The Level-2 Aura Ozone Monitoring Instrument (OMI) Cloud Pressure and Fraction (O2-O2 Absorption) Product (OMCLDO2) version 4 is now available from NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) for public access. The data was re-processed in December 2022 using collection 4 Level 1b data and the OMCLDO2 processor version 4.0.0. Since then, this version of the product is also being produced in the forward stream. This version of the product was publicly released in March 2026.

OMI provides two cloud products based on two different algorithms, the Rotational Raman Scattering method, and O2-O2 absorption method using the DOAS technique. This level-2 global cloud product, with a pixel resolution of 13x24 km2 at nadir, is based on the spectral fitting of O2-O2 absorption band at 477 nm using DOAS technique. This product contains cloud pressure, cloud fraction, slant column O2-O2, ozone, ring coefficients, uncertainties in derived parameters, terrain and geolocation information, solar and satellite viewing angles, and quality flags. The lead scientist for this product is Dr. Pepijn Veefkind.

The OMCLDO2 files are stored in netCDF 4 format. Each file contains data from the day lit portion of an orbit (~53 minutes). There are approximately 14 orbits per day. The maximum file size for the OMCLDO2 data product is about 13 Mbytes.