Shortname: OMSO2G Longname: OMI/Aura Sulfur Dioxide (SO2) Total Column Daily L2 Global 0.25deg Lat/Lon Grid PFS Version: 2.0.3 Date: 2020 June 04 Authors: C. Li, N. Krotkov, P. Leonard, S. Carn, A.J. Krueger PGE Version: 2.0.3 Lead Algorithm Scientists: C. Li, N. Krotkov Lead Algorithm Developer: Peter Leonard Lead PGE Developer: Peter Leonard Other PGE Developer: C. Li Description: > This document specifies the format of the Ozone Monitoring Instrument (OMI) Version 2 OMSO2G product, which is the daily Level 2G (L2G) gridded data product that corresponds to the Version 2 OMSO2 product. The latter is the U.S. OMI Science Team's total column sulphur dioxide orbital Level 2 (L2) swath data product (Reference 1). Each L2G product file (a.k.a. data granule) contains 24 UTC hours of L2 product subsetted onto a longitude-latitude grid. An OMI L2G day is defined to be the 24 hours that lie between UTC times of 0 hours, 0 minutes, 0 seconds and 23 hours, 59 minutes, 59.999999 seconds. Each L2G data granule contains the data for all L2 "scenes" that 1) have observation times that lie within the L2G day in question, 2) have centers that lie within the L2G grid cell in question, and 3) are "good". A "good" OMSO2 L2 scene is defined as one that has i) a solar zenith angle that is less than or equal to 88.0 degrees, and ii) an SO2 column amount that is not equal to the missing value. The adopted L2G grid is a 0.250-degree by 0.250-degree grid in longitude and latitude. The dimensions of this grid are 1440 by 720. The origin of the grid is at lower left. That is, the grid cell at coordinates (1, 1) is centered at (longitude = -179.875 , latitude = -89.875), and the grid cell at coordinates (1440, 720) is centered at (longitude = 179.875 , latitude = 89.875). The adopted L2G grid is consistent with the document entitled "Definition of OMI Grids for Level 3 and Level 4 Data Products" by J.P. Veefkind et al. (Reference 2). The L2G product currently excludes L2 data collected in spatial and spectral zoom modes. Each "good" OMSO2 L2 scene is mapped onto only one L2G grid cell. The number of L2 scenes that are mapped onto a given L2G grid cell can range from 0 to 15. The L2 data are not averaged or weighted in any way in the L2G product. The product is stored as a series of HDF-EOS 5 granules each with sizes of up to 370 MB. The format of each L2G granule is consistent with the Aura File Format Guidelines by C. Craig et al. (Reference 3). Global Metadata: - Metadata Name: AuthorAffiliation Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: PGE Description: Actual is "NASA/GSFC". - Metadata Name: AuthorName Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: PGE Description: > Actual is "C. Li, N. Krotkov, P. Leonard, S. Carn, A.J. Krueger". - Metadata Name: EndUTC Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: PGE Description: > UTC at the end of the L2G granule in "YYYY-MM-DDT23:59:59.999999Z" format. - Metadata Name: FirstLineInOrbit Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1,16 Minimum Value: 1 Maximum Value: 3000 Data Source: PGE Description: > The first line number in each L2 orbit that contributes to the L2G granule. - Metadata Name: GranuleDay Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 1 Maximum Value: 31 Data Source: PGE Description: The day of the month at the start of the L2G granule. - Metadata Name: GranuleDayOfYear Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 1 Maximum Value: 366 Data Source: PGE Description: The day of the year at the start of the L2G granule. - Metadata Name: GranuleMonth Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 1 Maximum Value: 12 Data Source: PGE Description: The month of the year at the start of the L2G granule. - Metadata Name: GranuleYear Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 2000 Maximum Value: 2099 Data Source: PGE Description: The (four-digit) year at the start of the L2G granule. - Metadata Name: HDFEOSVersion Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: HE Description: > The version of HDF-EOS 5 used in production. Example is "HDFEOS_5.1.15". - Metadata Name: InstrumentName Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Valids: OMI Data Source: PGE Description: Actual is "OMI" (see Section 6.1 of Reference 3). - Metadata Name: LastLineInOrbit Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1,16 Minimum Value: 1 Maximum Value: 3000 Data Source: PGE Description: > The last line number in each L2 orbit that contributes to the L2G granule. - Metadata Name: NumberOfLinesMissingGeolocation Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1,16 Minimum Value: 1 Maximum Value: 3000 Data Source: PGE Description: > The number of lines in each L2 orbit that are missing geolocation (a.k.a. number of "bad" lines in each L2 input