The Impact of an Intense Cyclone on Short-Term Sea Ice Loss in a Fully Coupled Atmosphere-Ocean-Ice Model

Arctic cyclones may be associated with periods of locally enhanced sea ice loss during the summer, and some studies have found that an intense cyclone in August 2012 resulted in a rapid sea ice retreat. This study uses a coupled atmosphere-ocean-ice model (Navy-ESPC) to explore the relationship between the 2012 cyclone and short-term sea ice melting. There are two mechanisms of cyclone-induced melting in Navy-ESPC: turbulent mixing of a warm layer located at 15- to 35-m depth increases bottom melting and warm air advection by the strong surface winds increases surface melting. Although the rate of sea ice melt is substantially increased in association with the cyclone, this effect is confined to a relatively small region and only lasts for a few days. There is no clear signature of the cyclone on the overall Arctic sea ice extent in Navy-ESPC. Plain Language Summary Cyclones (storms) over the Arctic Ocean may be associated with periods of locally enhanced sea ice loss during the summer, and some studies have found that an intense cyclone in August 2012 resulted in a rapid sea ice retreat. This study uses a computer model (Navy-ESPC) that includes interactions between the atmosphere, the ocean, and the sea ice, to explore the relationship between the 2012 cyclone and short-term sea ice melting. In this model, there are two mechanisms by which melting of sea ice is enhanced by the cyclone: (1) warm water from below is mixed upward, which increases the rate of melting on the bottom of the sea ice, and (2) warm air is brought northward by the strong winds of the cyclone, which increases the rate of melting on the top of the sea ice. These two mechanisms combine to substantially increase the rate of melting of sea ice, but the effect of the cyclone on the sea ice is confined to a relatively small region and only lasts for a few days. In this model, there is no clear effect of the cyclone on the overall extent of the sea ice over the Arctic Ocean.