Shortname: OMGLER Longname: OMI land and water merged GLER product 1-Orbit L2 Swath 13x24 km PFS Version: 0.0.1 Date: 25 July 2019 Author(s): Wenhan Qin (SSAI) PGE Version: 1.0.0 Lead Algorithm Scientist: Jonna.Joiner@nasa.gov (NASA/GSFC) Lead Software Developer: Wenhan Qin (SSAI) Other Software Developers: Zachary Fasnacht (SSAI), Brad Fisher (SSAI) Description: > This document specifies the data and metadata fields for the OMI GLER (geometry-dependent surface Lambertian-equivalent reflectivity) product. This product provides LER at OMI viewing geometry over the OMI field of view. GLER is derived from from simulations of Rayleigh-only top-of-atmosphere (TOA) radiances assuming MODIS average surface BRDF over land and Cox-Munk slope distribution function for water surface reflection plus water-leaving radiance contribution backscattered by water column into the atmosphere. File-Level Attributes: - Attribute: AppVersion Mandatory: T DataType: H5T_NATIVE_CHAR Number of Values: 1 Data Source: N/A Description: Version number for App (e.g., .0.0.1) - Attribute: AuthorAffiliation Mandatory: T Data Type: H5T_NATIVE_CHAR Number of Values: 1 Range or Valids: Not applicable (free format). Data Source: ControlFile Description: Actual is "NASA/GSFC". - Metadata Name: AuthorName Mandatory: T Data Type: H5T_NATIVE_CHAR Number of Values: 1 Range or Valids: Not applicable (free format). Data Source: ControlFile Description: Actual is "U.S. OMI Science Team". - Attribute: GranuleDay Mandatory: T Data Type: H5T_NATIVE_INT16 Number of Values: 1 Range or Valids: 1 to 31 Data Source: PGE Description: The day of the month at the start of the granule. - Attribute: GranuleMonth Mandatory: T Data Type: H5T_NATIVE_INT16 Number of Values: 1 Range or Valids: 1 to 12 Data Source: PGE Description: The month at the start of the granule. - Attribute: GranuleYear Mandatory: T Data Type: H5T_NATIVE_INT16 Number of Values: 1 Range or Valids: 2003 to 2099 Data Source: PGE Description: The (four-digit) year at the start of the granule. - Attribute: InstrumentName Mandatory: T Data Type: H5T_NATIVE_CHAR Number of Values: 1 Range or Valids: Valids are "HIRDLS", "MLS", "OMI", "MODIS" and "TES". Data Source: ControlFile Description: Actual is "OMI". - Attribute: LongName Mandatory: T Data Type: H5T_NATIVE_CHAR number_of_values: 1 Description: > The ESDT Long Name of the product. Actual is "OMI/Aura Global Geometry-Dependent Surface LER 1-Orbit L2 Swath 13x24km". - Attribute: OrbitNumber Mandatory: T Data Type: H5T_NATIVE_CHAR Number of Values: 1 Description: Orbit Number for Aura/OMI provided as a character string. - Attribute: ShortName Mandatory: T Data_type: H5T_NATIVE_CHAR Number_of_values: 1 Description: > The ESDT Short Name of the product. Actual is "OMGLER". Swath Dimensions: - Dimension Name: nTimes Data Type: H5T_NATIVE_INT16 Dimension Type: FIXED Number of Values: 1 Range or Valids: 0 to 9999 Data Source: OML1BRVG Description: The number of "scan" lines in the swath. - Dimension Name: nXtrack Data Type: H5T_NATIVE_INT16 Dimension Type: FIXED Number of Values: 1 Range or Valids: 1 to 60 Data Source: OML1BRVG Description: The number of ground pixels per "scan" line. - Dimension Name: nWavelength Data Type: H5T_NATIVE_INT16 Dimension Type: FIXED Number of Values: 1 Range or Valids: 1 to 6 Data Source: control file parameter Description: The number of wavelength in GLER data set. GEOLOCATION FIELDS Group: - Dataset: Fov75Area Data Type: H5T_NATIVE_FLOAT Dimensions: nXtrack _FillValue: -1.0E30 Units: km^2 Data Source: OMPIXCOR LongName: Mean Area for 75% Field of View Pixels on the WGS-85 Ellipsoid Description: Estimated area for OMI each