Summary

Description

The Version-3 Aura-OMI Formaldehyde Product OMHCHOG is now available (http://disc.gsfc.nasa.gov/Aura/OMI/omhchog_v003.shtml) from the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) for the public access. (The shortname for this Level-2G OMI total column Formaldehyde product is OMHCHOG) The algorithm leads for this product are the US OMI scientists Dr. Kelly Chance (kchance@cfa.harvard.edu) and Dr. Thomas Kurosu (tkurosu@cfa.harvard.edu) from the Harvard-Smithsonian Center, Cambridge, MA. OMHCHOG data product is a special Level-2 Global Gridded Product where pixel level data are binned into 0.25x0.25 degree grids. It contains data for all L2 scenes that have observation time betweeen UTC times of 00:00:00 and 23:59:59.9999. All data pixels that fall in a grid box are saved without Averaging (third dimension provides indexing for the data points in each small grid). Scientist can apply data filtering scheme of their choice and create Level-3 global gridded products. The GES DISC developed interactive tool Giovanni( http://giovanni.gsfc.nasa.gov/ ) provides on-line web based capabilities to browse and explore the Level-2G data. The OMHCHOG data product contains almost all parameters (e.g. total vertical column HCHO, standard erros, quality flags, geolocation and ancillary information) that are contained in the OMHCHO product. OMHCHOG data are stored in EOS Hierarchical Data Format (HDF-EOS5). Each file contains data from the day lit portions of 14 to 15 orbits that cover the globe in a day. The average file size for the OMGCHOG data product is about 55 Mbytes. A list of tools for browsing and extracting data from these files can be found at: http://disc.gsfc.nasa.gov/Aura/tools.shtml A short Readme Document giving brief algorithm description and documents containing known data quality related issues for the OMHCHO product (the source of OMHCHOG data)are available from the GES DISC site( http://disc.gsfc.nasa.gov/Aura/OMI/omhchog_v003.shtml )