TY - JOUR A1 - Russell, A. R. A1 - Valin, L. C. A1 - Cohen, R. C. T1 - Trends in OMI NO2 observations over the United States: effects of emission control technology and the economic recession JO - Atmos. Chem. Phys. J1 - ACP VL - 12 IS - 24 SP - 12197 EP - 12209 Y1 - 2012/12/21 PB - Copernicus Publications SN - 1680-7324 UR - http://www.atmos-chem-phys.net/12/12197/2012/ L1 - http://www.atmos-chem-phys.net/12/12197/2012/acp-12-12197-2012.pdf DO - 10.5194/acp-12-12197-2012 ER -