row along the cross track at 75% power. - Dataset: Fov75CornerLatitude Data Type: H5T_NATIVE_FLOAT Dimensions: nTime x nXtrack x 4 _FillValue: -1.0E30 Units: degrees_north Data Source: OMPIXCOR LongName: Corner Latitudes for 75% Field of View Pixels on the WGS-85 Ellipsoid (CCW relative to flight direction: LL,LR,UR,UL) Description: Corner Latitudes for 75% Field of View Pixels on the WGS-85 Ellipsoid (CCW relative to flight direction: LL,LR,UR,UL) - Dataset: Fov75CornerLongitude Data Type: H5T_NATIVE_FLOAT Dimensions: nTime x nXtrack x 4 _FillValue: -1.0E30 Units: degrees_east Data Source: OMPIXCOR LongName: Corner Longitudes for 75% Field of View Pixels on the WGS-85 Ellipsoid (CCW relative to flight direction: LL,LR,UR,UL) Description: Corner Longitudes for 75% Field of View Pixels on the WGS-85 Ellipsoid (CCW relative to flight direction: LL,LR,UR,UL) - Dataset: GroundPixelQualityFlags Data Type: H5T_NATIVE_INT16 Dimensions: nTime x nXtrack MissingValue: -1 Data Source: OML1BRVG LongName: OMI Ground Pixel Quality Flags Description: > Bits 0 to 5, 7 - not used Bit 6 - geolocation error flag Bits 8 to 14 together contain the snow/ice flags (based on NISE): 0 - snow-free land 1-100 - sea ice concentration (percent) 101 - permanent ice (Greenland, Antarctica) 102 - not used 103 - dry snow 104 - ocean (NISE-255) 105-123 - reserved for future use 124 - mixed pixels at coastline (NISE-252) 125 - suspect ice value (NISE-253) 126 - corners undefined (NISE-254) 127 - error Bit 15 - NISE nearest neighbor filling flag. - Dataset: Latitude Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack Valid_min: -90.0 Valid_max: 90.0 _FillValue: -999.0 Units: degrees_north Data Source: OML1BRVG LongName: Latitude for OMI Pixel Description: The terrestrial latitude (in degrees) at the center of the ground pixel for the OMI pixel. - Dataset: Longitude Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack Valid_min: -180.0 Valid_max: 180.0 _FillValue: -999.0 Units: degrees_east Data Source: OML1BRVG LongName: Longitude for OMI Pixel Description: The terrestrial Longitude (in degrees) at the center of the ground pixel for the OMI pixel. - Dataset: RelativeAzimuthAngle Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: degrees Data Source: OML1BRVG LongName: Relative Azimuthal Angle Description: The relative azimuthal angle (in degrees) for Aura/OMI. - Dataset: SolarAzimuthAngle Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: degrees Data Source: OML1BRVG LongName: Solar azimuth angle Description: The solar azimuth angle (in degrees) at the center of the OMI ground pixel. - Dataset: SolarZenithAngle Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: degrees Data Source: OML1BRVG LongName: Solar zenith angle Description: The solar zenith angle (in degrees) at the center of the OMI ground pixel. - Dataset: ViewingAzimuthAngle Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: degrees Data Source: OML1BRVG LongName: Viewing azimuth angle Description: The viewing azimuth angle (in degrees) relative to Aura/OMI. - Dataset: ViewingZenithAngle Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: degrees Data Source: OML1BRVG LongName: Viewing zenith angle Description: The viewing zenith angle (in degrees) relative to Aura/OMI. - Dataset: Time Data Type: H5T_NATIVE_DOUBLE Dimensions: nTimes _FillValue: -999.0 Units: seconds since 1993-01-01 00:00:00Z Data_source: OML1BRVG LongName: Time at start of scan (s, TAI93) Description: The OMI along track time at start of scan relative to January 1, 1993 (i.e., TAI93). Data Fields Group: - Dataset: Wavelength Data Type: H5T_NATIVE_FLOAT Dimensions: nWavelength _FillValue: -999.0 