granule). - Metadata Name: OrbitNumber Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1,16 Minimum Value: 1 Maximum Value: 999999 Data Source: L2 Description: The OMI orbit number for each L2 input granule. - Metadata Name: OrbitPeriod Mandatory: T Data Type: HE5T_NATIVE_DOUBLE Number of Values: 1,16 Minimum Value: 5000.0 Maximum Value: 7000.0 Data Source: PGE Description: The Aura orbital period for each L2 input granule. - Metadata Name: Period Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Valids: Daily,Weekly,Monthly Data Source: PGE Description: The duration of the L2G granule. Actual is "Daily". - Metadata Name: PGEVERSION Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: PCF Description: Example is "2.0.3" (see Appendix K of Reference 4). - Metadata Name: ProcessLevel Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Valids: 2G Data Source: PGE Description: Actual is "2G". - Metadata Name: QAPercentCloudCover Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1,16 Minimum Value: 0 Maximum Value: 100 Data Source: L2 Description: > The percent of data that have cloud cover in each L2 input granule. - Metadata Name: QAPercentMissingData Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1,16 Minimum Value: 0 Maximum Value: 100 Data Source: L2 Description: > The percent of Level 1B calibrated radiance data that is missing from each L2 input granule. - Metadata Name: QAPercentOutOfBoundsData Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1,16 Minimum Value: 0 Maximum Value: 100 Data Source: L2 Description: > The percent of data that are out of bounds in each L2 input granule. - Metadata Name: StartUTC Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: PGE Description: > UTC at the start of the L2G granule in "YYYY-MM-DDT00:00:00.000000Z" format. - Metadata Name: TAI93At0zOfGranule Mandatory: T Data Type: HE5T_NATIVE_DOUBLE Number of Values: 1 Minimum Value: 0.0 Maximum Value: 1.0e+30 Data Source: PGE Description: > The TAI93 time at 0z of the L2G granule (see Section 6.1 of Reference 3). Grid Metadata: - Metadata Name: GCTPProjectionCode Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 99 Data Source: PGE Description: > The GCTP projection code of the L2G grid. Actual is 0, which corresponds to the geographic projection. - Metadata Name: GridName Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Valids: OMI Total Column Amount SO2 Data Source: PGE Description: Actual is "OMI Total Column Amount SO2". - Metadata Name: GridSpacing Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: PGE Description: > Spacing of L2G grid (in degrees). Actual is "(0.25,0.25)". - Metadata Name: GridSpacingUnit Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Valids: deg Data Source: PGE Description: > Unit for GridSpacing. Actual is "deg". - Metadata Name: GridSpan Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Data Source: PGE Description: > Span of L2G grid (in degrees). Actual is "(-180,180,-90,90)". - Metadata Name: GridSpanUnit Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Valids: deg Data Source: PGE Description: > Unit for GridSpan. Actual is "deg". - Metadata Name: MaximumNumberOfCandidatesPerGridCell Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 15 Data Source: PGE Description: > The maximum number of L2 scenes per cell in the L2G grid (this can be as large as 15). - Metadata Name: MinimumNumberOfCandidatesPerGridCell Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 0 Data Source: PGE Description: > The minimum number of L2 scenes per cell in the L2G grid (this is typically 0, because empty L2G grid cells are quite common). - Metadata Name: NumberOfDuplicateScenesAcceptedIntoGrid Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 1500000 Data Source: PGE Description: > The number of L2 scenes accepted into L2G grid cells that already contain one or more L2 scenes. - Metadata Name: NumberOfEmptyGridCells Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 1036800 Data Source: PGE Description: > The number of cells in the L2G grid that do not contain any L2 scenes. - Metadata Name: NumberOfGridCells Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 1 Maximum Value: 1036800 Data Source: PGE Description: The total number of cells in the L2G grid. - Metadata Name: NumberOfLatitudesInGrid Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 1 Maximum Value: 720 Data Source: PGE Description: The number of latitude bins in the L2G grid. - Metadata Name: NumberOfLongitudesInGrid Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 1 Maximum Value: 1440 Data Source: PGE Description: The number of longitude bins in the L2G grid. - Metadata Name: NumberOfMultiplyPopulatedGridCells Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 1036800 Data Source: PGE Description: > The