Product General Information:
ESDT ShortName: OMIAuraSO2G
ESDT LongName: OMI/Aura TOMS SO2 Vertical Column Daily L2 0.25deg Lat/Lon Grid
PFS Version: 0.0.3
PFS Date: 2014-08-23
PFS Author: P. Leonard (ADNET)
App Version: 0.0.1
App Developers: P. Leonard (ADNET)
App Scientists: Nick Krotkov (NASA), P.K. Bhartia (NASA), Brad Fisher (SSAI), Can Li (ESSIC)
Product Overview: >
This document specifies the format for the OMIAuraSO2G product, which
is the daily Level 2G (L2G) gridded product that corresponds to the
OMIAuraSO2 Level 2 (L2) swath product. The latter contains SO2 column
amount estimates based on OMI (Ozone Monitoring Instrument) observations,
and is tied to the OMSO2 (Reference 1) and OMTO3 (Reference 2) products.
The L2G product contains 24 UTC hours of L2 product subsetted onto a
longitude-latitude grid.
The adopted L3G grid is a 0.25-degree by 0.25-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 with (1-based)
indices (1, 1) is centered at (longitude = -179.875, latitude = -89.875).
The grid cell with indices (1440, 720) is centered at (longitude =
179.875, latitude = 89.875). The center of the grid, (longitude = 0.000,
latitude = 0.000), corresponds to the corners of four grid cells.
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 3).
An 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.
The L2G product contains the data for all observations that are "good".
A "good" observation is defined as one that has
1) an observation time that lies within the specified L2G day,
2) a solar zenith angle that is less than or equal to 88.0 degrees, and
3) an SO2 column amount 15-km (STL) that is not equal to the missing value.
Each "good" observation is mapped onto only one L2G grid cell.
The number of observations that are mapped onto a given L2G grid cell can
range from 0 to 15, and the corresponding data are stored in an additional
dimension of the grid.
The L2 data are not averaged or weighted in any way in the L2G product.
The L2G product currently excludes L2 data collected in OMI spatial and
spectral zoom modes.
The OMIAuraSO2G product is stored as one HDF5 grid file for each L2G
day of OMIAuraSO2 L2 data, and has a size of up to 150 Mb. The Metadata
in the product file are consistent with the MEaSUREs Metadata requirements
(References 4 and 5). The field names and dimension order are inspired
by the Aura File Format Guidelines document (Reference 6).
File-Level Attributes:
- attribute: AuthorAffiliation
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The affiliation of the author of the product. Actual is "NASA/GSFC".
- attribute: AuthorName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The name of the author of the product. Actual is "N. Krotkov, et al.".
- attribute: Conventions
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The Metadata Conventions used. Actual is "CF-1.0".
- attribute: DayNightFlag
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The flag that indicates whether the product includes day-side observations, night-side observations, or both. Actual is "Day".
- attribute: EastBoundingCoordinate
mandatory: T
data_type: H5T_NATIVE_REAL
number_of_values: 1
valid_min: -180.0
valid_max: 180.0
description: >
The terrestrial longitude (in degrees) of the easternmost data in the L2G granule.
- attribute: EndUTC
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
UTC at the end of the L2G granule in "YYYY-MM-DDT23:59:59.999999Z" format.
- attribute: EquatorCrossingDate
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1,16
description: >
The UTC year, month and day of the ascending equator crossing for each L2 input granule. Example is "2010-12-25".
- attribute: EquatorCrossingLongitude
mandatory: T
data_type: H5T_NATIVE_REAL
number_of_values: 1,16
valid_min: -180.0
valid_max: 180.0
description: >
The longitude of the ascending equator crossing for each L2 input granule.
- attribute: EquatorCrossingTime
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1,16
description: >
The UTC hour, minute and second of the ascending equator crossing in each L2 input granule. Example is "12:00:00".
- attribute: FirstLineInOrbit
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1,16
valid_min: 1
valid_max: 1700
description: >
The first line number in each L2 orbit that contributes to the L2G granule.
