.9 25//26 Version. 8//28 Version updated from ORR of the LSA System I - EPS and EPS Products Added MTAL-R CDR (LSA-5), corrected bug bit 7 (table albedo quality flag) 2

3 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 TABLE OF CONTENTS INTRODUCTION PRODUCT DESCRIPTION Overview Product dissemination Geolocation / Rectification File Formats Product Content Summary of Product Characteristics... 8 APPENDIX A DEVELOPERS... 2 APPENDIX B GLOSSARY...2 APPENDIX C HDF5-ATTRIBUTES

4 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 LIST OF FIGURES Figure : The LSA SAF geographical areas for SEVIRI-based products.... Figure 2: Examples of MTAL-R broadband albedo products for January 5, 22, etc...5 Figure 3: Colour composite image derived from the three spectral directionalhemispherical SEVIRI-based albedo estimates for the st of December Figure 4: Colour composite image derived from the three spectral directionalhemispherical AVHRR-based albedo estimates for the 5th of May 25 of the ETAL product (R=.6μm, G=.8μm and B=.6μm)

5 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 LIST OF TABLES Table : The LSA SAF Set of Products and respective sensors and platforms. The table covers both existing and future EUMETSAT satellites, and therefore refers to operational products and development activities...7 Table 2: Series of MSG satellites considered for product achievement...8 Table 3: Series of Metop satellites considered for product achievement...8 Table 4: Satellite application Facility for Land Surface Analysis (LSA SAF) Meteosat Second Generation (MSG)-based and EPS Meteorological Operation (MetOp)-based surface albedo products characteristics...9 Table 5: Characteristics of the LSA SAF geographic windows... Table 6: Content of the broadband surface albedo product files, which is common to MDAL, MTAL, MTAL-R and ETAL...4 Table 7: Content of the spectral surface albedo product files for each channel β...6 Table 8: Albedo product quality flag information... 7 Table C: General HDF5 attributes for AL SEVIRI...2 Table C2: The attributes for each dataset of the HDF5-files for AL SEVIRI are described in the following table...24 Table C3: General HDF5 attributes for AL AVHRR...25 Table C4: The attributes for each dataset of the HDF5-files for AL AVHRR are described in the following table

6 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Introduction The Satellite Application Facility (SAF) on Land Surface Analysis (LSA) is part of the SAF Network, a set of specialised development and processing centres, serving as EUMETSAT (European organization for the Exploitation of Meteorological Satellites) distributed Applications Ground Segment. The SAF network complements the product-oriented activities at the EUMETSAT Central Facility in Darmstadt. The main purpose of the LSA SAF is to take full advantage of remotely sensed data, particularly those available from EUMETSAT sensors, to measure land surface variables, which will find primarily applications in meteorology (lsa-saf.eumetsat.int). The spin-stabilised Meteosat Second Generation (MSG) has an imagingrepeat cycle of 5 minutes. The Spinning Enhanced Visible and Infrared Imager (SEVIRI) radiometer embarked on the MSG platform encompasses unique spectral characteristics and accuracy, with a 3 km resolution (sampling distance) at nadir (km for the high-resolution visible channel), and 2 spectral channels (Schmetz et al., 22). The EUMETSAT Polar System (EPS) Metop-A (B and C) are Europe s first polar orbiting operational meteorological satellites and the European contribution to a joint polar system with the U.S. EUMETSAT will have the operational responsibility for the morning orbit with Meteorological-Operational (Metop) satellites, the first of which was successfully launched on October 9, 26. Despite the wide range of sensors on-board Metop ( most LSA SAF parameters make use of the Advanced Very High Resolution Radiometer (AVHRR) and, to a lesser extent, of the Advanced Scatterometer (ASCAT). Several studies have stressed the role of land surface processes on weather forecasting and climate modelling (e.g., Dickinson et al., 983; Mitchell et al., 24; Ferranti and Viterbo, 26). The LSA SAF has been especially designed to serve the needs of the meteorological community, particularly Numerical Weather Prediction (NWP). However, there is no doubt that the LSA SAF addresses a much broader community, which includes users from: Weather forecasting and climate modelling, requiring detailed information on the nature and properties of land. Environmental management and land use, needing information on land cover type and land cover changes (e.g. provided by biophysical parameters or thermal characteristics). Agricultural and Forestry applications, requiring incoming/outgoing radiation and vegetation properties. Renewable energy resources assessment, particularly biomass, depending on biophysical parameters, and solar energy. Natural hazards management, requiring frequent observations of terrestrial surfaces in both the solar and thermal bands. Climatological applications and climate change detection, requiring long and homogeneous time-series. information on 6

