OMMYDCLD: Merged OMI and MODIS Cloud Product for A-Train Synergy

Approximately 14 orbital files per day provide merged cloud parameters from the OMI instrument on Aura and MODIS on Aqua, both satellites in the NASA A-Train constellation. This Level-2 swath product collocates daytime MODIS cloud statistics onto OMI's 13x24 km visible pixels for near-simultaneous, multi-spectral observation. It is designed for applications exploiting the synergy between the two instruments' complementary measurements.

Use Cases

• Cloud-clearing of atmospheric trace gas retrievals based on collocated MODIS statistical information.
• Detection of multi-layered cloud structures using multi-spectral measurements from OMI and MODIS.
• Analysis of cloud microphysical properties like optical depth and liquid water from the merged parameter set.
• Studying cloud radiative forcing and emissivity through combined OMI and MODIS radiative transfer data.
• Validation and improvement of cloud retrieval algorithms by leveraging the A-Train's near-simultaneous observations.

Strengths

• Provides direct synergy from two major NASA instruments (OMI and MODIS) flying in the A-Train for near-simultaneous data.
• Algorithm developed under the lead of a named NASA OMI scientist, Dr. Joanna Joiner.
• Each orbital file covers the sunlit portion (about 53 minutes) of observation, with a consistent daily cadence.

Limitations

• Conflicting technical specifications exist between sources: one states files are ~8 MB in HDF-EOS5 format, another states ~50 MB in netCDF format.
• Column names and a complete data schema are not provided in any source, limiting immediate understanding of the data structure.
• The license is specified only as 'other-license-specified' without detailed terms.

Provenance

Source

NASA Goddard Earth Sciences Data and Information Services Center (GES DISC)

Collection Method

Satellite remote sensing data from the Ozone Mapping Instrument (OMI) on Aura and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Aqua, algorithmically collocated.

Time Range

null

Freshness

2026-04-09 23:29:47.240454

Geography

Global coverage from sunlit satellite swaths.