Observations of Terrestrial Biogenic and Biomass Burning Aerosol Impacts on Marine Stratocumulus off the Coast of California
Monday, 15 December 2014: 4:00 PM
The nature of anthropogenic and marine aerosol interactions with stratocumulus clouds off the coast of California has been widely examined, yet limited studies have evaluated aerosol-cloud interactions resulting from terrestrial biogenic and biomass burning emissions. This study presents aircraft data from the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) and 2013 Nucleation in California Experiment (NiCE). We investigate mechanisms by which biogenic and biomass burning aerosols originating from the Northwest United States are transported to the marine atmosphere. We present data showing the spatial extent to which these particles impact the free troposphere above marine stratocumulus and highlight their influence on cloud water composition and cloud condensation nuclei (CCN). Terrestrial biogenic and biomass burning particles had the greatest impact on marine aerosol and clouds north of San Francisco, CA due to synoptic-scale meteorology. These aerosols were observed to be CCN-active and led to elevated cloud water concentrations of species such as nitrate, acetate, formate, and oxalate.