Contrasts in Seasonal Sea Ice Melt Processes in the Beaufort/Chukchi and Antarctic Marginal Ice Zones Observed by Autonomous Buoys

With increasing open water and fetch in the Beaufort/Chukchi Seas, processes governing the seasonal ice advance and retreat are expected to change, with the development of a new marginal ice zone (MIZ). The role of waves, storms, and coupling between increased dynamics and thermodynamic melt are all expected to increase. In the highly dynamic Antarctic MIZ, such processes likely play a strong role in driving seasonal sea ice retreat. Yet there have been few direct, continuous measurements of sea ice decay in the MIZ in either polar region. Here we present observations from two suites of autonomous ice mass balance buoys (IMBs): (1) A suite of four buoy arrays deployed in the Beaufort Sea in March, 2014, with an additional array deployed in August in the Chukchi Sea to monitor the evolution of ice conditions during the spring sea ice retreat. Each array included four or five co-sited IMBs and wave buoys equipped with digital cameras, and one automatic weather station at the array center. Combined with satellite imagery, these buoys provided a complete history of the seasonal sea ice melt. (2) A series of individual IMBs deployed between 2009 and 2013 in the Weddell, Bellingshausen, and Amundsen Seas and the East Antarctic sector which recorded both surface and basal melt processes as the buoys drifted from the interior pack to the ice edge in spring/summer. From these continuous time series of seasonal sea ice decay, coupled with satellite observations, we provide an overview of the key differences between both the surface melt processes in the Beaufort/Chukchi and Antarctic MIZs, and key differences in how sea ice dynamics is coupled to the thermodynamic melt and subsequent ice retreat of the ice edge. These differences, and similarities, highlight in what ways the Beaufort/Chukchi MIZ may become Antarctic-like, and in what ways it may not.