- attribute: GranuleDay
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 1
valid_max: 31
description: >
The UTC day of the month at the start of the L2G granule.
- attribute: GranuleDayOfYear
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 1
valid_max: 366
description: >
The UTC day of the year at the start of the L2G granule.
- attribute: GranuleMonth
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 1
valid_max: 12
description: >
The UTC month at the start of the L2G granule.
- attribute: GranuleYear
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 2004
valid_max: 2020
description: >
The (four-digit) UTC year at the start of the L2G granule.
- attribute: GridName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
valids: OMI Total Column Amount SO2
description: >
Actual is "OMI Total Column Amount SO2".
- attribute: GridProjection
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
valids: Geographic
description: >
The map projection of the L2G grid. Actual is "Geographic" (see Section 6.2 of Reference 6).
- attribute: GridSpacing
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
Spacing of L2G grid (in degrees). Actual is "(0.25,0.25)".
- attribute: GridSpacingUnit
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
valids: deg
description: >
Unit for GridSpacing. Actual is "deg".
- attribute: GridSpan
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
Span of L2G grid (in degrees). Actual is "(-180,180,-90,90)"
- attribute: GridSpanUnit
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
valids: deg
description: >
Unit for GridSpan. Actual is "deg".
- attribute: HDFVersion
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The version of HDF used to create the L2G product file. Example is "5-1.8.8".
- attribute: identifier_product_doi
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The Digital Object Identifier. Actual is "10.5067/MEASURES/SO2/DATA211".
- attribute: identifier_product_doi_authority
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The Digital Object Identifier. Actual is "http://dx.doi.org/".
- attribute: InputFiles
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The names of each L2 input file used to produce the L2G product file.
- attribute: InstrumentShortName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The Short Name of the instrument. Actual is "OMI".
- attribute: LastLineInOrbit
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1,16
valid_min: 1
valid_max: 1700
description: >
The last line number in each L2 orbit that contributes to the L2G granule.
- attribute: LocalGranuleID
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The actual name of the L2G product file. Example is "OMI-Aura_L2G-OMIAuraSO2G_2002m0630t2354-o21434_v03-00-2014m0915t123456.h5".
- attribute: LocalityValue
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The geographic locality of the product. Actual is "Global".
- attribute: LongName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The ESDT Long Name of the product. Actual is "OMI/Aura TOMS SO2 Vertical Column Daily L2 0.25deg Lat/Lon Grid".
- attribute: MaximumNumberOfObservationsPerGridCell
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 0
valid_max: 15
description: >
The actual maximum number of observations per cell in the L2G grid.
- attribute: MinimumNumberOfObservationsPerGridCell
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 0
valid_max: 0
description: >
The actual minimum number of observations per cell in the L2G grid. This is typically 0, because empty L2G grid cells are quite common.
- attribute: NorthBoundingCoordinate
mandatory: T
data_type: H5T_NATIVE_REAL
number_of_values: 1
valid_min: -90.0
valid_max: 90.0
description: >
The terrestrial latitude (in degrees) of the northernmost data in the L2G granule.
- attribute: NumberOfEmptyGridCells
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 0
valid_max: 4147200
description: >
The number of cells in the L2G grid that do not contain any observations.
- attribute: NumberOfGridCells
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 1
valid_max: 4147200
description: >
The total number of cells in the L2G grid.
- attribute: NumberOfLatitudes
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
description: >
The number of latitude bins in the product, which is also the size of the nLatitudes dimension. There are 720 bins from -90.0 to 90.0 degrees latitude.
- attribute: NumberOfLinesMissingGeolocation
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1,16
valid_min: 1
valid_max: 1700
description: >
The number of lines in each L2 orbit that are missing geolocation (a.k.a. number of "bad" lines in each L2 file).
- attribute: NumberOfLongitudes
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
description: >
The number of longitude bins in the product, which is also the size of the nLongitudes dimension. There are 1440 bins from -180.0 to 180.0 degrees longitude.
- attribute: NumberOfPopulatedGridCells
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 0
valid_max: 4147200
description: >
The number of cells in the L2G grid that contain one or more observations.
