BErkeley High Resolution (BEHR) OMI NO2 Prototype High Temporal Resolution Product

The BErkeley High Resolution (BEHR) OMI NO2 Prototype High Temporal Resolution Product makes use of high spatial and temporal resolution a priori NO2 profiles for a limited domain in the southeast United States, covering 1 June-30 Aug 2013. These retrievals have been used to evaluate the impact of daily temporal resolution of the high-spatial-resolution a priori NO2 profiles needed for the retrieval

Methods
Tropospheric slant columns are obtained from the NASA OMI Standard Product v2.1 (SP2). Tropospheric air mass factors (AMFs) are computed using the scattering weights from the SP2 look up table and a priori NO2 profiles simulated with WRF-Chem at 12 km spatial resolution. Inputs to the scattering weight look up table are the sun-satellite geometry, surface albedo from the MODIS combined black-sky albedo product (MCD43C3) and the terrain heights from the Global Land One-km Base Elevation (GLOBE) project database (https://www.ngdc.noaa.gov/mgg/topo/globe.html). The AMF for each pixel is the average of clear and cloudy AMFs; weighted by the cloud radiance fraction for that pixel. Cloudy AMFs use the OMI O2-O2 cloud pressure as the surface pressure and 0.8 as the cloud albedo. These AMFs are used to compute the BEHR tropospheric vertical column densities (VCDs).