4.3 The climatological distribution of extreme Arctic winds, and implications for ocean and sea ice processes

Monday, 29 April 2013: 4:15 PM
South Room (Renaissance Seattle Hotel)
Mimi Hughes, CIRES, Boulder, CO; and J. J. Cassano

Some of the strongest near-surface winds on Earth form in the Arctic due to mesoscale processes such as polar lows and barrier jets. The strong surface winds in the arctic have important impacts on ocean and sea ice circulation. We examine the climatological distribution of near-surface wind speeds within a pan-Arctic domain in three gridded datasets: the ECMWF Interim analysis (ERA-I) and two regional climate simulations generated using the Weather, Research, and Forecast model run at 50 km (WRF50) and 10 km (WRF10) horizontal resolutions with ERA Interim as lateral boundary conditions. To examine the influence of spatial resolution on near surface wind speeds, we estimate probability density functions of each dataset's wind speed at 10m and the lowest model level for a single year (where all three datasets are available), as well as for an 18-year (1990-2007) average (ERA-I and WRF50 only). We also show the annual cycle and long-term maps of the 90th, 95th, and 99th percentiles and maximum wind speeds. We perform the same analysis on sea level pressure maps and gradients in the WRF50 simulation to briefly explore the atmospheric dynamics associated with these strong surface winds. Finally, to tie these results to their implications for ocean and sea ice processes, we perform a similar analysis on surface fluxes and wind stress. The results from these atmospheric-only simulations will be useful for estimating the sensitivity of coupled models to atmospheric resolution.
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