number of cells in the L2G grid that contain two or more L2 scenes. - Metadata Name: NumberOfPopulatedGridCells Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 1036800 Data Source: PGE Description: > The number of cells in the L2G grid that contain one or more L2 scenes. - Metadata Name: NumberOfScenesAcceptedIntoGrid Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 1500000 Data Source: PGE Description: The number of L2 scenes accepted into the L2G grid. - Metadata Name: NumberOfScenesConsideredForGrid Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 1500000 Data Source: PGE Description: The number of L2 scenes considered for the L2G grid. - Metadata Name: NumberOfScenesRejectedFromGrid Mandatory: T Data Type: HE5T_NATIVE_INT Number of Values: 1 Minimum Value: 0 Maximum Value: 1500000 Data Source: PGE Description: The number of L2 scenes rejected from the L2G grid. - Metadata Name: Projection Mandatory: T Data Type: HE5T_NATIVE_CHAR Number of Values: 1 Valids: Geographic Data Source: PGE Description: > The map projection of the L2G grid. Actual is "Geographic" (see Section 6.2 of Reference 3). Grid Dimensions: - Dimension Name: nCandidate Data Type: HE5T_NATIVE_INT Dimension Type: FIXED Data Source: PGE Description: > The L2-candidate-scenes dimension of the L2G grid. The size of this dimension is currently set at 15 (i.e., there can be up to 15 L2 candidate scenes per L2G grid cell). - Dimension Name: nCorners Data Type: HE5T_NATIVE_INT Dimension Type: FIXED Data Source: PGE Description: > The corners dimension of the L2G grid. The size of this dimension is set at 4 (i.e., there are 4 corners per L2 candidate scene). - Dimension Name: nLayers72 Data Type: HE5T_NATIVE_INT Dimension Type: FIXED Data Source: PGE Description: > The GEOS-5 layers dimension of the L2G Grid. The size of this dimension is set at 72 (i.e., there are 72 GEOS-5 layers per L2 candidate scene). - Dimension Name: XDim Data Type: HE5T_NATIVE_INT Dimension Type: FIXED Data Source: PGE Description: > The longitudes dimension of the L2G grid. There are currently 1440 0.250-degree-wide bins between longitudes -180.0 and 180.0 degrees. - Dimension Name: YDim Data Type: HE5T_NATIVE_INT Dimension Type: FIXED Data Source: PGE Description: > The latitudes dimension of the L2G grid. There are currently 720 0.250-degree-wide bins between latitudes -90.0 and 90.0 degrees. Geolocation Fields: - Field Name: GroundPixelArea Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 300.0 Maximum Value: 2200.0 Missing Value: -1.2676506e+30 Units: km2 Data Source: L2 Title: Ground Pixel Area Description: > The area of the tiled ground pixel (in square km) for each L2 candidate scene in each L2G grid cell. - Field Name: GroundPixelQualityFlags Data Type: HE5T_NATIVE_UINT16 Dimensions: nCandidate,YDim,XDim Minimum Value: 0 Maximum Value: 65534 Missing Value: 65535 Units: NoUnits Data Source: L2 Title: Ground Pixel Quality Flags Description: > The ground pixel quality flags for each L2 candidate scene in each L2G grid cell: Bits 0 to 3 together contain the land/water flags: 0 - shallow ocean 1 - land 2 - shallow inland water 3 - ocean coastline/lake shoreline 4 - ephemeral (intermittent) water 5 - deep inland water 6 - continental shelf ocean 7 - deep ocean 8-14 - not used 15 - error flag for land/water Bits 4 to 7 are flags that are set to 0 for FALSE, or 1 for TRUE: Bit 4 - sun glint possibility flag Bit 5 - solar eclipse possibility flag Bit 6 - geolocation error flag Bit 7 - geolocation warning flag Bit 7 is reserved for future use (currently set to 0). 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. (See Section 6.2 of Reference 5 for more details.) - Field Name: Latitude Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -90.0 Maximum Value: 90.0 Missing Value: -1.2676506e+30 Units: degrees_north Data Source: L2 Title: Geodetic Latitude Description: > The geodetic latitude (in degrees) on the ground at the center of each L2 candidate scene in each L2G grid cell. - Field Name: LineNumber Data Type: HE5T_NATIVE_INT Dimensions: nCandidate,YDim,XDim Minimum Value: 1 Maximum Value: 3000 Missing Value: -2147483648 Units: NoUnits Data Source: L2 Title: Line Number of Candidate Scene Description: > The line number for each L2 candidate scene in each L2G grid cell. - Field Name: Longitude Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -180.0 Maximum Value: 180.0 Missing Value: -1.2676506e+30 Units: degrees_east Data Source: L2 Title: Geodetic Longitude Description: > The geodetic longitude (in degrees) on the ground at the center of each L2 candidate scene in each L2G grid cell. - Field Name: NumberOfCandidateScenes Data Type: HE5T_NATIVE_INT Dimensions: YDim,XDim Minimum Value: 0 Maximum Value: 8 Missing Value: 0 Units: NoUnits Data Source: PGE Title: Number