Vertical Variability Of Aerosol Properties And Trace Gases Over A Remote Marine Region: A Case Study Over Bermuda
Presenter: Taiwo Ajayi P21
Co-Author(s): Yonghoon Choi, Ewan C. Crosbie, Joshua P. DiGangi, Glenn S. Diskin, Marta A. Fenn, Richard A. Ferrare, Johnathan W. Hair, Miguel Ricardo A. Hilario, Chris A. Hostetler, Simon Kirschler, Richard H. Moore, Taylor J. Shingler, Michael A. Shook, Cassidy Soloff1, Kenneth L. Thornhill, Christiane Voigt, Edward L. Winstead, Luke D. Ziemba, Armin Sorooshian
Advisor(s): Armin Sorooshian
1Hydrology & Atmospheric Sciences
Remote marine regions comprise a high fraction of Earth’s surface, but measurements over these locations remain scarce. Here we use airborne data during 15 vertical spiral soundings over Bermuda during the NASA Aerosol Cloud meTeorology Interactions over the western ATlantic Experiment (ACTIVATE) to understand the vertical structure of trace gases, aerosol particles, and meteorological variables over 1000 km offshore of the U.S. East Coast. Results reveal (i) significant differences in vertical profiles of variables between three different air mass source categories (North America, Ocean, Caribbean/North Africa) such as with the strongest (weakest) pollution signature from North America (Ocean) categories and a pronounced coarse aerosol signature in the free troposphere (FT) and reduced aerosol hygroscopicity in air masses from the Caribbean/North Africa; (ii) North American air generally has the highest levels of CO, CH4, submicron particle number concentration, AMS mass, and highest organic mass fraction; (iii) Ocean air masses have the highest relative amount of nitrate, non-sea-salt sulfate, and oxalate, which are key acidic species participating in chloride depletion; (iv) considerable vertical heterogeneity for almost all variables with altitude, including higher O3 and submicrometer particle concentrations with altitude, suggestive that the FT is a potential contributor of both constituents in the marine boundary layer; and (v) bimodal particle size distributions for each air mass type suggestive of cloud processing effects (i.e., Hoppel minimum). This study demonstrates the sensitivity of the remote marine vertical structure to different air mass sources and the significant vertical variability in atmospheric trace gases and aerosol constituents.