Detection of recurrent lead formation mechanisms at Point Barrow with MODIS imagery

Long openings in sea ice, called leads, are dynamic features that strengthen air-sea interactions, drive ice production, and enhance large-scale sea ice deformation. During winter and spring, systems of leads form repeatedly under the influence of winds, ocean currents, and ice-coast interactions. We investigate the mechanisms causing leads originating at Point Barrow, a prominent Alaskan headland that extends into the sea ice cover of the Chukchi and Beaufort Seas. The formation of these recurrent lead patterns drives episodic changes in sea ice concentration and drift that impact marine and human life, and are challenging to predict. We use Moderate Resolution Imaging Spectroradiometer (MODIS) thermal infrared imagery from Terra and Aqua satellites to identify recurrent lead patterns during the months of January-April of 2000-2020. Using ERA5 reanalysis to identify weather patterns that precede the formation of the recurrent lead patterns, mechanical modes of lead formation are proposed. Impacts of the mode of lead formation on regional sea ice drift are assessed using Polar Pathfinder sea ice motion. The results of this analysis contribute to improved predictive capabilities for the episodic occurrences of these large-scale features and their impacts on physical and biological processes in the Chukchi and Beaufort Sea region.