of Candidate Scenes Description: > The number of L2 candidate scenes in each L2G grid cell. - Field Name: OrbitNumber Data Type: HE5T_NATIVE_INT Dimensions: nCandidate,YDim,XDim Minimum Value: 1 Maximum Value: 999999 Missing Value: -2147483648 Units: NoUnits Data Source: L2 Title: Orbit Number of Candidate Scene Description: > The orbit number for each L2 candidate scene in each L2G grid cell. - Field Name: PathLength Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 2.0 Maximum Value: 100.0 Missing Value: 1.2676506e+30 Units: NoUnits Data Source: PGE Title: Path Length Description: > The path length [= sec(solar zenith angle) + sec(viewing zenith angle)] for each L2 candidate scene in each L2G grid cell. - Field Name: RelativeAzimuthAngle Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -180.0 Maximum Value: 180.0 Missing Value: -1.2676506e+30 Units: deg(EastofNorth) Data Source: L2 Title: Relative Azimuth Angle (sun + 180 - view) Description: > The relative (sun + 180 - view) azimuth angle (in degrees) on the ground at the center of each L2 candidate scene in each L2G grid cell. - Field Name: SceneNumber Data Type: HE5T_NATIVE_INT Dimensions: nCandidate,YDim,XDim Minimum Value: 1 Maximum Value: 60 Missing Value: -2147483648 Units: NoUnits Data Source: L2 Title: Scene Number of Candidate Scene Description: > The cross-track ground-pixel number for each L2 candidate scene in each L2G grid cell. - Field Name: SecondsInDay Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 0.0 Maximum Value: 86401.0 Missing Value: -1.2676506e+30 Units: s Data Source: L2 Title: Seconds after UTC midnight Description: > The time after UTC midnight (in seconds) for each L2 candidate scene in each L2G grid cell. - Field Name: SolarAzimuthAngle Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -180.0 Maximum Value: 180.0 Missing Value: -1.2676506e+30 Units: deg(EastofNorth) Data Source: L2 Title: Solar Azimuth Angle Description: > The solar azimuth angle (in degrees) defined East-of-North on the ground at the center of each L2 candidate scene in each L2G grid cell. - Field Name: SolarZenithAngle Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 0.0 Maximum Value: 180.0 Missing Value: -1.2676506e+30 Units: deg Data Source: L2 Title: Solar Zenith Angle Description: > The solar zenith angle (in degrees) on the ground at the center of each L2 candidate scene in each L2G grid cell. - Field Name: TerrainHeight Data Type: HE5T_NATIVE_INT16 Dimensions: nCandidate,YDim,XDim Minimum Value: -200 Maximum Value: 10000 Missing Value: -32768 Units: m Data Source: L2 Title: Terrain Height Description: > The terrain height (in meters) at the center of each L2 candidate scene in each L2G grid cell. - Field Name: TiledCornerLatitude Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,nCorners,YDim,XDim Minimum Value: -90.0 Maximum Value: 90.0 Missing Value: -1.2676506e+30 Units: degrees_north Data Source: L2 Title: Tiled Corner Latitude Description: > The corner latitudes for the OMPIXCOR UV-2 tiled ground pixels (CCW relative to flight direction: LL, LR, UR, UL) for each candidate scene in each L2G grid cell. - Field Name: TiledCornerLongitude Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,nCorners,YDim,XDim Minimum Value: -180.0 Maximum Value: 180.0 Missing Value: -1.2676506e+30 Units: degrees_east Data Source: L2 Title: Tiled Corner Longitude Description: > Corner longitudes for the OMPIXCOR UV-2 tiled ground pixels (CCW relative to flight direction: LL, LR, UR, UL) for each candidate scene in each L2G grid cell. - Field Name: Time Data Type: HE5T_NATIVE_DOUBLE Dimensions: nCandidate,YDim,XDim Minimum Value: -5.0d+09 Maximum Value: 1.0d+10 Missing Value: -1.2676506002282294d+30 Units: seconds since 1993-01-01 Data Source: L2 Title: Time at Start of Scan (TAI93) Description: > The TAI93 time (in seconds) for each L2 candidate scene in each L2G grid cell. - Field Name: ViewingAzimuthAngle Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -180.0 Maximum Value: 180.0 Missing Value: -1.2676506e+30 Units: deg(EastofNorth) Data Source: L2 Title: Viewing Azimuth Angle Description: > Viewing azimuth angle (in degrees) defined East-of-North on the ground at the center of each L2 candidate scene in each L2G grid cell. - Field Name: ViewingZenithAngle Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 0.0 Maximum Value: 70.0 Missing Value: -1.2676506e+30 Units: deg Data Source: L2 Title: Viewing Zenith Angle Description: > The viewing zenith angle (in degrees) on the ground at the center of each L2 candidate scene in each L2G grid cell. Data Fields: - Field Name: AlgorithmFlag_SnowIce Data Type: HE5T_NATIVE_UINT8 Dimensions: nCandidate,YDim,XDim Minimum Value: 0 Maximum Value: 3 Missing Value: 255 Units: NoUnits Data Source: L2 Title: Snow-Ice