Inferring the anthropogenic NO<sub><i>x</i></sub> emission trend over the United States during 2003–2017 from satellite observations: was there a flattening of the emission trend after the Great Recession?

. We illustrate the nonlinear relationships among anthropogenic NOx emissions, NO2 tropospheric vertical column densities (TVCDs), and NO2 surface concentrations using model simulations for July 2011 over the contiguous United States (CONUS). The variations in NO2 surface concentrations and TVCDs are generally consistent and reflect anthropogenic NOx emission variations for high anthropogenic NOx emission regions well. For low anthropogenic NOx...