We determine NOx
emissions for Paris in summer 2009 and winter 2009/2010 by combining car MAX-DOAS measurements with wind fields to determine the total NOx
emission from the city. We compare the results with simulations from the CHIMERE model. We derive daily average NOx
emissions for Paris of 4.2 × 1025
molecules/s for summer and of 7.8 × 1025
molecules/s in winter. These values are by a factor of about 1.4 and 2.0 larger than the corresponding emissions in the MACC-III emission inventory.