Application of Aura OMI L2G Products Compared with NASA MERRA-2 Assimilation

Ozone Monitoring Instrument (OMI) is one of the instruments aboard NASA's Aura mission. It measures ozone total column and vertical profile, aerosols, clouds, and the trace gases including NO₂, SO₂, HCHO, BrO, and OClO using UltraViolet electromagnetic spectrum (280 - 400 nm) . OMI Level-2G (L2G) products are based on the pixel level OMI granule satellite measurements storing within the global 0.25º × 0.25º grids, therefore they are conserving all the Level-2 (L2) spatial and temporal details of 24 hours scientific data in one file. The second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) is NASA's atmospheric reanalysis using an upgraded version of Goddard Earth Observing System Model, version 5 (GEOS-5) data assimilation system. MERRA-2 includes aerosol data reanalysis and improved representations of stratosphere ozone, compared with its predecessor MERRA, in instantaneous and time-averaged collections. It is found that simply comparing satellite Level-3 products might cause biases due to lack of detailed temporal and original retrieval information and it has been preferred to inter-compare or implement satellite derived physical quantity directly with/to model assimilation with higher temporal and spatial resolution as possible. This study will demonstrate the utilization of OMI L2G daily aerosol and ozone products by comparing with MERRA-2 hourly aerosol/ozone simulations matched in both space and time aspects.

Both OMI and MERRA-2 products are accessible online through NASA Goddard Earth Sciences Data Information Services Center (GES DISC).