Arctic Surface and Atmospheric States: NSA Analogs to SHEBA and Interannual Variability

Both winter and summer at the Surface Heat Budget of the Arctic Ocean (SHEBA) site can be described as dynamic equilibria between surface and atmosphere, where, for each season, different mechanisms are used by the constituent media to exchange energy. The wealth of measurements at SHEBA that allowed the processes of energy exchange there to be examined in such detail are only available for a single calendar year. However, a multiple year, high temporal resolution observational record is available nearby, from the Atmospheric Radiation Measurement (ARM) Program's North Slope of Alaska (NSA) Point Barrow installation. Here we consider how representative the Point Barrow site is of the SHEBA site, for both warm and cold season processes, by highlighting common traits of the atmosphere as it interacts with two prevalent Arctic surface types (perennial sea ice at SHEBA and tundra-topped permafrost at NSA). We also investigate the interannual variability of clear and cloudy sky surface air temperature, surface radiation fluxes, and atmospheric temperature and humidity structure at NSA, finding similar preferred modes of behavior there as observed at SHEBA, with clear sky temperature and moisture variations accounting for the bulk of the interannual variability in surface radiative energy exchange.