- attribute: NumberOfObservationsAcceptedIntoGrid
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 0
valid_max: 1500000
description: >
The number of observations accepted into the L2G grid.
- attribute: NumberOfObservationsConsideredForGrid
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 0
valid_max: 1500000
description: >
The number of observations considered for the L2G grid.
- attribute: NumberOfObservationsRejectedFromGrid
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1
valid_min: 0
valid_max: 1500000
description: >
The number of observations rejected from the L2G grid.
- attribute: OrbitalPeriod
mandatory: T
data_type: H5T_NATIVE_REAL
number_of_values: 1,16
valid_min: 5000.0
valid_max: 7000.0
description: >
The Aura orbital period for each L2 input granule.
- attribute: OrbitNumber
mandatory: T
data_type: H5T_NATIVE_INTEGER
number_of_values: 1,16
valid_min: 1
valid_max: 99999
description: >
The OMI orbit number for each L2 input granule.
- attribute: ParameterName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The measured science parameter expressed in the L2G granule. Actual is "Vertical Column Sulfur Dioxide".
- attribute: Period
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
valids: Daily,Weekly,Monthly
description: >
The duration of the L2G granule. Actual is "Daily".
- attribute: PGEVersion
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The version of the PGE or App that was used to create the product file. Example is "0.0.1".
- attribute: PlatformShortName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The Short Name of the platform. Actual is "Aura".
- attribute: ProcessingCenter
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
valids: ACPS,OMIDAPS,TLCF
description: >
The processing center where the product was created. Example is "ACPS".
- attribute: ProcessLevel
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The process level of the product. Actual is "2G".
- attribute: ProductionDateTime
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The date and time of the OMIAuraSO2G processing. Example is "2014-12-31T12:34:56.0Z".
- attribute: ProductType
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The temporal type of the product. Actual is "L2G Grid".
- attribute: RangeBeginningDate
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The UTC year, month and day when the L2G granule begins. Example is "2010-12-25".
- attribute: RangeBeginningTime
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The UTC hour, minute and second when the L2G granule begins. Example is "12:00:00".
- attribute: RangeEndingDate
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The UTC year, month and day when the L2G granule ends. Example is "2010-12-26".
- attribute: RangeEndingTime
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The UTC hour, minute and second when the L2G granule ends. Example is "13:00:00".
- attribute: SensorShortName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The Short Name of the sensor. Actual is "CCD Ultra Violet".
- attribute: ShortName
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The ESDT Short Name of the product. Actual is "OMIAuraSO2G".
- attribute: SouthBoundingCoordinate
mandatory: T
data_type: H5T_NATIVE_REAL
number_of_values: 1
valid_min: -90.0
valid_max: 90.0
description: >
The terrestrial latitude (in degrees) of the southernmost data in the L2G granule.
- attribute: StartUTC
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
UTC at the start of the L2G granule in "YYYY-MM-DDT23:59:59.999999Z" format.
- attribute: TAI93At0zOfGranule
mandatory: T
data_type: H5T_NATIVE_DOUBLE
number_of_values: 1
valid_min: -5.0e+09
valid_max: 1.0e+10
description: >
The TAI93 time (in continuous seconds since 12 a.m. UTC on January 1, 1993) at 0z of the L2G granule (see Section 6.1 of Reference 6).
- attribute: VersionID
mandatory: T
data_type: H5T_NATIVE_CHARACTER
number_of_values: 1
description: >
The Collection Version of the product. Example is "3.00".
- attribute: WestBoundingCoordinate
mandatory: T
data_type: H5T_NATIVE_REAL
number_of_values: 1
valid_min: -180.0
valid_max: 180.0
description: >
The terrestrial longitude (in degrees) of the westernmost data in the L2G granule.
Dimensions:
- dimension: nCorners
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimension_type: FIXED
units: 1
long_name: Ground Pixel Corner
description: >
The dimension representing the ground pixel corners. There are four corners per ground pixel.