Algorithm Flag Description: > The snow-ice algorithm flag for each L2 candidate scence in each L2G grid cell: 0 - no snow/ice 1 - snow/ice covered and cloud free 2 - possible snow/ice covered and cloud free 3 - snow/ice covered and likely cloud covered - Field Name: CloudPressure Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 0.0 Maximum Value: 1013.25 Missing Value: -1.2676506e+30 Units: hPa Data Source: L2 Title: Effective Cloud Pressure Title: Optical Centroid Pressure (from OMCLDRR) Description: > The optical centroid pressure of the mixed LER model (from OMCLDRR) for each L2 candidate scence in each L2G grid cell. - Field Name: CloudRadianceFraction Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 0.0 Maximum Value: 1.0 Missing Value: -1.2676506e+30 Units: NoUnits Data Source: L2 Title: Cloud Radiance Fraction at 313 nm Description: > The cloud radiance fraction at 313 nm for each L2 candidate scene in each L2G grid cell. - Field Name: ColumnAmountO3 Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 50.0 Maximum Value: 700.0 Missing Value: -1.2676506e+30 Units: DU Data Source: L2 Title: Best Total Ozone Solution (from OMTO3) Description: > The best total ozone solution (in DU) from OMTO3 for each L2 candidate scene in each L2G grid cell. - Field Name: ColumnAmountSO2 Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -10.0 Maximum Value: 2000.0 Missing Value: -1.2676506e+30 Units: DU Data Source: L2 Title: Vertical Column Amount SO2 (GEOS-5 Profile) Description: > The total vertical column amount SO2 (in DU) retrieved using the NASA Principal Component Analysis (PCA) SO2 retrieval algorithm and monthly mean a priori SO2 profile from GEOS-5 model simulations for each L2 candidate scene in each L2G grid cell. - Field Name: ColumnAmountSO2_PBL Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -10.0 Maximum Value: 2000.0 Missing Value: -1.2676506e+30 Units: DU Data Source: L2 Title: Vertical Column Amount SO2 (PBL, Fixed Profile) Description: > The total vertical column amount SO2 (in DU) retrieved using the NASA Principal Component Analysis (PCA) SO2 retrieval algorithm and a prescribed PBL SO2 profile assuming constant mixing ratio within 1 km above the surface and negligible SO2 above 1 km for each L2 candidate scene in each L2G grid cell. - Field Name: ColumnAmountSO2_STL Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -10.0 Maximum Value: 2000.0 Missing Value: -1.2676506e+30 Units: DU Data Source: L2 Title: Vertical Column Amount SO2 (STL, Fixed Profile) Description: > The total vertical column amount SO2 (in DU) retrieved using the NASA Principal Component Analysis (PCA) SO2 retrieval algorithm and a prescribed SO2 profile centered at 18 km for each L2 candidate scene in each L2G grid cell. - Field Name: ColumnAmountSO2_TRL Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -10.0 Maximum Value: 2000.0 Missing Value: -1.2676506e+30 Units: DU Data Source: L2 Title: Vertical Column Amount SO2 (TRL, Fixed Profile) Description: > The total vertical column amount SO2 (in DU) retrieved using the NASA Principal Component Analysis (PCA) SO2 retrieval algorithm and a prescribed SO2 profile centered at 3 km for each L2 candidate scene in each L2G grid cell. - Field Name: ColumnAmountSO2_TRM Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -10.0 Maximum Value: 2000.0 Missing Value: -1.2676506e+30 Units: DU Data Source: L2 Title: Vertical Column Amount SO2 (TRM, Fixed Profile) Description: > The total vertical column amount SO2 (in DU) retrieved using the NASA Principal Component Analysis (PCA) SO2 retrieval algorithm and a prescribed SO2 profile centered at 8 km for each L2 candidate scene in each L2G grid cell. - Field Name: ColumnAmountSO2_TRU Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -10.0 Maximum Value: 2000.0 Missing Value: -1.2676506e+30 Units: DU Data Source: L2 Title: Vertical Column Amount SO2 (TRU, Fixed Profile) Description: > The total vertical column amount SO2 (in DU) retrieved using the NASA Principal Component Analysis (PCA) SO2 retrieval algorithm and a prescribed SO2 profile centered at 13 km for each L2 candidate scene in each L2G grid cell. - Field Name: Flag_RowAnomaly Data Type: HE5T_NATIVE_UINT8 Dimensions: nCandidate,YDim,XDim Minimum Value: 0 Maximum Value: 1 Missing Value: 255 Units: NoUnits Data Source: L2 Title: OMTO3 Row-Anomaly Flag Description: > The OMI row-anomaly flag (from OMTO3) for each L2 candidate scence in each L2G grid cell: 0 - not affected by OMI row anomaly 1 - affected by OMI row anomaly - Field Name: Flag_SAA Data Type: HE5T_NATIVE_UINT8 Dimensions: nCandidate,YDim,XDim Minimum Value: 0 Maximum Value: 1 Missing Value: 255 Units: NoUnits Data Source: L2 Title: South Atlantic Anomaly Flag Description: > The South Atlantic Anomaly (SAA) flag for each