7 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Table - The LSA SAF Set of Products and respective sensors and platforms. The table covers both existing and future EUMETSAT satellites, and therefore refers to operational products and development activities. Product Family Product Group Sensors/Platforms Radiation Land Surface Temperature (LST) SEVIRI/MSG, AVHRR/Metop, FCI/MTG, VII/EPS-SG SEVIRI/MSG, FCI/MTG (internal product for other sensors) SEVIRI/MSG, AVHRR/Metop, FCI/MTG, VII/EPS-SG, 3MI/EPS-SG SEVIRI/MSG, FCI/MTG Land Surface Emissivity (EM) Land Surface Albedo (AL) Vegetation Down-welling Short-wave Fluxes (DSSF) Down-welling Long-wave Fluxes (DSLF) Normalized Difference Vegetation Index (NDVI) Fraction of Vegetation Cover (FVC) Leaf Area Index (LAI) Energy Fluxes Wild Fires Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) Gross Primary Production (GPP) Canopy Water Content (CWC) Evapotranspiration (ET) Reference Evapotranspiration (ET) Surface Energy Fluxes: Latent and Sensible (LE&H) Fire Detection and Monitoring (FD&M) Fire Radiative Power Fire Radiative Energy and Emissions (FRE) Fire Risk Map (FRM) Burnt Area (BA) SEVIRI/MSG, FCI/MTG AVHRR/Metop, VII/EPS-SG SEVIRI/MSG, AVHRR/Metop, FCI/MTG, VII/EPS-SG, 3MI/EPS-SG SEVIRI/MSG, AVHRR/Metop, FCI/MTG, VII/EPS-SG, 3MI/EPS-SG SEVIRI/MSG, AVHRR/Metop, FCI/MTG, VII/EPS-SG, 3MI/EPS-SG SEVIRI/MSG, FCI/MTG AVHRR/Metop, VII/EPS-SG SEVIRI/MSG, FCI/MTG SEVIRI/MSG, FCI/MTG SEVIRI/MSG, FCI/MTG SEVIRI/MSG SEVIRI/MSG, FCI/MTG, VII/EPS-SG SEVIRI/MSG, FCI/MTG, VII/EPS-SG SEVIRI/MSG, FCI/MTG AVHRR/Metop, VII/EPS-SG The LSA SAF products (Table ) are based on level.5 SEVIRI/Meteosat and/or level b Metop data. Forecasts provided by the European Centre for Mediumrange Weather Forecasts (ECMWF) are also used as ancillary data for atmospheric correction. Table 2 & 3 below detail the evolution of the MSG and MetOP platforms, respectively, during the lifetime of the LSA SAF project. 7

8 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Table 2 - Series of MSG satellites considered for product achievement. (*) MSG- MSG-2 MSG-3 MSG-4 Period 9//24 23/9/26 25/9/26 2//23 (*) 22//23 2/2/28 (**) Since 2/2/28 Operated changes Calibration Band factors Calibration Band factors Calibration Band factors Calibration Band factors During this period MSG- took over as the prime satellite for short periods during the outages of MSG-2. (**) During this period both MSG-2 and MSG- took over as the prime satellites for short periods during the outages of MSG3 (e.g. for sensor decontamination). Table 3 - Series of MetOP satellites considered for product achievement. MetOP-A MetOP-B MetOP-C Period Not produced yet Since //25 Not yet available Operated changes Calibration Band factors Calibration Band factors Calibration Band factors 8

9 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 2 Product description 2. Overview In the LSA SAF operational system, the data processing exploits the full geographic coverage. This either concerns the full MSG Disk for SEVIRI or the whole globe for AVHRR. The albedo product is calculated on a daily basis for SEVIRI (MDAL) and on a quasi -day basis (on the 5 th, 5th and 25th of each month) both for SEVIRI (MTAL, MTAL-R) and AVHRR (ETAL). The LSA SAF MSG/SEVIRI chain processes the full MSG/SEVIRI disk every 5 minutes at the LSA SAF processing centre. The MDAL/MTAL/MTAL-R products are available over the MSG/SEVIRI disk with a spatial resolution of 3 km x 3 km at the sub-satellite point. Due to the polar nature of the orbit, the AVHRR/Metop product follows a different strategy prior to the albedo retrieval step (refer to the ATBD) in comparison with the MSG/SEVIRI derived products. The LSA SAF AVHRR/Metop chain processes all Product Distribution Units (PDUs) at the LSA SAF processing centre. A PDU corresponds to 3 minutes of instrument-specific observation data. The PDUs are aggregated in daily datasets. The ETAL product is available in sinusoidal projection with a spatial resolution of. x.. The characteristics of all four products are summarised in Table 4. Table 4 - Satellite application Facility for Land Surface Analysis (LSA SAF) Meteosat Second Generation (MSG)-based and EPS Meteorological Operation (MetOp)-based surface albedo products characteristics Product Product ID Name collection period Coverage Spatial Resolution Composite Frequency of period Production LSA- MDAL Since January 25 MSG-disk SEVIRI native resolution n.a. Daily LSA-2 MTAL Since February MSG-disk 29 SEVIRI native resolution 3 days days (5th, 5th, 25th of each month) LSA-5 MTAL-R January 25, 24 till December 5, 25 SEVIRI native resolution 3 days days (5th, 5th, 25th of each month) LSA-3 ETAL. x. 2 days days (5th, 5th, 25th of each month) MSG-disk Since January Full Globe 25 (sinusoidal projection) 9