- dimension: nLatitudes
mandatory: T
data_type: H5T_NATIVE_REAL
dimension_type: FIXED
units: degrees_east
long_name: Latitude
description: >
The dimension representing the terrestrial latitude at the centers of the grid cells in the product. The values are in degrees north of the equator.
- dimension: nLongitudes
mandatory: T
data_type: H5T_NATIVE_REAL
dimension_type: FIXED
units: degrees_north
long_name: Longitude
description: >
The dimension representing the terrestrial longitude at the centers of the grid cells in the product. The values are in degrees east of the International Reference Meridian.
- dimension: nObservations
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimension_type: FIXED
units: 1
long_name: Number of Observations
description: >
The dimension representing the number of observations in each L2G grid cell. The values range from 0 to 15.
ANCILLARY_DATA Group:
- dataset: CloudPressure
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0.0
valid_max: 1013.25
_FillValue: -1.2676506e+30
units: hPa
long_name: Effective Cloud Pressure
description: >
The effective cloud pressure (in hPa from OMCLDRR) associated with the ground pixel for each observation in each L2G grid cell.
- dataset: TerrainHeight
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -200
valid_max: 10000
_FillValue: -2147483647
units: m
long_name: Terrain Height
description: >
The terrain height (in m from the OMI Level 1B file) at the center of the ground pixel for each observation in each L2G grid cell.
- dataset: TerrainPressure
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0.0
valid_min: 1013.25
_FillValue: -1.2676506e+30
units: hPa
long_name: Terrain Pressure
description: >
The terrain pressure (in hPa from OMTO3) at the center of the ground pixel for each observation in each L2G grid cell.
GEOLOCATION_DATA Group:
- dataset: CrossTrackPositionNumber
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 1
valid_max: 60
_FillValue: -2147483647
units: 1
long_name: Cross-Track Position Number of Observation
description: >
The cross-track position number for each observation in each L2G grid cell.
- dataset: FoV75CornerLatitude
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nCorners,nLongitudes,nLatitudes
valid_min: -90.0
valid_max: 90.0
_FillValue: -1.2676506e+30
units: degrees_north
long_name: "Corner Latitudes for 75% Field of View Pixels on the WGS-85 Ellipsoid (CCW relative to flight direction: LL,LR,UR,UL)"
description: >
The geodetic latitudes (in degrees from OMPIXCOR) of the corner coordinates of the 75% Field of View (i.e., overlapping) ground pixels for each observation in each L2G grid cell.
- dataset: FoV75CornerLongitude
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nCorners,nLongitudes,nLatitudes
valid_min: -180.0
valid_max: 180.0
_FillValue: -1.2676506e+30
units: degrees_east
long_name: "Corner Longitudes for 75% Field of View Pixels on the WGS-85 Ellipsoid (CCW relative to flight direction: LL,LR,UR,UL)"
description: >
The geodetic longitudes (in degrees from OMPIXCOR) of the corner coordinates of the 75% Field of View (i.e., overlapping) ground pixels for each observation in each L2G grid cell.
- dataset: GroundPixelQualityFlags
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 65534
_FillValue: -2147483647
units: 1
long_name: Ground Pixel Quality Flags
description: >
The ground pixel quality flags (for the ground pixel) for each observation 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 6 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 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 7 for more details.)
- dataset: Latitude
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -90.0
valid_max: 90.0
_FillValue: -1.2676506e+30
units: degrees_north
long_name: Latitude
description: >
The terrestrial latitude (in degrees) at the center of the ground pixel for each observation in each L2G grid cell.
- dataset: Longitude
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -180.0
valid_max: 180.0
_FillValue: -1.2676506e+30
units: degrees_east
long_name: Longitude
description: >
The terrestrial longitude (in degrees) at the center of the ground pixel for each observation in each L2G grid cell.
- dataset: NumberOfObservations
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nLongitudes,nLatitudes
valid_min: 0
valid_max: 8
_FillValue: 0
units: 1
long_name: Number of Observations
description: >
The number of observations in each L2G grid cell.
