A41C-0075
Persistency and Intensity of Arctic Storms and their Integrated Impacts on Sea Ice Melting
Thursday, 17 December 2015
Poster Hall (Moscone South)
Wei Tao, North Carolina A & T State University, Greensboro, NC, United States, Jing Zhang, NC A&T State University, Greensboro, NC, United States and Xiangdong Zhang, University of Alaska Fairbanks, Fairbanks, AK, United States
Abstract:
The Arctic has been undergoing rapid changes. Sea ice has retreated at an accelerating rate, and storms activity has intensified. Storms transport energy to the Arctic and increase the ocean mixing of Arctic Ocean, which enhances the ice retreat. However, clouds brought by the storms can also block solar radiation, thus impede the ice retreat. This study is to investigate integrated impacts of storm on the Arctic sea ice, especially from the view of storm persistency and intensity. To investigate storm impacts on the surface radiation balance and ocean mixing, composite analysis is conducted in the years with longer- or shorter-than-usual storm durations and with higher- or lower-than-usual storm intensities. Results suggest that storms significantly cause a reduction of downwelling shortwave radiation during the melting season (April- September), leading to a cooling effect stronger than the warming effect due to enhanced longwave radiation and warm advection brought by the storms. Storm induced ocean mixing pronounced if the strong storms occur in the late melting season (July-September), when there are increased open waters in the Arctic Ocean. Considering the positive and negative impacts of the storm on the sea ice melting, a storm forcing index (SFI) is proposed, which shows a good correlation with the summer minimum sea ice extent.