10 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Note that the scientific algorithms are essentially the same for MDAL/MTAL/MTAL-R and ETAL, despite some differences in the input data. More specifically, some details concerning both products, MTAL and MTAL-R: MTAL is the NRT version of the ten-daily albedo product, while MTAL-R is the reprocessed product. Different input data used for the atmospheric correction in the two cases. For the MTAL-R product, atmospheric reanalysis from ECMWF are used instead of the forecast fields that are used for the NRT MTAL product. The main characteristics of the SEVIRI/AVHRR windows are listed in Table 5. Table 5 - Characteristics of the LSA SAF geographical windows. Region Description Maximum ncol Name Maximum nlin COFF LOFF MSGDisk MSG Disk Euro Europe NAfr SAfr SAme GLOB 2.2 Northern Africa Southern Africa Southern America Global AVHRR Product dissemination To have access to the data, one first needs to subscribe to the LSA SAF service and get a user account. For any queries related to the service the following address shall be used: helpdesk.landsaf@ipma.pt. SEVIRI LSA SAF Near Time (NRT) products are disseminated in two fashions: via the project portal (lsa-saf.eumetsat.int ) over the full SEVIRI disk via EUMETCast by splitting the disk into 4 different geographical areas within Meteosat disk (Figure ): Euro Europe, covering all EUMETSAT member states; NAfr Northern Africa encompassing the Sahara and Sahel regions, and part of equatorial Africa. SAfr Southern Africa covering the African continent south of the Equator.

11 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 SAme South American continent within the Meteosat disk. Euro NAfr SAme SAfr Figure : The LSA SAF geographical areas for SEVIRI-based products. The EUMETSAT product navigator can be used to research all available LSA SAF products ( Note that only MDAL and MTAL products are currently accessible via EUMETCAST. MTAL-R data in full SEVIRI disk are not available via this portal but available via the project portal (lsasaf.eumetsat.int ). Metop derived parameters are currently available at Level 3 full globe in sinusoidal projection, centred at ( on, ow), with a resolution of. x. (approx. kmxkm) as one file for daytime and another file for nighttime observations. A global file is disseminated for the time being but distribution per tile may be envisaged. real time examples of the products as well as updated information are also available from the LSA SAF website (lsa-saf.eumetsat.int). 2.3 Geolocation / Rectification Both SEVIRI-based and AVHRR-based albedo fields are generated pixel-bypixel, maintaining the original resolution of SEVIRI level.5 data or AVHRR level b data. ETAL pixel geolocations on the sinusoidal grid result from the sinusoidal projection ( As for SEVIRI the data are kept in the native geostationary projection Files containing the latitude and longitude of the centre of each MSG/SEVIRI pixel may be downloaded from the Land-SAF website (

12 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Longitude: HDF5_LSASAF_MSG_LON_MSG-Disk_2429.bz2 Latitude: HDF5_LSASAF_MSG_LAT_MSG-Disk_248.bz2 More details about the geolocation of SEVIRI pixels (regardingseviri-derived products are concerned) are given as follows. Since the data are in the native geostationary projection, centred at º longitude and with a sampling distance of 3 km at the sub-satellite point, the latitude and longitude of any pixel may be easily estimated. Given the pixel column number, ncol (where ncol= correspond to the westernmost column of the file), and line number, nlin (where nlin= corresponds to the northernmost line), the coordinates of the pixel may be estimated as follows: lon = arctg s2 () ( ) s lat = arctg p2 + sublon s3 s xy longitude (deg) of pixel centre ; latitude (deg) of pixel centre where sub_lon is the sub-satellite point ( sub lon = ) and s = p s n cos x cos y s 2 = sn sin x cos y s 3 = s n sin y s xy = s 2 + s 22 sd = sn = ( p cos x cos y ) ( cos y + p sin y ) p 2 3 p cos x cos y s d cos 2 y + p2 sin2 y where ncol COFF 2 6 CFAC nlin LOFF y = 6 2 LFAC p = 4264 p2 =. 683 p3 = CFAC= LFAC = x= (in Degrees) (in Degrees) The CFAC and LFAC coefficients are column and line scaling factors, which depend on the specific segmentation approach of the input SEVIRI data. Finally, COFF and LOFF are coefficients depending on the location of each Land-SAF geographical area within the Meteosat disk. These are included in the file metadata (HDF5 attributes; Appendix C). For instance, for the full image disk with size 372 x 372 pixels, one would have COFF=857 and LOFF=857. 2