- dataset: OrbitNumber
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 1
valid_max: 999999
_FillValue: -2147483647
units: 1
long_name: Orbit Number of Observation
description: >
The orbit number for each observation in each L2G grid cell.
- dataset: PathLength
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 2.0
valid_max: 100.0
_FillValue: 1.2676506e+30
units: 1
long_name: Path Length
description: >
The path length [= sec(solar zenith angle) + sec(viewing zenith angle)] for each observation in each L2G grid cell.
- dataset: RelativeAzimuthAngle
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -180.0
valid_max: 180.0
_FillValue: -1.2676506e+30
units: degrees_eastofnorth
long_name: Relative Azimuth Angle (sun + 180 - view)
description: >
The relative (sun + 180 - view) azimuth angle (in degrees) at the center of the ground pixel for each observation in each L2G grid cell.
- dataset: SecondsInDay
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0.0
valid_max: 86401.0
_FillValue: -1.2676506e+30
units: s
long_name: Seconds After UTC Midnight
description: >
The time (in s) after UTC midnight at the start of the observation for each observation in each L2G grid cell.
- dataset: SolarAzimuthAngle
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -180.0
valid_max: 180.0
_FillValue: -1.2676506e+30
units: degrees_eastofnorth
long_name: Solar Azimuth Angle
description: >
The solar azimuth angle (in degrees) at the center of the ground pixel for each observation in each L2G grid cell.
- dataset: SolarZenithAngle
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0.0
valid_max: 90.0
_FillValue: -1.2676506e+30
units: degrees
long_name: Solar Zenith Angle
description: >
The solar zenith angle (in degrees) at the center of the ground pixel for each observation in each L2G grid cell.
- dataset: SwathLineNumber
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 1
valid_max: 1700
_FillValue: -2147483647
units: 1
long_name: Swath Line Number of Observation
description: >
The swath line number for each observation scene in each L2G grid cell.
- dataset: Time
mandatory: T
data_type: H5T_NATIVE_DOUBLE
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -5.0e+09
valid_max: 1.0e+10
_FillValue: -1.2676506002282294e+30
units: seconds since 1993-01-01
long_name: Time at Start of Scan (TAI93)
description: >
The TAI93 time (in continuous seconds since 12 a.m. UTC on January 1, 1993) of the start of the "scan" for each observation in each L2G grid cell.
- dataset: ViewingAzimuthAngle
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -180.0
valid_max: 180.0
_FillValue: -1.2676506e+30
units: degrees_eastofnorth
long_name: Viewing Azimuth Angle
description: >
The viewing azimuth angle (in degrees) at the center of the ground pixel for each observation in each L2G grid cell.
- dataset: ViewingZenithAngle
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0.0
valid_max: 70.0
_FillValue: -1.2676506e+30
units: degrees
long_name: Viewing Zenith Angle
description: >
The viewing zenith angle (in degrees) at the center of the ground pixel for each observation in each L2G grid cell.
SCIENCE_DATA Group:
- dataset: AlgorithmFlag_PBL
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 12
_FillValue: -2147483647
units: 1
long_name: Algorithm Flag for PBL
description: >
The PBL processing flag for the retrieval indicating the algorithm path for each observation in each L2G grid cell:
0 - skipped
1 - linear fitting, vertical column SO2, short wavelength window
2 - linear fitting, vertical column SO2, long wavelength window
Add 10 for snow/ice.
- dataset: AlgorithmFlag_STL
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 12
_FillValue: -2147483647
units: 1
long_name: Algorithm Flag for STL
description: >
The STL processing flag for the retrieval indicating the algorithm path for each observation in each L2G grid cell:
0 - skipped
1 - linear fitting, vertical column SO2, short wavelength window
2 - linear fitting, vertical column SO2, long wavelength window
Add 10 for snow/ice.
- dataset: AlgorithmFlag_TRL
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 12
_FillValue: -2147483647
units: 1
long_name: Algorithm Flag for TRL
description: >
The TRL processing flag for the retrieval indicating the algorithm path for each observation in each L2G grid cell:
0 - skipped
1 - linear fitting, vertical column SO2, short wavelength window
2 - linear fitting, vertical column SO2, long wavelength window
Add 10 for snow/ice.
