The Comparison of SO2 and NO2 Removal Rates under Clear and Partly Cloudy Conditions in the Wintertime over the Eastern United States

We will examine how the rate of SO₂ and NOx removal is accentuated by the presence of clouds and aerosols under winter time conditions in the Eastern US. This will be done by quantifying the amount of cloud exposure and evaluating the loss rate under cloudy conditions and determining if it is statistically different from the clear-sky removal rate of 0.22-0.71 %/hr that we previously determined. Additionally, while some clear-sky night flights exhibited no SO₂ removal, others were commensurate with daytime removal. The aerosol characteristics such as acidity, chemical composition will be explored to determine possible condensed-phase reactions that can explain this reactivity. This is done using data based on measurements taken during a series of night and day flights on a C-130 aircraft from Feb 3 to Mar 13, 2015 over the Eastern coastal region of the United States during the Wintertime INvestigation of Transport, Emission and Reactivity (WINTER) campaign.