L2 candidate scence in each L2G grid cell: 0 - not affected by SAA 1 - affected by SAA - Field Name: GEOS5LayerWeight Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,nLayers72,YDim,XDim Minimum Value: 0.0 Maximum Value: 1.0 Missing Value: -1.2676506e+30 Units: NoUnits Data Source: L2 Title: GEOS-5 Layer Weight Description: > The a priori SO2 profile based on GEOS-5 model simulations, with the layer weight being the fraction of SO2 molecules contributed by each of the 72 vertical layers to the overall SO2 molecules within the entire atmospheric column for each L2 candidate scence in each L2G grid cell. The 72 vertical layers are defined by LayerBottomPressure and a top of the atmosphere pressure of 0.01 hPa. - Field Name: LayerBottomPressure Data Type: HE5T_NATIVE_FLOAT Dimensions: nLayers72 Minimum Value: 0.0 Maximum Value: 1013.25 Missing Value: -1.2676506e+30 Units: hPa Data Source: L2 Title: Layer Bottom Pressure Description: > The pressure at the bottom of each of the 72 vertical layers for which the scattering weight and the a priori SO2 profile are provided. - Field Name: Reflectivity342 Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 0.0 Maximum Value: 1.0 Missing Value: -1.2676506e+30 Units: NoUnits Data Source: L2 Title: Simple Lambertian Equivalent Reflectivity at 342 nm Description: > The Simple Lambertian Equivalent Relfectivity (SLER) at 342 nm for each L2 candidate scene in each L2G grid cell. - Field Name: ScatteringWeight Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,nLayers72,YDim,XDim Minimum Value: 0.0 Maximum Value: 10.0 Missing Value: -1.2676506e+30 Units: NoUnits Data Source: L2 Title: Scattering Weight at 313 nm Description: > The scattering weight at 313 nm for each of the 72 vertical layers as defined by LayerBottomPressure and a top of the atmosphere pressure of 0.01 hPa for each L2 candidate scence in each L2G grid cell. - Field Name: SlantColumnAmountSO2 Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -3.0E17 Maximum Value: 6.0E19 Missing Value: -1.2676506e+30 Units: molec/cm2 Data Source: L2 Title: Slant Column Amount SO2 Description: > The retrieved slant column amount SO2 (in molec/cm2) for each L2 candidate scene in each L2G grid cell. - Field Name: TerrainPressure Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: 0.0 Maximum Value: 1013.25 Missing Value: -1.2676506e+30 Units: hPa Data Source: L2 Title: Terrain Pressure Description: > The terrain pressure (in hPa) at the center of each L2 candidate scene in each L2G grid cell. - Field Name: UVAerosolIndex Data Type: HE5T_NATIVE_FLOAT Dimensions: nCandidate,YDim,XDim Minimum Value: -50.0 Maximum Value: 50.0 Missing Value: -1.2676506e+30 Units: NoUnits Data Source: L2 Title: UV Aerosol Index (342.5-367 nm) Description: > Description: > The UV aerosol index (342.5 and 367 nm) for each L2 candidate scene in each L2G grid cell. Core Metadata: - Metadata Name: AssociatedInstrumentShortName Mandatory: T Data Type: VA20 Number of Values: 1 Valids: OMI Data Source: MCF Description: Actual is "OMI". - Metadata Name: AssociatedPlatformShortName Mandatory: T Data Type: VA20 Number of Values: 1 Valids: Aura Data Source: MCF Description: Actual is "Aura". - Metadata Name: AssociatedSensorShortName Mandatory: T Data Type: VA20 Number of Values: 1 Valids: CCD Ultra Violet,CCD Visible Data Source: MCF Description: Actual is "CCD Ultra Violet". - Metadata Name: AutomaticQualityFlag Mandatory: T Data Type: VA20 Number of Values: 1 Valids: Passed,Suspect,Failed Data Source: PGE Description: Actual is "Failed". - Metadata Name: AutomaticQualityFlagExplanation Mandatory: T Data Type: VA255 Number of Values: 1 Data Source: PGE Description: > Actual is "An automatic quality investigation has not yet been devised." - Metadata Name: DayNightFlag Mandatory: T Data Type: VA5 Number of Values: 1 Valids: Day,Night,Both Data Source: MCF Description: Actual is "Day". - Metadata Name: EastBoundingCoordinate Mandatory: T Data Type: LF Number of Values: 1 Minimum Value: -180.0 Maximum Value: 180.0 Data Source: PGE Description: > The terrestrial longitude (in degrees) of the easternmost data in the L2G granule, which is typically 180.0 degrees. - Metadata Name: EquatorCrossingDate Mandatory: T Data Type: D Number of Values: 1,16 Data Source: L2 Description: > The date of the ascending equator crossing for each L2 input granule. - Metadata Name: EquatorCrossingLongitude Mandatory: T Data Type: LF Number of Values: 1,16 Minimum Value: -180.0 Maximum Value: 180.0 Data Source: L2 Description: > The terrestrial longitude of the ascending equator crossing for each L2 input granule. - Metadata Name: EquatorCrossingTime Mandatory: T Data Type: T Number of Values: 1,16 Data Source: L2 Description: > The time of the ascending equator crossing for each L2 input