- dataset: AlgorithmFlag_TRM
mandatory: T
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 12
_FillValue: -2147483647
units: 1
long_name: Algorithm Flag for TRM
description: >
The TRM processing flag for the retrieval indicating the algorithm path for each observation in each L2G grid cell:
0 - skipped
1 - linear fitting, vertical column SO2, short wavelength window
2 - linear fitting, vertical column SO2, long wavelength window
Add 10 for snow/ice.
- dataset: ChiSquare
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0.0
valid_max: 100.0
_FillValue: -1.2676506e+30
units: 1
long_name: Chi Square of the Fitting Residuals
description: >
The Chi square for STL from the linear least squares fit for each observation in each L2G grid cell.
- dataset: ColumnAmountO3
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 50.0
valid_min: 700.0
_FillValue: -1.2676506e+30
units: DU
long_name: Best Total Ozone Solution
description: >
The best retrieved total ozone column amount from OMTO3 for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_PBL
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (PBL)
description: >
The retrieved vertical column amount SO2 with a boundary-layer SO2 profile averaged from in-situ aircraft measurements over the eastern United States for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_PBL_TOMS
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (PBL-TOMS)
description: >
The retrieved vertical column amount SO2 with a boundary-layer SO2 profile averaged from in-situ aircraft measurements over the eastern United States based on the TOMS algorithm for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_STL
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (STL)
description: >
The retrieved vertical column amount SO2 with a prescribed SO2 profile similar to the standard ozone profile in Umkher layer 3 (roughly between 15 and 20 km altitude) for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_STL_TOMS
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (STL-TOMS)
description: >
The retrieved vertical column amount SO2 with a prescribed SO2 profile similar to the standard ozone profile in Umkher layer 3 (roughly between 15 and 20 km altitude) based on the TOMS algorithm for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_TRL
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (TRL)
description: >
The retrieved vertical column amount SO2 with a prescribed SO2 profile similar to the standard ozone profile in Umkher layer 0 (roughly between 0 and 5 km altitude) for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_TRL_TOMS
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (TRL-TOMS)
description: >
The retrieved vertical column amount SO2 with a prescribed SO2 profile similar to the standard ozone profile in Umkher layer 0 (roughly between 0 and 5 km altitude) based on the TOMS algorithm for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_TRM
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (TRM)
description: >
The retrieved vertical column amount SO2 with a prescribed SO2 profile similar to the standard ozone profile in Umkher layer 1 (roughly between 5 and 10 km altitude) for each observation in each L2G grid cell.
- dataset: ColumnAmountSO2_TRM_TOMS
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -10.0
valid_min: 2000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Vertical Column Amount SO2 (TRM-TOMS)
description: >
The retrieved vertical column amount SO2 with a prescribed SO2 profile similar to the standard ozone profile in Umkher layer 1 (roughly between 5 and 10 km altitude) based on the TOMS algorithm for each observation in each L2G grid cell.
- dataset: deltaO3
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -1000.0
valid_min: 1000.0
_FillValue: -1.2676506e+30
units: DU
long_name: Ozone Adjustment from Least-Squares Fit
description: >
The ozone adjustment derived from the least-squares fitting method for each observation in each L2G grid cell.
- dataset: deltaRefl
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -1.0
valid_min: 1.0
_FillValue: -1.2676506e+30
units: 1
long_name: Adjustment to Reflectivity at 331 nm
description: >
The reflectivity vs. wavelength is described by a second order polynomial, R = R331 + c1*(lambda-331) + c2 *(lambda-331)**2. The deltaRefl is the reflectivity adjustment to the zeroeth order term, R331, for each observation in each L2G grid cell.