Units: nm Data Source: ControlFile LongName: Wavelength Description: The wavelengths in GLER data set. - Dataset: LandAreaFraction Data Type: H5T_NATIVE_INT16 Dimensions: nTimes x nXtrack _FillValue: -999 ScaleFactor: 0.001 units: NoUnits Data Source: MODIS land-water mask flags with MCD43GF, 30 arc-second resolution long_name: Land area fraction Description: Mean pixel land area fraction from all good MODIS pixels co-located on OMI. - Dataset: LERRatio Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: NoUnits LongName: 440/466 OMI-derived LER ratio Description: 440/466 LER ratio derived from clear-sky monthly OMI measured radiances. - Dataset: TerrainHeight Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: km Data Source: ETOPO2v2 - NOAA NCEI surface topographic data at 2 arc minute resolution LongName: Pixel average ETOPO-based elevation Description: Mean pixel elevation from ETOPO2v2 collocated on OMI. - Dataset: TerrainHeightStdDev Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: km Data Source: ETOPO2v2 - NOAA NCEI surface topographic data at 2 arc minute resolution LongName: Standard deviation of ETOPO-based pixel elevation Description: Standard deviation of pixel elevation from ETOPO2v2 collocated on OMI. - Dataset: TerrainPressure Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: hPa Data Source: GMI - Global Modeling Initiative model driven by NASA GMAO GEOS-5 global data assimilation system, 1 x 1.25 deg resolution LongName: GMI-based terrain pressure from terrain height Description: Terrain pressure interpolated from GMI-gridded terrain height and OMI pixel elevation - Dataset: TerrainPressureStdDev Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: hPa Data Source: GMI - Global Modeling Initiative model driven by NASA GMAO GEOS-5 global data assimilation system, 1 x 1.25 deg resolution LongName: Standard deviation of GMI-based terrain pressure Description: Standard deviation of pixel terrain pressure interpolated from GMI-gridded terrain height and OMI pixel elevation - Dataset: GLER Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack x nWavelength _FillValue: -999.0 Units: NoUnits LongName: Geometry-dependent surface LER Description: OMI L2 pixel-based Geometry-dependent surface LER - Dataset: ComputedTOARadiance Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack x nWavelength _FillValue: -999.0 Units: 1/sr LongName: Computed area-weighting land and water combined TOA radiance Description: Area-weighting land and water combined TOA radiance calculated from VLIDORT-generated LUTs interpolation - Dataset: I0 Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack x nWavelength _FillValue: -999.0 Units: 1/sr LongName: Atmospheric path scattering radiance Description: Atmospheric path scattering radiance calculated from VLIDORT-generated LUTs interpolation - Dataset: T Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack x nWavelength _FillValue: -999.0 Units: 1/sr LongName: Atmospheric transmitted radiance Description: Atmospheric transmitted radiance calculated from VLIDORT-generated LUTs interpolation - Dataset: Sb Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack x nWavelength _FillValue: -999.0 Units: NoUnits LongName: Atmospheric spherical reflectivity Description: Atmospheric spherical reflectivity calculated from VLIDORT-generated LUTs interpolation - Dataset: FIso Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: NoUnits Data Source: MCD43GF (V005 gap-filled MODIS surface BRDF/Albedo product at 30 arc-second resolution and Band 3) LongName: Ross-Thick Li-Sparse isotropic kernel coefficient for land Description: OMI pixel averaged Ross-Thick