granule. - Metadata Name: InputPointer Mandatory: T Data Type: VA255 Number of Values: 1,16 Data Source: PCF Description: > A list of the L2 input granules. Example is ("OMI-Aura_L2-OMSO2_2006m1112t2240-o12388_v002-2006m1113t182218.he5", "OMI-Aura_L2-OMSO2_2006m1113t0019-o12389_v002-2006m1113t182705.he5", "OMI-Aura_L2-OMSO2_2006m1113t0157-o12390_v002-2006m1113t182709.he5", "OMI-Aura_L2-OMSO2_2006m1113t0336-o12391_v002-2006m1113t175625.he5", "OMI-Aura_L2-OMSO2_2006m1113t0515-o12392_v002-2006m1113t175625.he5", "OMI-Aura_L2-OMSO2_2006m1113t0654-o12393_v002-2006m1113t202839.he5", "OMI-Aura_L2-OMSO2_2006m1113t0833-o12394_v002-2006m1113t220505.he5", "OMI-Aura_L2-OMSO2_2006m1113t1012-o12395_v002-2006m1113t220052.he5", "OMI-Aura_L2-OMSO2_2006m1113t1151-o12396_v002-2006m1114t172624.he5", "OMI-Aura_L2-OMSO2_2006m1113t1330-o12397_v002-2006m1114t174114.he5", "OMI-Aura_L2-OMSO2_2006m1113t1508-o12398_v002-2006m1114t174530.he5", "OMI-Aura_L2-OMSO2_2006m1113t1647-o12399_v002-2006m1114t172518.he5", "OMI-Aura_L2-OMSO2_2006m1113t1826-o12400_v002-2006m1114t171452.he5", "OMI-Aura_L2-OMSO2_2006m1113t2005-o12401_v002-2006m1114t171451.he5", "OMI-Aura_L2-OMSO2_2006m1113t2144-o12402_v002-2006m1114t171454.he5", "OMI-Aura_L2-OMSO2_2006m1113t2323-o12403_v002-2006m1114t171603.he5"). - Metadata Name: LocalGranuleID Mandatory: T Data Type: VA80 Number of Values: 1 Data Source: PGE Description: > The name of the L2G granule. An example is "OMI-Aura_L2G-OMSO2G_2006m1113_v002-2007m0706t212329.he5" (see Appendix E of Reference 4). - Metadata Name: LocalityValue Mandatory: T Data Type: VA20 Number of Values: 1 Data Source: MCF Description: Actual is "Global". - Metadata Name: LOCALVERSIONID Mandatory: T Data Type: VA60 Number of Values: 1 Data Source: PCF Description: > MD5 fingerprint of the L2G granule. Example valids are "RFC1321 MD5 = not yet calculated" and "RFC1321 MD5 = [0-9,a-f]{32}". - Metadata Name: NorthBoundingCoordinate Mandatory: T Data Type: LF Number of Values: 1 Minimum Value: -90.0 Maximum Value: 90.0 Data Source: PGE Description: > The terrestrial latitude (in degrees) of the northernmost data in the L2G granule, which typically lies in the range from 65.0 to 90.0 degrees. - Metadata Name: OperationalQualityFlag Mandatory: T Data Type: VA20 Number of Values: 1 Valids: > Passed,Failed,Being Investigated,Not Investigated,Inferred Passed, Inferred Failed,Suspect Data Source: PGE Description: > Actual is "Passed". - Metadata Name: OperationalQualityFlagExplanation Mandatory: T Data Type: VA255 Number of Values: 1 Data Source: PGE Description: > Actual is "This granule passed operational tests that were administered by the OMI SIPS. QA metadata was extracted and the file was successfully read using standard HDF-EOS utilities.". - Metadata Name: OrbitNumber Mandatory: T Data Type: I Number of Values: 1,16 Minimum Value: 1 Maximum Value: 999999 Data Source: L2 Description: The OMI orbit number for each L2 input granule. - Metadata Name: ParameterName Mandatory: T Data Type: VA40 Number of Values: 1 Valids: Total Column Sulphur Dioxide Data Source: PGE Description: > The measured science parameter expressed in the L2G granule. Actual is "Total Column Sulphur Dioxide". - Metadata Name: PGEVERSION Mandatory: T Data Type: VA10 Number of Values: 1 Data Source: PCF Description: Example is "2.0.3" (see Appendix K of Reference 4). - Metadata Name: ProductionDateTime Mandatory: T Data Type: DT Number of Values: 1 Data Source: TK Description: The date and time of the Level 2G processing. - Metadata Name: QAPercentCloudCover Mandatory: T Data Type: I Number of Values: 1 Minimum Value: 0 Maximum Value: 100 Data Source: PGE Description: > An average for the entire L2G granule of the percent of data that have cloud cover. - Metadata Name: QAPercentMissingData Mandatory: T Data Type: I Number of Values: 1 Minimum Value: 0 Maximum Value: 100 Data Source: PGE Description: > An average for the entire L2G granule of the percent of missing Level 1B calibrated radiance data. - Metadata Name: QAPercentOutOfBoundsData Mandatory: T Data Type: I Number of Values: 1 Minimum Value: 0 Maximum Value: 100 Data Source: PGE Description: > An average for the entire L2G granule of the percent of data that are out of bounds. - Metadata Name: RangeBeginningDate Mandatory: T Data Type: D Number of Values: 1 Data Source: PGE Description: The year, month and day when the L2G granule begins. - Metadata Name: RangeBeginningTime Mandatory: T Data Type: T Number of Values: 1 Data Source: PGE Description: > The hour, minute, second and fraction of a second when the L2G granule begins. - Metadata Name: RangeEndingDate Mandatory: T Data Type: D Number of Values: 1 Data Source: PGE Description: The year, month and day when the L2G granule ends. - Metadata Name: RangeEndingTime Mandatory: T