NO2 levels over Central and South America are relatively low as compared to North America, Western Europe, and Eas Asia. Levels over most cities increased a little (< 20%). The most notable regional decrease occurred over the Brazilian Amazon (e.g., the Brazilian states of Rondônia, Mato Grosso, and Pará) in areas which have undergone deforestation in the last few decades. This decrease in NO2 levels occurred as deforestation rates in 2013 were about a third of those in 2005, steadily declining from 2005 to 2016.
Jeff Schmaltz, MODIS Rapid Response Team, NASA/GSFC