5:15 PM - 6:30 PM
[ACG39-P04] Impact of sea-ice cover on storm-mediated atmospheric warming over the Barents Sea: A regional modelling study
Keywords:cyclone, Arctic amplification, heat transport
Sea-ice loss is believed to be one of the key processes in the recent Arctic warming. This study examines the impact of sea-ice cover on the atmospheric warming associated with cyclones. Although cyclones are an important component in the Arctic climate system, details regarding the process of heat transfer during life cycles of cyclones remain unclear. The cyclone that occurred over the Barents Sea in January 21–25, 2011 was selected as the test case given that it was well validated using in-situ data. The results of numerical simulations showed that the changes in surface heat fluxes and net long-wave radiation owing to sea-ice cover changes resulted in atmospheric warming via vertical diffusion, countered by cold advection within the atmospheric boundary layer, which corroborates earlier studies. The simulations also showed that sea ice decline intensified the advection of warm air over areas north of the sea-ice edge resulting from the southerlies associated with the cyclone and caused further atmospheric warming east of Svalbard. It was also observed that a large fraction of warmed air parcels traveled well above the top of the boundary layer. This enhanced “on-ice” flow regime and upglide of the warmed air parcels associated with cyclones could play a role in spreading out the effect of anomalous heat supply due to the sea-ice decline and contribute to further atmospheric warming in the Arctic during winter.