. Arctic Cyclones and Their Impacts on Sea Ice

Abstract
Arctic cyclones have received notoriety in the past decade for their perceived recent greater intensity and their increased impacts on the sea ice and its annual advance/retreat cycle. From extensive mid-latitude studies of cyclones, it is known that the intensity, key developmental processes, and surface interactions tend to be concentrated near mesoscale features of the cyclones. However, similar mesoscale observations of Arctic cyclones have been rare because of the difficulty in deploying the necessary instrumentation over the Arctic Ocean within these intermittent events. Such instruments include surface-based radars and other remote sensors, in-situ surface observations, extensive atmospheric soundings, and airborne kinematic, thermodynamic, and microphysical measurements. This presentation will provide observational examples of the mesoscale atmospheric structure of cyclones over the Arctic Ocean as obtained from the few deployments of such instruments during field programs over the past 30 years from SHEBA (1997-1998), ASCOS/AMISA (2008), and ACSE (2014). Examples will include cyclones near the North Pole in mid-August 2008 and in the Beaufort/Chukchi Seas in mid-winter 1998, late summer 1998, and early September 2014. The presentation will emphasize atmospheric mesocale features and processes important for air-ice(snow) or air-ocean interactions, such as strong surface winds (strong momentum flux), mesoscale deformation, and strong surface heat fluxes. These Arctic cyclone features impact ice motion (inertial oscillations), lead formation, ice melt, ice growth, ice convergence/divergence, and upper ocean heat loss.