A Comparison of Arctic Ozone Depletion Event Characteristics from Coastal- and Ocean-based Observations

When the sun rises in the Arctic spring, photolytically active halogen species (Cl2, Br2, and I2, and interhalogens) are released into the lower atmosphere, causing episodic depletions of boundary layer ozone. These Arctic ozone depletion events (ODEs) have been primarily studied from coastal sites; however, a recent series of deployments of autonomous, sea-ice tethered instrumented observatories (O-Buoys) has allowed for "long"-term, in-situ examination of ODEs from the frozen Arctic Ocean surface. These Arctic Ocean measurements can help address what effects prevailing local sea ice conditions have on the timing, frequency, and duration of ozone depletion, and if there exists a particular Arctic Ocean event source region. In this study, we compare Arctic Ocean-based and coastal measurements of ozone, radiation, and meteorological parameters from March through June in 2007, 2010, 2011, 2012, and 2014, as they pertain to ODEs, as well as with sea ice conditions derived from satellite observations. A backward air mass trajectory study was also performed to trace the history of ozone-depleted air masses. We subsequently compared these trajectories with satellite bromine monoxide and sea ice observations to probe locations for bromine activation. Here we present and discuss the results of these investigations.