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Description

The OMI/Aura Sulphur Dioxide (SO2) Total Column 1-orbit L2 Swath 13x24 km (OMSO2) data product has been updated with a principal component analysis (PCA)-based algorithm (v2) with new SO2 Jacobian lookup tables and a priori profiles that significantly improve retrievals for anthropogenic SO2. The data files (or granules) contain different estimates of the vertical column density (VCD) of SO2 depending on the users investigating anthropogenic or volcanic sources. Files also contain quality flags, geolocation and other ancillary information. The lead scientist for the OMSO2 product is Can Li.

The OMSO2 files are stored in the version 5 EOS Hierarchical Data Format (HDF-EOS5). Each file contains data from the daylit half of an orbit (~53 minutes). There are approximately 14 orbits per day. The resolution of the data is 13x24 km2 at nadir, with a swath width of 2600 km and 60 pixels per scan line every 2 seconds.

Product Summary

Platforms
Aura
Instruments
OMI
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2004-10-01 to Present
Data Partner
Goddard Earth Sciences Data and Information Services Center (formerly Goddard DAAC), Terrestrial Information Systems Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/TISL/GESDI
Concept ID
C3454342607-GES_DISC
Data State
ACTIVE
Number of Files/Granules
109202
Processing Level
2
Published
Updated
Science Keywords
Sulfur Dioxide

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Krotkov, N. A., & Li, C. (2025). OMI/Aura Sulphur Dioxide (SO2) Total Column 1-orbit L2 Swath 13x24 km [Data set]. NASA Goddard Earth Sciences Data and Information Services Center. https://doi.org/10.5067/AURA/OMI/DATA2422 Date Accessed: 2025-12-13

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/AlgorithmFlag_SnowIce Snow-Ice Algorithm Flag 1 uint8 255 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/CloudFraction Effective Cloud Fraction (from OMCLDRR) 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/CloudPressure Optical Centroid Pressure (from OMCLDRR) hPa float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/CloudRadianceFraction Cloud Radiance Fraction at 313 nm 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ColumnAmountO3 Best Total Ozone Solution (from OMTO3) DU float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ColumnAmountSO2 Vertical Column Amount SO2 (GEOS-5 Profile) DU float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ColumnAmountSO2_PBL Vertical Column Amount SO2 (PBL, Fixed Profile) DU float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ColumnAmountSO2_STL Vertical Column Amount SO2 (STL, Fixed Profile) DU float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ColumnAmountSO2_TRL Vertical Column Amount SO2 (TRL, Fixed Profile) DU float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ColumnAmountSO2_TRM Vertical Column Amount SO2 (TRM, Fixed Profile) DU float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ColumnAmountSO2_TRU Vertical Column Amount SO2 (TRU, Fixed Profile) DU float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/Flag_RowAnomaly OMTO3 Row-Anomaly Flag 1 uint8 255 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/Flag_SAA South Atlantic Anomaly Flag 1 uint8 255 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/GEOS5LayerWeight GEOS-5 Layer Weight 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/LayerBottomPressure Layer Bottom Pressure hPa float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/PBLLayerWeight PBL Layer Weight 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/RadiativeCloudFraction Radiative Cloud Fraction at 313 nm 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/Reflectivity342 Simple Lambertian Equivalent Reflectivity at 342 nm 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/RootMeanSquareFittingResiduals Root Mean Square of Fitting Residuals in N-value 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/ScatteringWeight Scattering Weight at 313 nm 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/SceneReflectivity354 Scene Reflectivity at 354 nm (from OMCLDRR) 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/SlantColumnAmountSO2 Slant Column Amount SO2 molecules/cm2 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/SurfaceReflectivity Surface Reflectivity at 360 nm (from OMCLDRR) 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/TerrainPressure Terrain Pressure hPa float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Data Fields/VolcanicAshIndex Volcanic Ash Index (342.5-367 nm) 1 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/GroundPixelArea Ground Pixel Area km2 float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/GroundPixelQualityFlags Ground Pixel Quality Flags 1 uint16 65535 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/Latitude Geodetic Latitude degrees_north float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/Longitude Geodetic Longitude degrees_east float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/RelativeAzimuthAngle Relative Azimuth Angle (sun + 180 - view) degrees float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/SecondsInDay Seconds After UTC Midnight s float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/SolarAzimuthAngle Solar Azimuth Angle (East of North) degrees float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/SolarZenithAngle Solar Zenith Angle degrees float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/SpacecraftAltitude Spacecraft Altitude m float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/SpacecraftLatitude Spacecraft Latitude degrees_north float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/SpacecraftLongitude Spacecraft Longitude degrees_east float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/TerrainHeight Terrain Height m int16 -32767 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/TiledCornerLatitude Tiled Corner Latitude (from L1B) degrees_north float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/TiledCornerLongitude Tiled Corner Longitude (from L1B) degrees_east float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/Time Time of Scan (TAI93) seconds since 1993-01-01 00:00:00 float64 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/ViewingAzimuthAngle Viewing Azimuth Angle (East of North) degrees float32 -1.2676506002282E+30 N/A N/A
HDFEOS/SWATHS/OMI Total Column Amount SO2/Geolocation Fields/ViewingZenithAngle Viewing Zenith Angle degrees float32 -1.2676506002282E+30 N/A N/A
HDFEOS INFORMATION/ArchivedMetadata HDFEOS INFORMATION/ArchivedMetadata N/A OTHER N/A N/A N/A
HDFEOS INFORMATION/CoreMetadata HDFEOS INFORMATION/CoreMetadata N/A OTHER N/A N/A N/A
HDFEOS INFORMATION/StructMetadata.0 HDFEOS INFORMATION/StructMetadata.0 N/A OTHER N/A N/A N/A
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