Li-Sparse isotropic kernel coefficient for land - Dataset: FVol Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: NoUnits Data Source: MCD43GF (V005 gap-filled MODIS surface BRDF/Albedo product at 30 arc-second resolution and Band 3) LongName: Ross-Thick Li-Sparse volumetric kernel coefficient for land Description: OMI pixel averaged Ross-Thick Li-Sparse volumetric kernel coefficient for land - Dataset: FGeo Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: NoUnits Data Source: MCD43GF (V005 gap-filled MODIS surface BRDF/Albedo product at 30 arc-second resolution and Band 3) LongName: Ross-Thick Li-Sparse geometric kernel coefficient for land Description: OMI pixel averaged Ross-Thick Li-Sparse geometric kernel coefficient for land - Dataset: LandBRF Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: NoUnits LongName: Land surface Bidirectional Reflectance Factor at Band 3 (470 nm) Description: OMI pixel BRF using OMI pixel geometry and pixel averaged BRDF parameters (FIso, FVol and FGeo) - Dataset: LandBRFStdDev Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: NoUnits LongName: Land BRF standard deviation at Band 3 (470 nm) Description: Land OMI pixel BRF standard deviation calculated from standard deviations of FIso, FVol and FGeo - Dataset: LandLER Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: NoUnits LongName: Land surface GLER at 466 nm Description: Land OMI pixel LER calculated using land components of computedTOARadiance, I0, T and Sb - Dataset: ChlorophyllConcentration Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: mg/m^3 Data Source: MODIS Aqua LongName: Chlorophyll concentration in water Description: Monthly chlorophyll concentration in water at 4 km spatial resolution - Dataset: WindSpeed Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: m/s Data Source: AMSR-E (Advanced Microwave Scanning Radiometer for EOS onboard NASA Aqua) before Oct 2011; SSMIS (Special Sensor Microwave Imager/Sounder onboard the US Air Force Defense Meteorological Satellite F16) after Oct 2011 LongName: Wind Speed at 10 m over water surface Description: Wind Speed at 10 m over water surface at 0.25 deg spatial resolution - Dataset: WindDirection Data Type: H5T_NATIVE_FLOAT Dimensions: nTimes x nXtrack _FillValue: -999.0 Units: degrees Data Source: GEOS-5 FP-IT (NASA’s Goddard Earth Observing System Model Forward Processing for Instrument Teams) LongName: FP-IT Wind direction over water Description: hourly FP-IT Wind direction over water at 0.625 deg x 0.5 deg spatial resolution - Dataset: GLERQualityFlags Data Type: H5T_NATIVE_INT16 Dimensions: nTime x nXtrack _FillValue: -999.0 Units: NoUnits LongName: GLER Quality Flags Description: > Bit 0 - invalid land fraction Bit 1 - invalid SAA Bit 2 - high SZA (> 86 deg) Bit 3 - warning flag for SZA > 70 deg in MCD43GF Bit 4 - missing land radiance component for mixed pixel Bit 5 - missing water radiance component for mixed pixel Bits 6-15 - not used - Dataset: ProcessingFlags Data Type: H5T_NATIVE_INT16 Dimensions: nTime x nXtrack _FillValue: -999.0 Units: NoUnits LongName: Processing Flags Description: > Bit 0 - Kleipool LER climatology Bit 1 - OMI-derived LER for snow land Bit 2 - OMI-derived LER for sea ice portion Bit 3 - FP-IT windspeed Bit 4 - AMSR-E windspeed Bit 5 - F16 SSMIS windspeed Bit 6 - Wind speed <0.4 m/s Bit 7 - Chlorophyll monthly climatology Bit 8 - Chlorophyll yearly mean Bit 9 - Chlorophyll default for open ocean (0.1) Bit 10 - Chlorophyll default for inland water (1.0) Bit 11 - Chlorophyll fillvalue Bit 12 - Chlorophyll concentration >10.0 mg/m^3 Bit 13 - default value (0.95) of 440/466 LER ratio climatology Bits 14-15 - not used