Role of breakage, melt and floe size distribution on sea ice summer transition

Marginal ice zones are composed of individual sea ice floes, whose breakage and melt shape summer behavior of the pack. These processes are generally not resolved by global or regional models, due to the continuum approximations used for sea ice. Here, we leverage a Discrete Element Model to investigate the summer transition of floes within Baffin Bay during June-July 2018. The model is initialized with imagery-based shapes and evolved using characteristic forcings from the region and a range of model parameters. For the parameter regime that best fits observations, breakage and melt both impact mass loss of resolved floes (>2 km). The mass loss and floe size distribution are most sensitive to the breakage rate, compared to solar and oceanic melt parameters. The number decay of the largest floes (>13 km) is controlled by breakage, while decay of smaller floes (2 - 13 km) depends strongly on lateral melt.