Summary

Description

The reprocessed OMI/Aura Level-2G cloud data product OMCLDO2G, is now available (http://disc.gsfc.nasa.gov/Aura/OMI/omcldo2g_v003.shtml) from the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) for the public access. It is the second release of V003 and was reprocessed late 2011. (The shortname for this Level-2G OMI cloud product is OMCLDO2G) 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 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 and Ozone, Ring coefficients, uncertainties in derived parameters, terrain and geolocation information, solar and satellite viewing angles, and quality flags. The short name for this Level-2 OMI cloud product is OMCLDO2G and the lead scientist for this product and for OMCLDO2 (the data source of OMCLDO2G) is KNMI scientist Dr.Pepijn Veefkind. OMCLDO2G data product is a special Level-2 Global Gridded Product where pixel level data (OMCLDO2) are binned into 0.25x0.25 degree global grids. It contains the OMCLDO2 data for all L2 scenes that have observation time between UTC times of 00:00:00 and 23:59:59.9999. All data pixels that fall in a grid are saved 'Without Averaging'. Scientists can apply data filtering scheme of their choice and create new gridded products. OMCLDO2G product files are stored in Hierarchical Data Format(HDF-EOS5). Each daily data file contains data from the day lit portion of the orbits (~14 orbits) and is roughly 85 MB in size. The GES DISC developed interactive tool Giovanni (http://giovanni.gsfc.nasa.gov/) provides on-line web based capabilities to browse and explore these data. Data Category and Parameters: The OMCLDO2G data file consists of a Grid Data Object which contains complete information of each pixel binned into the grid. Cloud Parameters: Cloud Fraction, Cloud Pressure (and Precisions) Ancillary Data: Terrain Pressure, Terrain Height, Terrain Reflectivity, Continuum at Reference Wave Length, Ring Coefficient Slant Column Amount O2-O2 Quality Flags: Ground Pixel Quality Flags, Measurement Quality Flags, Processing Quality Flags, Root Mean Square Error of Fit Time and Geolocation Data: Time, Latitude, Longitude, Solar Zenith Angle, Solar Azimuth Angle, Viewing Zenith Angle, Viewing Azimuth Angle, Line Number, Scene Number, Number of Candidate Scenes, Path Length, Orbit Number, Spacecraft Info (altitude, latitude, longitude)