In this study the correlation between OMI tropospheric NO2 and cloud physical parameters was investigated, motivated by the idea to use OMI NO2 as a proxy for AOT in observing the aerosol indirect effect. OMI NO2 observations were compared to MODIS AOT and cloud physical parameters from SEVIRI and PATMOS-x over Europe, Africa and China. No clear correlation is found in the daily observations, but for monthly averaged measurements higher NO2 values correspond to smaller SEVIRI r_e over eastern Europe and the Po-valley, the decrease of re levels off for NO2 columns exceeding 3x10^15 molecules/cm2. Over China and selected biomass burning regions in Africa higher NO2 values correlate with smaller monthly averaged r_e observations from PATMOS-x, although in case of Africa this relation can also result from climatology as biomass burning predominantly occurs in summer.
R Dirksen, JF Meirink. Studying aerosol indirect effects by combining CM-SAF cloud microphysical property data with NO2 retrievals