13 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November File Formats 2.4. MDAL At each execution the albedo algorithm generates two types of MDAL output files. Spectral band albedo estimates are included in three different files with the name convention HDF5_LSASAF_MSG_AL_C?_MSG-Disk_YYYYMMDD where?=,2,3 denotes the.6µm,.8µm, and.6µm channels, respectively, where YYYY, MM, and DD, respectively, denote the year, month, and day of data acquisition. Broad-band albedo estimates are included in a single file with the name convention HDF5_LSASAF_MSG_ALBEDO_MSG-Disk_YYYYMMDD MTAL and MTAL-R Similarly HDF5_LSASAF_MSG_AL-C?-D_MSG-Disk_YYYYMMDD and HDF5_LSASAF_MSG_ALBEDO-D_MSG-Disk_YYYYMMDD for both -day products, MTAL and MTAL-R, where YYYYMMDD denotes the year, the month, the decade day (5, 5 or 25) corresponding to the middle of the 3-day composite period (e.g. June 5 MTAL uses daily files from May 2 to June 2). For distribution via EumetCast the prefix S-LSA_- is added. Note that in the distribution via EumetCast, MSG-Disk is replaced by Region, where Region = Euro, NAfr, SAfr or SAme ETAL The -day aggregate AVHRR files are named according to the following convention: HDF5_LSASAF_<Satellite_name>-AVHR_ETAL_GLOBE_YYYYMMDD HDF5_LSASAF_<Satellite_name>-AVHR_ETAL_AL-C?_GLOBE_YYYYMMDD where?=,2,3 denotes the.6µm,.8µm, and.6µm channels, respectively, where <Satellite_name> denotes satellite name (M or M2) where YYYYMMDD denotes the year, the month, the decade day (5, 5 or 25) corresponding to the end of the 2-day composite period (e.g. April 25 ETAL uses daily files from April 6 to April 25). 3

14 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November HDF5 format The LSA SAF products are provided in the HDF5 format developed by the NCSA (National Center for Supercomputing Applications) at the University of Illinois. A comprehensive description as well as libraries for handling HDF5-files in Fortran and C are available at A user friendly graphical interface to open and view HDF5-files can be downloaded from The HDF5-format permits the definition of a set of attributes for providing relevant information. Each LSA SAF product file includes the general attributes listed in Table C for SEVIRI (resp. C3 for AVHRR) of Appendix C. Within the HDF5-files the information is organised in the form of separate datasets. For each dataset a set of additional attributes is available (Table C2 for SEVIRI, resp. C4 for AVHRR of Appendix C.). 2.5 Product Content (MDAL, MTAL, MTAL-R and ETAL) 2.5. Common datasets All LSA SAF surface albedo products share the same dataset structure (Table 6 and 7). Broadband albedo files contain 4 albedo quantities (bi-hemispherical, BH and directional-hemispherical, DH both for broad-band, BB, DH for near infra-red, NI, DH for visible, VI), their respective uncertainty estimates or error (ERR), the quality flag (Q-Flag, see Table 8), and the age of the information (Z_age). Table 6 summarizes these quantities as they are ordered in the HDF5 structure. DH values are calculated for each of the intervals: BB: [.3μm, 4μm], NI: [.7μm, 4μm], and VI: [.4μm,.7μm]. BH estimates are only available for BB. Figure 2 shows an example of the MTAL-R broad-band albedo AL-BB-BH and its error AL-BBBH-ERR, the respective quality flag, and the broad-band albedo AL-NI-DH for January 5, 22. Table 6 - Content of the broadband surface albedo product files, which is common to MDAL, MTAL, MTAL-R and ETAL. Parameter bh a[. 3µm, 4µm ] bh σ [ a[. 3µm, 4µm ] ] dh a[. 3µm, 4µm ] dh σ [ a[. 3µm, 4µm ] ] dh a[. 7µm, 4µm ] dh σ [ a[. 7µm, 4µm ] ] dh a[. 4µm,. 7µm ] dh σ [ a[. 4µm,. 7µm ] ] set Name Unit Range AL-BB-BH [, ] AL-BB-BH-ERR [, ] AL-BB-DH [, ] AL-BB-DH-ERR [, ] AL-NI-DH [, ] AL-NI-DH-ERR [, ] AL-VI-DH [, ] AL-VI-DH-ERR [, ] Variable Type 2-Byte Signed 2-Byte Signed 2-Byte Signed 2-Byte Signed 2-Byte Signed 2-Byte Signed 2-Byte Signed 2-Byte Signed Scale Factor 4

