J1.16
Warm season processes at SHEBA
Kirstie L. Stramler, Columbia University, New York, NY; and A. D. Del Genio and W. B. Rossow
The central theme of work presented at the 7th AMS Conference on Polar Meteorology and Oceaonography - that during the Arctic winter over perennial sea ice, the surface and atmosphere couple into persistent, synoptically-driven preferred states, as diagnosed by the instantaneous value of the surface net longwave radiation (NetLW) - is evaluated during the canonically defined spring and summer seasons at SHEBA.
It will be demonstrated that the atmosphere over the SHEBA locale exhibits oscillatory behavior between winter and summer quasi-equilibrium states, and that the spring warming is largely achieved via the same mechanisms available to the winter constituents, as the surface and subsurface media gradually warm in synoptically-driven, dynamic, stepwise equilibria.
Insolation will be shown to initially slow the surface warming by thinning the near-surface clouds, then ultimately, at the height of the late-spring solar forcing and as the surface albedo begins to dip toward its summer minimum, to be sufficient to maintain surface temperatures under clear skies. The summer season will be shown to be a quasi-equilibrium with different processes at work, dominated instead by local, shortwave-driven, surface latent heat (LH) release as much as by synoptic influxes of temperature and moisture.
.Joint Session 1, Polar Coastal Processes (Joint with Sixth Conference on Coastal Atmospheric and Oceanic Prediction and Processes and the 8th Conf on Polar Meteorology and Oceanography)
Monday, 10 January 2005, 8:55 AM-5:45 PM
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