The source of sea salt aerosols in the polar regions appears to be linked to sea ice surfaces, but exact details are unclear. Defining the sources is important given the critical roles that aerosol plays in the atmosphere. For example, they affect the transmission of sunlight to the underlying surface, they affect the formation of clouds, and they host and enhance important chemical reactions. When they are deposited on ice they leave a record of past conditions that can be accessed by drilling ice cores, and that holds the potential to enable reconstruction of sea ice extent in the past. It is therefore important to understand the sources of polar sea salt aerosol and to be able to predict how they may vary with, and feedback to, climate.
It was recently proposed that the main source of this polar sea salt aerosol was the sublimation of salty blowing snow. BLOWSEA was thus designed to carry out field measurements to characterise the production of sea-salt aerosol from the evaporation of blowing snow over sea ice.
Measurements were made from the German icebreaker Polarstern, during a wintertime cruise in the Weddell Sea (June – August 2013). Using our new data, we will derive soundly-based parameterisations of sea-salt aerosol production, and use them in numerical models to test how important this source is for the polar regions.
BLOWSEA is led by Eric Wolff (University of Cambridge) in collaboration with Anna Jones, Markus Frey and Xin Yang (BAS), Phil Anderson (SAMS), and John Pyle (University of Cambridge).