- dataset: QualityFlags_PBL
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 8191
_FillValue: -2147483647
units: 1
long_name: Quality Flags for PBL
description: >
The quality flags PBL for the retrieval for each observation in each L2G grid cell. Each bit corresponds to a flag that
is set to 0 for good value, or 1 for bad value:
Bit 0 - SO2 consistency flag (0 for SO2 from 3 pairs are consistent, 1 for not)
Bit 1 - geometric slant O3 column >= Threshold (currently set at 1500 D.U.)
Bit 2 - UV Aerosol Index > 3
Bit 3 - Reflectivity at 331 nm > 15%
Bit 4 to 6 together represents one number with a value ranging from 0 to 7, and
is equal to the first 4 bits of the OMTO3 QualityFlags.
Bit 7 - Descending
Bit 8 - reflectivity error
Bit 9 - geolocation error
Bit 10 - L1B warning, error, or missing
Bit 11 - set to be same as bit 6 of the OMTO3 QualityFlags
Bit 12 - set to be same as bit 7 of the OMTO3 QualityFlags
Bit 13 - place holder, set to zero currently
Bit 14 - place holder, set to zero currently
Bit 15 - place holder, set to zero currently
- dataset: QualityFlags_STL
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 8191
_FillValue: -2147483647
units: 1
long_name: Quality Flags for STL
description: >
The quality flags STL for the retrieval for each observation in each L2G grid cell. Each bit corresponds to a flag that
is set to 0 for good value, or 1 for bad value:
Bit 0 - SO2 consistency flag (0 for SO2 from 3 pairs are consistent, 1 for not)
Bit 1 - geometric slant O3 column >= Threshold (currently set at 1500 D.U.)
Bit 2 - UV Aerosol Index > 3
Bit 3 - Reflectivity at 331 nm > 15%
Bit 4 to 6 together represents one number with a value ranging from 0 to 7, and
is equal to the first 4 bits of the OMTO3 QualityFlags.
Bit 7 - Descending
Bit 8 - reflectivity error
Bit 9 - geolocation error
Bit 10 - L1B warning, error, or missing
Bit 11 - set to be same as bit 6 of the OMTO3 QualityFlags
Bit 12 - set to be same as bit 7 of the OMTO3 QualityFlags
Bit 13 - place holder, set to zero currently
Bit 14 - place holder, set to zero currently
Bit 15 - place holder, set to zero currently
- dataset: QualityFlags_TRL
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 8191
_FillValue: -2147483647
units: 1
long_name: Quality Flags for TRL
description: >
The quality flags TRL for the retrieval for each observation in each L2G grid cell. Each bit corresponds to a flag that
is set to 0 for good value, or 1 for bad value:
Bit 0 - SO2 consistency flag (0 for SO2 from 3 pairs are consistent, 1 for not)
Bit 1 - geometric slant O3 column >= Threshold (currently set at 1500 D.U.)
Bit 2 - UV Aerosol Index > 3
Bit 3 - Reflectivity at 331 nm > 15%
Bit 4 to 6 together represents one number with a value ranging from 0 to 7, and
is equal to the first 4 bits of the OMTO3 QualityFlags.
Bit 7 - Descending
Bit 8 - reflectivity error
Bit 9 - geolocation error
Bit 10 - L1B warning, error, or missing
Bit 11 - set to be same as bit 6 of the OMTO3 QualityFlags
Bit 12 - set to be same as bit 7 of the OMTO3 QualityFlags
Bit 13 - place holder, set to zero currently
Bit 14 - place holder, set to zero currently
Bit 15 - place holder, set to zero currently
- dataset: QualityFlags_TRM
data_type: H5T_NATIVE_INTEGER
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0
valid_max: 8191
_FillValue: -2147483647
units: 1
long_name: Quality Flags for TRM
description: >
The quality flags TRM for the retrieval for each observation in each L2G grid cell. Each bit corresponds to a flag that
is set to 0 for good value, or 1 for bad value:
Bit 0 - SO2 consistency flag (0 for SO2 from 3 pairs are consistent, 1 for not)
Bit 1 - geometric slant O3 column >= Threshold (currently set at 1500 D.U.)