Data Type: T Number of Values: 1 Data Source: PGE Description: > The hour, minute, second and fraction of a second when the L2G granule ends. - Metadata Name: REPROCESSINGACTUAL Mandatory: T Data Type: VA20 Number of Values: 1 Valids: > processed 1 time,processed 2 times,processed 3 times,processed 4 times Data Source: PCF Description: > An indication of what reprocessing has been performed on the L2G granule. - Metadata Name: ReprocessingPlanned Mandatory: T Data Type: VA40 Number of Values: 1 Valids: > no further update anticipated,further update is anticipated, further update anticipated using enhanced PGE Data Source: DP Description: Actual is "further update is anticipated". - Metadata Name: ScienceQualityFlag Mandatory: T Data Type: VA20 Number of Values: 1 Valids: > Passed,Failed,Being Investigated,Not Investigated,Inferred Passed, Inferred Failed,Suspect Data Source: DP Description: Actual is "Not Investigated". - Metadata Name: ScienceQualityFlagExplanation Mandatory: T Data Type: VA255 Number of Values: 1 Data Source: DP Description: > Actual is "An updated science quality flag and explanation is put in the product .met file when a granule has been evaluated. The flag value in this file, Not Investigated, is an automatic default that is put into every granule during production.". - Metadata Name: ShortName Mandatory: T Data Type: VA8 Number of Values: 1 Valids: OMSO2G Data Source: MCF Description: Actual is "OMSO2G". - Metadata Name: SouthBoundingCoordinate Mandatory: T Data Type: LF Number of Values: 1 Minimum Value: -90.0 Maximum Value: 90.0 Data Source: PGE Description: > The terrestrial latitude (in degrees) of the southernmost data in the L2G granule, which typically lies in the range from -90.0 to -65.0 degrees. - Metadata Name: VERSIONID Mandatory: T Data Type: SI Number of Values: 1 Minimum Value: 0 Maximum Value: 999 Data Source: PCF Description: Example is 3. - Metadata Name: WestBoundingCoordinate Mandatory: T Data Type: LF Number of Values: 1 Minimum Value: -180.0 Maximum Value: 180.0 Data Source: PGE Description: > The terrestrial longitude (in degrees) of the westernmost data in the L2G granule, which is typically -180.0 degrees. Product Specific Attributes: - Metadata Name: NrMeasurements Mandatory: T Data Type: I Number of Values: 1 Minimum Value: 0 Maximum Value: 30000 Data Source: PGE Description: > The number of measurements used to create the L2G granule. - Metadata Name: NrSpatialZoom Mandatory: T Data Type: I Number of Values: 1 Minimum Value: 0 Maximum Value: 0 Data Source: PGE Description: > The number of measurements in spatial zoom mode. Actual is 0, because zoom measurements are excluded from the L2G granule. - Metadata Name: NrSpectralZoom Mandatory: T Data Type: I Number of Values: 1 Minimum Value: 0 Maximum Value: 0 Data Source: PGE Description: > The number of measurements in spectral zoom mode. Actual is 0, because zoom measurements are excluded from the L2G granule. - Metadata Name: NrZoom Mandatory: T Data Type: I Number of Values: 1 Minimum Value: 0 Maximum Value: 0 Data Source: PGE Description: > The number of measurements in zoom modes. Actual is 0, because zoom measurements are excluded from the L2G granule. - Metadata Name: SolarEclipse Mandatory: T Data Type: VA10 Number of Values: 1 Valids: TRUE,FALSE Data Source: PGE Description: > The indicator that during part of the measurements a solar eclipse occurred. - Metadata Name: SouthAtlanticAnomalyCrossing Mandatory: T Data Type: VA10 Number of Values: 1 Valids: TRUE,FALSE Data Source: PGE Description: > The indicator that during part of the measurements the spacecraft was in the South Atlantic Anomaly. Archived Metadata: - Metadata Name: ESDTDescriptorRevision Mandatory: T Data Type: VA10 Number of Values: 1 Data Source: MCF Description: > The version of the ESDT descriptor file as determined by ECS. - Metadata Name: LongName Mandatory: T Data Type: VA80 Number of Values: 1 Valids: > OMI/Aura Sulfur Dioxide (SO2) Total Column Daily L2 Global 0.25deg Lat/Lon Grid Data Source: MCF Description: > Actual is "OMI/Aura Sulfur Dioxide (SO2) Total Column Daily L2 Global 0.25deg Lat/Lon Grid". References: > 1. "Version 2 OMSO2 README File" (29 February 20201) (https://aura.gesdisc.eosdis.nasa.gov/data/Aura_OMI_Level2/OMSO2.003/doc/OMSO2Readme_V2.pdf) 2. "Definition of OMI Grids for Level 3 and Level 4 Data Products" (OMI-Grids_L3L4, SD-OMIE-KNMI-443, 25 January 2005) 3. "A File Format for Satellite Atmospheric Chemistry Data Based On Aura File Format Guidelines" (OMI-AURA-DATA-GUIDE, ESDS-RFC-009, May 2008) 4. "OMI Science Software Delivery Guide for Version 0.9" (OMI-SSDG-0.9.10, Version 0.9.10, 22 June 2005) 5. "OMI GDPS Input/Output Data Specification (IODS) Volume 2" (OMI-GDPS-IODS-2, SD-OMIE-7200-DS-467, Issue 8, 3 November 2009)