An intercomparison of satellite-derived ground-level NO2 concentrations with GMSMB modeling results and in-situ measurements - A North American study

This paper investigates the biases associated with the ground-level nitrogen dioxide (NO2) concentrations derived from the satellite Ozone Monitoring Instrument (OMI) NO2 data through comparisons with the modeling and the monitoring results for the state of California in 2008. The seasonal and annual average ground-level NO2 concentrations are both analyzed from the OMI using the local NO2 profile obtained from the GEOS-Chem simulation. The OMI-derived ground-level NO2 concentrations are then compared with the NO2 concentrations predicted by a GIS-Based Multi-Source and Multi-Box model (GMSMB) and the in-situ measurements, correlation coefficients among the three sets of results are all above 0.84 with an average slope of 0.81 ± 0.04. Particularly, various biases associated with the three data sets have been analyzed, and the OMI-derived NO2 concentrations and the GMSMB modeling results have been proven to be essential for assessing regional air pollutant exposure risks with the aid of the extensive remote sensing database.