An Overview of Striking Scientific Applications of Nitrogen Dioxide Retrievals from the Ozone Monitoring Instrument Between 2004 and 2014

Abstract:

Nitrogen oxides are involved in many atmospheric processes relevant to air pollution, climate change, and environmental stress. Gaseous nitrogen oxides are toxic, regulated by regional authorities and the WHO, and their emissions and chemistry are important for the formation of ozone and aerosols. Nitrogen oxides are thought to act as a net climate cooler, mostly via enhancing the oxidative capacity of the global troposphere resulting in CH₄ lifetime reductions, and via the formation of light-scattering particles. In this paper I will discuss how tropospheric NO₂ column retrievals from the Ozone Monitoring Instrument on board EOS-Aura have pushed the envelope in various scientific applications over the last decade. A categorization of these applications shows that OMI NO₂ data have been used for (1) high-resolution monitoring of NO_x emissions, (2) monitoring trends in NO₂ air pollution levels, (3) evaluating mid-day NO_x chemistry, (4) evaluating secondary pollutant formation, (5) estimating surface NO₂ concentrations, (6) improving forecasting skills of air quality and chemistry transport models, (7) estimating nitrogen deposition to ecosystems, and (8) outreach activities to the general public. I will show some intriguing examples of the above applications, and pay close attention to the steps necessary to arrive at these successful applications. These steps include advanced filtering of the data for e.g. wind direction or speed, spatial pattern recognition to isolate specific emission categories, and more generally improving the description of NO_x emission categories and chemistry in models at spatial and temporal scales relevant to OMI and upcoming TROPOMI and geostationary sensors.