15 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Quality Flag Q-Flag na [, 255] Age of Information() Z_Age days [, 27] a) c) -Byte Unsigned -Byte Signed na b) d) Figure 2: Examples of MTAL-R broadband albedo products for January 5, 22. a) Total broad-band bi-hemispherical (AL-BB-BH); b) total broad-band bi-hemispherical error (AL-BB-BH-ERR); c) quality flag (Q-Flag); and d) near infrared directionalhemispherical (AL-NI-DH). For the quality flag, the decimal number needs to be converted into a binary number and interpreted with the help of Table 8.. Each of the spectral albedo (SP) files corresponding to the nominal SEVIRI bands contains 6 datasets encompassing 2 albedo quantities (BH or DH), their respective uncertainty estimates (ERR), the quality flag (Q-Flag, see Table 8) and the age of the information (Z_age). The technical details are given in Table 8. Note that this attribute is not present both for MTAL and MTAL-R products since it is not relevant to them (refer to ATBD). 5

16 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Table 7 - Content of the spectral surface albedo product files for each channel β. Parameter set Name Unit Range bh AL-SP-BH [, ] AL-SP-BH-ERR [, ] AL-SP-DH [, ] σ [ aβ ] AL-SP-DH-ERR [, ] Quality Flag Q-Flag na [, 255] Age of Information(2) Z_Age days [, 27] aβ bh σ [ aβ ] dh aβ dh Variable Type 2-Byte Signed 2-Byte Signed 2-Byte Signed 2-Byte Signed -Byte Unsigned Int. -Byte Signed Scale Factor na MSG/SEVIRI-derived color composite For illustration purposes, a colour composite image derived by combining the spectral albedo estimates from the 3 spectral output files, is shown in Figure 3. Figure 3: Colour composite image derived from the three spectral directionalhemispherical SEVIRI-based albedo estimates for the st of December Note that this attribute is not present both for MTAL and MTAL-R products. 6

17 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November Metop/AVHRR-derived color composite Similarly, Figure 4 illustrates the colour composite image derived from the three spectral directional-hemispherical AVHRR-based albedo estimates for the 5 th of May 25. Figure 4: Colour composite image derived from the three spectral directionalhemispherical AVHRR-based albedo estimates for the 5 th of May 25 of the ETAL product (R=.6μm, G=.8μm and B=.6μm) Quality flag Finally, Table 8 lists the signification of the numerical values of the (spectral and broadband) albedo quality flag. Bits and propagate the land/sea mask information. Bits 2 to 4 indicate if MSG observations, EPS/Metop information, or additional external information, respectively, were used to produce the result. Bit 5 indicates whether a pixel was flagged as snow covered in the NWC-CMa product for at least one slot of the daily time series. Table 8 - Albedo product quality flag information. Bit Bits - Land Sea Mask Bit 2 MSG Bit 3 EPS/Metop Bit 4 External Information Binary Code Description Ocean Land Space (Outside of MSG disk) Continental water No MSG Observations Including MSG Observations No EPS/Metop Observations Including EPS/Metop Observations No External Information Including External Information 7

18 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Bit 5 Snow Bit 6 Unused Bit 7 Failure 2.6 No Snow Snow Normally Processed Algorithm Failed Summary of Product Characteristics Product Name: Land Surface Albedo Product Code: MDAL or MTAL or MTAL-R or ETAL Product Level: Level 3 Product Parameters: Coverage: MSG full disk (Continental pixels) EPS/Metop global (Continental pixels) Packaging: MSG-Disk, Global Sampling: pixel by pixel basis Spatial Native Resolution: MSG/SEVIRI full resolution (3km 3km at nadir at N / E) EPS/Metop/AVHRR full resolution (kmxkm at nadir) Projection: MSG/SEVIRI Level.5 data projection EPS/Metop/AVHRR sinusoidal Units: dimensionless Range: - Accuracy: objective: %; (refer to the products validations reports for more details) Format: 6 bits signed integer (albedo and uncertainty estimates) 8 bits (quality flag and age of information) Frequency of Generation: daily (MDAL) or ten daily (MTAL, MTAL-R and ETAL) Size of Product Files: MDAL Broad-band Albedo: ~ 38Mb Spectral Albedo: ~ 2Mb for each SEVIRI channel (depending on the window and the compression efficiency) 8

