Evaluation of WRF model resolution on simulated mesoscale winds and surface fluxes near Greenland

The seas around Greenland are climatically important because they are one of the few areas where deep ocean convection has been observed. This region also has short-lived, but frequently occurring mesoscale barrier winds and tip jets that form when synoptic scale atmospheric features interact with the topography of Greenland. Both these types of wind features have high surface wind speeds, and barrier winds flow over the ocean parallel to the coastline while tip jet events extend either eastward or southwestward from Cape Farewell over the ocean. The influence of these mesoscale atmospheric features on the ocean, particularly deep convection, is not yet well understood. Because obtaining observations is difficult in this region, model simulations are essential for understanding the interaction between the atmosphere and ocean during mesoscale wind events. In spring 2007 the Greenland Flow Distortion Experiment (GFDex) took the first in-situ observations of an easterly tip jet as well as observations of barrier flows. These data provide a detailed picture of the vertical structure of the winds and provide measurements of turbulent heat fluxes between the atmosphere and ocean during the high wind speed events. This research presents output from the Weather Research and Forecasting (WRF) model driven with the ECMWF ERA-Interim reanalysis product at four resolutions (100km, 50km, 25km, 10km). Case study comparisons between WRF output at different resolutions and the GFDex observations as well as QuikSCAT satellite data highlight the importance of high resolution for properly capturing wind events and surface fluxes of latent and sensible heat. In addition, the impact of mesoscale winds on the ocean is investigated by comparison of surface fluxes and winds between model resolutions over a two-month period.