Bit 2 - UV Aerosol Index > 3
Bit 3 - Reflectivity at 331 nm > 15%
Bit 4 to 6 together represents one number with a value ranging from 0 to 7, and
is equal to the first 4 bits of the OMTO3 QualityFlags.
Bit 7 - Descending
Bit 8 - reflectivity error
Bit 9 - geolocation error
Bit 10 - L1B warning, error, or missing
Bit 11 - set to be same as bit 6 of the OMTO3 QualityFlags
Bit 12 - set to be same as bit 7 of the OMTO3 QualityFlags
Bit 13 - place holder, set to zero currently
Bit 14 - place holder, set to zero currently
Bit 15 - place holder, set to zero currently
- dataset: RadiativeCloudFraction
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: 0.0
valid_max: 1.0
_FillValue: -1.2676506e+30
units: 1
long_name: Radiative Cloud Fraction = fc*lc331/lm331
description: >
The radiative cloud fraction (= fc * lc331 / lm331) associated with the retrieval for each observation in each L2G grid cell.
- dataset: Reflectivity331
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -15.0
valid_max: 115.0
_FillValue: -1.2676506e+30
units: "%"
long_name: Effective Surface Reflectivity at 331 nm
description: >
Effective surface reflectivity of the surface at 331 nm associated with the retrieval for each observation in each L2G grid cell.
- dataset: Rlambda1st
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -1.0
valid_max: 1.0
_FillValue: -1.2676506e+30
units: 1
long_name: First Order Term of R-Lambda Function
description: >
The reflectivity vs. wavelength is described by a second order polynomial, R = R331 + c1*(lambda-331) + c2 *(lambda-331)**2. Rlambda1st is the first order coefficient c1 for each observation in each L2G grid cell.
- dataset: Rlambda2nd
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -1.0
valid_max: 1.0
_FillValue: -1.2676506e+30
units: 1
long_name: Second Order Term of R-Lambda Function
description: >
The reflectivity vs. wavelength is described by a second order polynomial, R = R331 + c1*(lambda-331) + c2 *(lambda-331)**2. Rlambda2nd is the second order coefficient c2 for each observation in each L2G grid cell.
- dataset: UVAerosolIndex
mandatory: T
data_type: H5T_NATIVE_REAL
dimensions: nObservations,nLongitudes,nLatitudes
valid_min: -50.0
valid_max: 50.0
_FillValue: -1.2676506e+30
units: 1
long_name: UV Aerosol Index
description: >
The UV aerosol index associated with the retrieval for each observation in each L2G grid cell.
Core Metadata: None.
Product Specific Attributes: None.
Archived Metadata: None.
References: >
1. "OMSO2 README File"
(18 August 2008)
(http://disc.sci.gsfc.nasa.gov/Aura/data-holdings/OMI/omso2_v003.shtml)
2. "OMTO3 README File"
(3 April 2012)
(http://disc.sci.gsfc.nasa.gov/Aura/data-holdings/OMI/omto3_v003.shtml)
3. "Definition of OMI Grids for Level 3 and Level 4 Data Products"
(OMI-Grids_L3L4, SD-OMIE-KNMI-443, 25 January 2005)
4. "ICD Between GES DISC S4PA and Multi-Decadal Sulfur Dioxide Climatology from Satellite Instruments/Nickolay Krotkov"
Prepared by James Johnson
Revised December 31, 2013
5. "MEaSUREs Data at the GES DISC: Recommendations to Data Providers"
Prepared by Dana Ostrenga, James Johnson, and Bruce Vollmer
Revised June 27, 2011
6. "A File Format for Satellite Atmospheric Chemistry Data Based on Aura File Format Guidelines"
Craig, C., Veefkind, P., Leonard, P., Wagner, P., Vuu, C., and Shepard, D.
ESDS-RCF-009, May 2008
http://www.esdswg.org/spg/rfc/esds-rfc-009/ESDS-RFC-009.pdf/view
7. "OMI GDPS Input/Output Data Specification (IODS) Volume 2"
(OMI-GDPS-IODS-2, SD-OMIE-7200-DS-467, 9 April 2003)