19 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 MTAL/MTAL-R Broadband Albedo: ~.24Gb MTAL/MTAL-R Spectral Albedo: ~.3Gb (per channel) ETAL_Broad-band Albedo GLOBE ~.2Gb ETAL_Spectral Albedo GLOBE ~ 6Mb (per channel) Additional Information: Identification of bands used in algorithm: MSG/SEVIRI VIS.6 MSG/SEVIRI NIR.8 MSG/SEVIRI SWIR.6 EPS/Metop/AVHRR VIS.6 EPS/Metop/AVHRR NIR.8 EPS/Metop/AVHRR SWIR.6 Assumptions on SEVIRI & AVHRR input data: Radiometric and Geometric Calibration Identification of ancillary and auxiliary data: Land/Sea MaskCloud Mask (CMa from NWC SAF software) View Azimuth and Zenith Angles (from LSA SAF System) Solar Azimuth and Zenith Angles (from LSA SAF System) Pixel Latitude (from LSA SAF System) Total Column Water Vapour (from ECMWF model) Ozone Content (from ECMWF model) Atmospheric Pressure (from ECMWF model) Aerosol Optical Thickness at 55 nm (based on a latitude dependent AOT climatology built from input provided by CAMS) Digital Elevation Model (based on USGS GTOPO3) 9

20 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Appendix A. Developers The development and implementation have been carried out under the responsibility of the Centre National de Recherches Météorologiques (CNRM) de Météo-France (MF). Authors: Xavier Ceamanos, Dominique Carrer, Olivier Hautecoeur, Laurent Franchistéguy, Bernhard Geiger, Grégoire Jacob, Nabil Laanaia, Jean-Louis Roujean, and Catherine Meurey Appendix B. Glossary AL: AVHRR: BB: BH: Land Surface Albedo Product Advanced Very High Resolution Radiometer Broad-band Bi-hemispherical BRDF: Bi-directional Reflectance Distribution Function CNRM: Centre National de Recherches Météorologiques CMa: Cloud Mask product developed by the NWC-SAF DH: Directional-hemispherical ECMWF: European Centre for Medium-Range Weather Forecast EPS: EUMETSAT Polar System EUMETSAT: European Meteorological Satellite Organisation HDF: Hierarchical Format IPMA: Instituto Português do Mar e da Atmosfera (Portugal) NIR: Near Infrared Radiation LSA: Land Surface Analysis METEOSAT: Geostationary Meteorological Satellite METOP: Meteorological Operational polar satellites of EUMETSAT MF: Météo-France MSG: Meteosat Second Generation NIR (or NI): Near infrared NOAA: National Oceanic and Atmospheric Administration (USA) NRT: Near Time NWC: NowCasting NWP: Numerical Weather Prediction SAF: Satellite Application Facility SEVIRI: Spinning Enhanced Visible and Infrared Imager SWIR: Shortwave Infrared Radiation VIS (or VI): Visible 2

21 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Appendix C. HDF5-Attributes The set of general attributes common for all LSA SAF files and their possible values are described in the table below. Table C: General HDF5 attributes for AL SEVIRI. Attribute Description Type Allowed Values SAF SAF package LSA CENTRE Institution (generating/disseminating data) IM-PT ARCHIVE_FACILITY Centre where the data is archived IM-PT PRODUCT Defines the name of the product AL-C?, or ALBEDO Array of up to 4 product names, upon which the product is based PARENT_PRODUCT_NAME AL-C?-K2, AL-C?CK, LAT or Array(4) AL-C, AL-C2, AL-C3 4 SPECTRAL_CHANNEL_ID Channel Identification ( bit per channel, where LSB is HRV and MSB is IR3.4; values are if not used, if used.) 5. PRODUCT_ALGORITHM_VERSION Version of the Algorithm that produced the product.2 (MTAL-R) 6.3 (MDAL-R) CLOUD_COVERAGE Indicator of the cloud coverage in the product NWC-CMa OVERALL_QUALITY_FLAG Overall quality flag for the product OK or NOK ASSOCIATED_QUALITY_INFORMATION Several miscellaneous quality indicators for the product - REGION_NAME Processed Region Name MSG-Disk, Euro, NAfr, SAfr, or SAme. COMPRESSION Compression Flag Uncompressed Compressed FIELD_TYPE filed type Product FORECAST_STEP Forecast Step in Hours NC Number of columns Depends on Region NL Number of lines Depends on Region NB_PARAMETERS Number of datasets 5 or 9 NOMINAL_PRODUCT_TIME Production Time YYMMDDhhmmss 2

