HR: 16:32h
AN: OS34A-03    [Abstracts]
TI: Determination of Atmospheric Properties Over Arctic Polynyas
AU: * Key, E L
EM: ekey@rsmas.miami.edu
AF: University of Miami, RSMAS, 4600 Rickenbacker Causeway, Meteorology and Physical Oceanography Division, Miami, FL 33149 United States
AU: Minnett, P J
EM: pminnett@rsmas.miami.edu
AF: University of Miami, RSMAS, 4600 Rickenbacker Causeway, Meteorology and Physical Oceanography Division, Miami, FL 33149 United States
AB: Due to the relatively sparse in situ and satellite-derived data collection at polar latitudes, model analyses rely primarily on coastal weather station time series for atmospheric initialization. Values from these sites are extrapolated over adjacent marine environments, including nearby polynyas - areas of open water within the ice pack. However, most weather stations are topographically-shadowed or under the influence of katabatic drainage, so that measurements are localized and unrepresentative of the area covered by large-scale analytical grids. Moreover, the surface fluxes over land are not comparable to those in a polynya environment, where there are increases heat and moisture exchange across the oceanic interface, often leading to the formation of convective cloud at the downwind polynya edge. To determine the best accuracy of analyzed moisture and temperature profiles, independent, ship-based radiosondes collected offshore of the flat, ponded, coastal plain at Barrow, Alaska are compared against upper air observations from a weather station, the ARM (Atmospheric Radiation Measurement) North Slope of Alaska-Adjacent Arctic Ocean site, MODIS retrievals, and the NCEP Final Analysis (FNL) 1-degree moisture and temperature profiles. While the atmospheric temperature structure agrees well amongst the five data sets, the analyzed and retrieved humidity profiles do not capture the boundary layer moisture, and are in fact drier than upper air observations despite a known "dry bias" in radiosonde data. Comparisons of surface fields are limited to ship-model match-ups and largely reflect limitations of coarse model resolution.
DE: 3337 Numerical modeling and data assimilation
DE: 3349 Polar meteorology
DE: 3360 Remote sensing
DE: 4540 Ice mechanics and air/sea/ice exchange processes
DE: 0350 Pressure, density, and temperature
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting