Variability of O3 and NO2 Profile Shapes during DISCOVER-AQ July 2011

Monday, 15 December 2014
Clare Flynn, University of Maryland, College Park, MD, United States, Kenneth E Pickering, NASA Goddard Space Flight Cent, Greenbelt, MD, United States, Lok N Lamsal, Universities Space Research Association Columbia, Columbia, MD, United States, Jay R Herman, University of Maryland JCET, Greenbelt, MD, United States, Andrew John Weinheimer, NCAR, Boulder, CO, United States, Gao Chen, NASA Langley Research Ctr, Hampton, VA, United States, Xiong Liu, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, United States, Christopher Loughner, University of Maryland College Park, College Park, MD, United States and Anne M Thompson, NASA Goddard Space Flight Center, Greenbelt, MD, United States
The first deployment of the NASA Earth Venture -1 DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) project was conducted during July 2011 in the Baltimore-Washington region. The P-3B aircraft provided in situ vertical profiles of meteorological quantities, trace gases, and aerosols over six Maryland Department of the Environment (MDE) air quality monitoring sites over fourteen flight days. Additionally, two sites launched ozonesondes and operated tethersondes during the campaign, supplementing the P-3B profiles. A major goal of DISCOVER-AQ is to understand the processes linking column abundances to surface concentrations for O3 and NO2, which includes understanding the variability of the in situ O3 and NO2 profile shapes used to compute the lower tropospheric column abundances. In support of this goal, a hierarchical cluster analysis was performed for the O3 and NO2 P-3B and sonde profiles for the Maryland 2011 campaign, allowing classes of profile shapes to be identified at each surface site. These classes were related to differences in vertical mixing, as indicated by profiles of potential temperature, CO, and short-lived trace gas species, as well as the impact of the bay breeze at one site. Such an analysis of profile variability will also be useful to assess the representativeness of the assumed profile shapes used in satellite retrievals for O3 and NO2. Further, profile shapes for these species were compared with those from the CMAQ model to assess its performance. Lastly, the average diurnal variation of the O3 and NO2 column abundances over the July 2011 campaign was assessed at each site to elucidate the diurnal cycle for these columns and results were compared to the once-per-day OMI column observations.