22 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Attribute Description Type Allowed Values SATELLITE Platform identifier (mission and spacecraft the product originated from) Array() MSG or MSG2 or MSG3 or EPS/Metop INSTRUMENT_ID Instrument which acquired the product or data used by the product Array() SEVI INSTRUMENT_MODE Scanning mode of the instrument at the time of the acquisition.satellite Identification STATIC_VIEW IMAGE_ACQUISITION_TIME Image Acquisition Time (SEVIRI.5 Images) YYMMDD ORBIT_TYPE Coverage of the product (only for EPS/Metop) GEO PROJECTION_NAME Projection name and sub-satellite point GEOS(+.) NOMINAL_LONG Satellite Nominal Longitude as in Level.5 data NOMINAL_LAT Satellite Nominal Latitude as in Level.5 data CFAC Column Scaling Factor (SEVIRI.5 Images) as in Level.5 data LFAC Line Scaling Factor (SEVIRI.5 Images) as in Level.5 data COFF Column Offset (SEVIRI.5 Images) Depends on Region LOFF Line Offset (SEVIRI.5 Images) Depends on Region START_ORBIT_NUMBER First of two orbit numbers in the EPS/Metop product, valid at the starting of the sensing, i.e, at the beginning of a dump END_ORBIT_NUMBER Final of the orbit numbers in the EPS/Metop product, valid at the ascending node crossing, i.e. towards the end of a dump SUB_SATELLITE_POINT_START_LAT Latitude of sub-satellite at start of acquisition. SUB_SATELLITE_POINT_START_LON Longitude of sub-satellite at start of acquisition. SUB_SATELLITE_POINT_END_LAT Latitude of sub-satellite at end of acquisition. SUB_SATELLITE_POINT_END_LON Longitude of sub-satellite at end of acquisition. SENSING_START_TIME UTC date & time at acquisitions start of the product - SENSING_END_TIME UTC date & time at acquisition end of the product - PIXEL_SIZE For image products, size of pixel at nadir. For meteorological products resolution/accuracy 3.km 22

23 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Attribute Type Description Allowed Values GRANULE_TYPE Type description of the item DP PROCESSING_LEVEL Processing Level Applied for generation of the product 3 PRODUCT_TYPE Abbreviation name for the product type rather product category LSA AL-C? or LSA ALBEDO PRODUCT_ACTUAL_SIZE Actual size of the product or PROCESSING_MODE Processing mode for generation of the product N, B, R, or V DISPOSITION_FLAG Disposition status indicator of the product, as set by the UMARF operator O, T, or C TIME_RANGE Temporal Resolution frequency: daily or?days recursive, timescale:? days or STATISTIC_TYPE Statistic Type composition period:? days LSB Lower Significant Bit MSB Most Significant Bit YY - Year; MM-Month; DD Day; hh Hour; mm Minute; ss Second - Character (len=8) - (kind=4) - (kind=8) 23

24 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Table C2: The attributes for each dataset of the HDF5-files for AL SEVIRI are described in the following table. Attribute Descriptio n CLASS set type Value for Albedo sets Type Value for Albedo Error sets Value for Q-Flag sets Value for Age sets PRODUCT Defines the name of the product Name of albedo variant Error of + Name of albedo variant Q-Flag Z_Age PRODUCT_ID Product identification accordingly with WMO tables N_ COLS Number of columns Depends on Region Depends on Region Depends on Region Depends on Region N_ LINES Number of lines Depends on Region Depends on Region Depends on Region Depends on Region NB_BYTES Number of bytes per pixel 2 2 SCALING_FACTOR Scaling factor for the parameter.... OFFSET Offset of the scaling factor.... MISS_VALUE Missing value UNITS Parameter Units dimensionless dimensionles s N/A Days CAL_SLOPE Calibration Constant.... CAL_OFFSET Calibration Constant

