Dry Particulate Nitrate Deposition in China

A limited number of ground measurements of dry particulate nitrate deposition (NO₃^-) makes it difficult and challenging to fully know the status of the spatial and temporal variations of dry NO₃^- depositions over China. This study tries to expand the ground measurements of NO₃^- concentrations at monitoring sites to a national scale, based on the Ozone Monitoring Instrument (OMI) NO₂ columns, NO₂ profiles from an atmospheric chemistry transport model (Model for Ozone and Related chemical Tracers, version 4, MOZART-4) and monitor-based sources, and then estimates the NO₃^- depositions on a regional scale based on an inferred model. The ground NO₂ concentrations were first derived from NO₂ columns and the NO₂ profiles, and then the ground NO₃^- concentrations were derived from the ground NO₂ concentrations and the relationship between NO₂ and NO₃^- based on Chinese Nationwide Nitrogen Deposition Monitoring Network (NNDMN). This estimated dry NO₃^- depositions over China will be helpful in determining the magnitude and pollution status in regions without ground measurements, supporting the construction plan of environmental monitoring in future.