Wednesday, 17 January 2007: 11:30 AM
Evidence of forcing of Arctic regional climates by mesoscale processes
206B (Henry B. Gonzalez Convention Center)
Many of the long-term atmospheric observatories established for the multiagency, international Study of Environmental Arctic Change (SEARCH) are located in coastal regions or in regions of complex topography, or both. Such regions are known to produce mesoclimates which may vary greatly over relatively short distances and may respond differently to changes in large-scale forcing. This may explain why climate trends vary greatly on regional scales. The processes forcing the climatic regimes and the annual surface energy budget cycle are examined at two SEARCH terrestrial sites (Alert, Nunavut; Barrow, Alaska) and one pack ice site (SHEBA). Mesoscale processes important for the annual climate at the terrestrial sites include terrain-induced flows and sea-breeze effects, emphasizing specific surface energy fluxes directly associated with these phenomena. The pack ice site shows surface energy budget characteristics that are less focused to a given wind regime. Impacts of the mesoscale regimes on the annual climate and surface energy budget cycle for all three sites will be compared and contrasted. These results suggest that the future climate change at the terrestrial sites will depend on the response of the dominant mesoscale processes to the large-scale Arctic changes, and may therefore not be of the same magnitude, nor sign, as the large-scale changes.