25 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Table C3: General HDF5 attributes for AL AVHRR. Attribute Description Type Allowed Values SAF SAF package LSA CENTRE Institution (generating/disseminating data) IM-PT ARCHIVE_FACILITY Centre where the data is archived IM-PT PRODUCT Defines the name of the product AL-C?, or ALBEDO Array of up to 4 product names, upon which the product is based PARENT_PRODUCT_NAME AL-C?-K2, AL-C?CK, LAT or Array(4) AL-C, AL-C2, AL-C3 24 SPECTRAL_CHANNEL_ID Channel Identification ( bit per channel values are if not used, if used.) Version of the Algorithm that produced the product 3 integer values comprised between and 99 X.Y.Z. PRODUCT_ALGORITHM_VERSION Major (X): increase only for a product change..7.minor. Increase only for a new functionality Patch: increase if bug fixed CLOUD_COVERAGE Indicator of the cloud coverage in the product NWC-CMa OVERALL_QUALITY_FLAG Overall quality flag for the product OK or NOK ASSOCIATED_QUALITY_INFORMATION Several miscellaneous quality indicators for the product - GLOBE REGION_NAME Compression Flag COMPRESSION Level of compression between and 9 (9 is the most efficient in terms of data volume 9 FIELD_TYPE filed type Product FORECAST_STEP Forecast Step in Hours NC Number of columns 36 NL Number of lines 8 NB_PARAMETERS Number of datasets 6 or NOMINAL_PRODUCT_TIME Production Time YYMMDDhhmmss Array(4) 25

26 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Attribute Description Type Allowed Values SATELLITE Platform identifier (mission and spacecraft the product originated from) Array() EPS/Metop INSTRUMENT_ID Instrument which acquired the product or data used by the product Array() AVHR INSTRUMENT_MODE Scanning mode of the instrument at the time of the acquisition.satellite Identification NORMAL_VIEW IMAGE_ACQUISITION_TIME Image Acquisition Time (SEVIRI.5 Images) Array(4) YYMMDD ORBIT_TYPE Coverage of the product Array(3) LEO PROJECTION_NAME Projection name Array(5) Sinusoidal NOMINAL_LONG Satellite Nominal Longitude NOMINAL_LAT Satellite Nominal Latitude CFAC LFAC COFF LOFF START_ORBIT_NUMBER Depend on the orbit END_ORBIT_NUMBER Depend on the orbit SENSING_START_TIME UTC date & time at acquisitions start of the product SENSING_END_TIME PIXEL_SIZE UTC date & time at acquisition end of the product For image products, size of pixel at nadir. For meteorological products resolution/accuracy YYMMDDhhmmss Array(4) YYMMDDhhmmss Array(4). Array() GRANULE_TYPE Type description of the item DP Array(2) PROCESSING_LEVEL PRODUCT_TYPE Processing Level Applied for generation of the product Abbreviation name for the product type rather product category 2 Array(2) Array(8) LSA AL-C? or LSA ETAL 26

27 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 Attribute Type Description Allowed Values PRODUCT_ACTUAL_SIZE Actual size of the product TBD Array() PROCESSING_MODE Processing mode for generation of the product N DISPOSITION_FLAG Disposition status indicator of the product, as set by the UMARF operator O TIME_RANGE Temporal Resolution -day recursive, timescale: days or more STATISTIC_TYPE Statistic Type composition period: 3 days SUB_SATELLITE_POINT_START_LAT Latitude of sub-satellite at start of acquisition. SUB_SATELLITE_POINT_START_LON Longitude of sub-satellite at start of acquisition. SUB_SATELLITE_POINT_END_LAT Latitude of sub-satellite at end of acquisition. SUB_SATELLITE_POINT_END_LON Longitude of sub-satellite at end of acquisition. YY - Year; MM-Month; DD Day; hh Hour; mm Minute; ss Second - Character (len=8) - (kind=4) - (kind=8) Table C4: The attributes for each dataset of the HDF5-files for AL AVHRR are described in the following table. Attribute Description Value for Albedo sets Value for Albedo Error sets Value for Q-Flag sets Value for Age sets Error of + Name of albedo variant Q-Flag Z_Age Type CLASS set type PRODUCT Defines the name of the product (ETAL) Name of albedo variant PRODUCT_ID Product identification accordingly with WMO tables N_ COLS Number of columns

28 Doc: SAF/LAND/MF/PUM_AL/. Date: 8 November 28 N_ LINES Number of lines NB_BYTES Number of bytes per pixel 2 2 SCALING_FACTOR Scaling factor for the parameter.... OFFSET Offset of the scaling factor.... MISS_VALUE Missing value UNITS Parameter Units N/A Days CAL_SLOPE Calibration Constant.... CAL_OFFSET Calibration Constant