“…Satellite-based estimates of NO 2 columns have been widely used in studies of atmospheric chemistry, air quality, and climate (greenhouse gas trends and lifetimes), and in the evaluation of chemistry transport models (CTMs). In the stratosphere, satellite-based NO 2 observations have been used to study factors influencing ozone loss and recovery [e.g., Adams et al, 2013] as well as long-term trends in stratospheric composition [e.g., Dirksen et al, 2011, Hendrick et al, 2012. In the troposphere, satellite NO 2 records show the sources [van der A et al, 2008;Lin et al, 2010;Ghude et al, 2013;Mebust et al, 2011;Mebust and Cohen, 2013], spatial patterns [Martin et al, 2003;Toenges-Schuller et al, 2006;Russell et al, 2010;Hilboll et al, 2013a], and trends of NO x emissions [Richter et al, 2005;Kim et al, 2006;Zhang et al, 2007;Boersma et al, 2008;McLinden et al, 2012;de Wildt et al, 2012;Russell et al, 2012;Duncan et al, 2013;Streets et al, 2013;Vinken et al, 2014], NO x lifetimes [Schaub et al, 2007;Lamsal et al, 2010;Beirle et al, 2011], and the impact of population and economic activity on NO x emissions .…”