The storms that enter the Chukchi Sea and western Beaufort Sea region originate predominantly from the Pacific Ocean, possibly as far south as the sub-tropical Pacific region, or from the East Siberian Sea region. These storms take two primary pathways into the Chukchi and western Beaufort Seas: south to north from the Pacific Ocean (S2NP storms) and west to east from the East Siberian Sea (W2E storms). These storm types have distinct characteristics and can produce substantial local and regional changes in surface atmospheric and oceanic properties. In this study, the climatology of these two types of storms was analyzed using the Chukchi-Beaufort High-Resolution Atmospheric Reanalysis (CBHAR) dataset. The results show that the W2E and S2NP storms have the most prominent influences on surface climate and ocean properties in August and October, respectively, and that the S2NP storms are generally stronger than the W2E storms. The composite analysis of 2 m temperature fields, based on the number of S2NP storms, indicates a strong thermal contrast along the coast and suggests the occurrence of a baroclinic zone that supports storm development. The composite analysis of surface winds demonstrates that W2E storms change prevailing weak northeasterly winds to strong southerly winds over the Bering and Chukchi Seas and southerly surface winds occur on the northern coast of Alaska when the S2NP storms enter the study domain. The S2NP storms bring warm and moist air from the Pacific Ocean into the Arctic. In climatology, downward longwave and shortwave radiation at the surface are larger than surface turbulent heat fluxes. There are large differences in surface climate variables between the climatological mean and the composite analysis based on the number of storms. The composite analysis also indicates that both surface latent and sensible heat fluxes decrease when storms occur in the study area. It is suggested that storms can reduce sea ice concentration substantially in the ice areas through a combination of thermodynamic and dynamic factors. Sea ice retreat (northward) and sea ice advancement (southward) occur with southerly and northerly winds induced by the storms entering the study domain. Possible linkages were suggested between sea ice anomalies and frequency of the S2NP storms over the region.

USD: $25,000

2016-06-01 → 2018-01-01