Introduction to OMI NO2 measurements
- Last update of README file and Release Notes: February 2009
- Total and tropospheric NO2 columns from OMI measurements are public released at the GES-DISC.
- Near-real-time images of total and tropospheric column amounts are available at the TEMIS website.
|Short name||Long name|
|OMNO2||OMI/Aura Nitrogen Dioxide (NO2) Total & Troposph.Column 1-Orbit L2 Swath 13x24km|
The NO2 column densities are retrieved by first fitting the spectroscopic features in the measured radiances to get slant columns. The slant column is converted into the vertical column using air mass factor (AMF) which is calculated using a radiative transfer model and assumed vertical profile.
Next, stratosphere NO2 columns are estimated from the column data by first removing data over polluted areas and spatially filtering the rest of the data. OMI-derived tropospheric NO2 columns track NO2 pollution near the surface, which is an important precursor of urban smog.
A level-4 near-real-time (NRT) product is produced from the NO2 slant columns and assimilated NO2 profile shapes. This NRT product contains the total NO2 column and the tropospheric NO2 column and is available within 3 hours after observation at the TEMIS website.