Distribution of Tropospheric Ozone during DISCOVER-AQ July 2011 at Beltsville, MD and its Meteorological Influences

The role of ozone in the troposphere is of utmost importance as it can affect atmospheric composition and radiative properties. Its implications on human health are numerous; hence, there is a growing interest in understanding the mechanisms that lead to its formation and distribution, especially close to highly populated regions. Although many studies provide accurate estimates of these distributions, a quantitative approximation of the contribution of each process towards the total tropospheric ozone budget is not known accurately and it is still an area of ongoing research (Thompson et al., 2007, 2010; Oyola et al., 2012 (manuscript)). During July 2011, NASA conducted the DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Campaign, with the objective of improving the retrievals pertaining to air quality data retrieved by satellites near the surface, where people live and breathe. Several ground stations supported this mission around the Washington D.C. area, including the Howard University Beltsville Center for Climate System Observations (BCCSO). During this period, 36 ozonesondes were launched providing vertical profiles of ozone as well as other relevant atmospheric data. This study focused on 25 launches done in July that were chosen to prevent data overlapping. The dataset was analyzed and contrasted with synoptic and mesoscale weather analyses including NOAA-NCEP surface and upper air maps, satellite imagery, NOAA ARL HYSPLIT back trajectory analysis, and NEXRAD radar data in order to see how the ozone levels changed over time and how these concentrations may have been affected by meteorological conditions. These also show how much ozone is concentrated at the surface as well as whether or not that ozone was from stratospheric origin, originated through boundary layer dynamics, or transported by advection of air masses. Contour plots of ozone reveal important information on the origin and tropospheric depth of the clean-up events following high ozone episodes.