BErkeley High Resolution (BEHR) OMI NO2 Prototype High Temporal Resolution Product
Creators: name: Laughner, Joshua
Publisher: name: Dryad
publisherIdentifier: https://ror.org/00x6h5n95
publisherIdentifierScheme: ROR
Year: 2016
Subjects: BEHR
Berkeley High Resolution NO2
nitrogen dioxide
NO2
OMI
ozone monitoring instrument

description: 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
description: 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).
description: There are nine .zip archives containing retrievals for the period 1
 June-30 Aug 2013. The three .zip files marked "pseudo" contain
 pseudo-retrievals for this period; these retrievals use the same set of
 OMI pixels for all days. Thus, VCDs are not included in these files, only
 the BEHR AMFs. The purpose is to show the impact of daily vs. NO2 profiles
 on the AMFs. The three pseudo-retrieval zip archives differ only in the
 NO2 profiles used: daily profiles, monthly average profiles, or hybrid
 profiles, which use daily profiles below 750 hPa and monthly average
 above. The other six .zip archives (marked "prototype") contain
 full retrievals with the actual pixels for each day. Again, three
 different sets of NO2 a priori profiles are used, daily, monthly average,
 and coarse monthly average profiles (simulated at 108 km spatial
 resolution). The "native" files contain data at the native OMI
 pixel resolution; the "gridded" files contain this data
 oversampled to a 0.05x0.05 degree grid. The latter is easier to average
 over time, since the geographic coordinates of each grid cell is fixed
 from day to day. This data should be filtered for quality by the
 vcdQualityFlags and XTrackQualityFlags fields. Only pixels where
 vcdQualityFlags is an even integer and XTrackFlags is 0 should be used.
 Cloud filtering is also recommended for most applications; we require that
 CloudFraction is less than or equal to 0.2. Although the full prototype
 retrievals contain pixels throughout the continental US, only pixels
 within the approximate domain 89 to 79 deg. W and 30 to 38 deg. N have
 valid data.