Improvement on OMI Ozone Profile Retrievals and Validation With Ozonesonde Observations

An ozone profile algorithm has been developed to retrieve ozone profile including tropospheric ozone from OMI ultraviolet measurements. Ozone profiles are retrieved in 24 layers from the surface to ~60 km with retrieval precision generally ranging from 0.5-2% in the middle stratosphere to within 10% in the troposphere. The retrieved tropospheric ozone has sufficient accuracy to see ozone perturbations caused by convection, biomass burning and anthropogenic pollution, and to track their transport spatiotemporally. Tropospheric, stratospheric and total ozone columns can be accurately retrieved to typically within the few Dobson unit ranges. In this study, we further optimize ozone profile retrievals including improved slit function characterization, solar irradiances, fitting window, Ring correction, forward model simulation, radiometric calibration, and ozone profile climatology. Monthly mean solar irradiances rather than a 3-year average solar irradiance are used to reduce the effects of instrument degradation on retrievals. Retrievals in the upper troposphere and lower stratosphere are significantly improved by using a tropopause-based ozone profile climatology and tropopause height from NCEP FNL (Final) operational global analysis. The improved retrievals are compared with available ozonesonde observations during the 2004-2010 time period with a focus on the retrievals in the troposphere and lower stratosphere.