Evaluation of Various Surface Wind Products with OceanSITES Buoy Measurements

Abstract

o facilitate evaluation and monitoring of numerical weather prediction model forecasts and satellite-based products against high-quality in situ observations, a data repository for collocated model forecasts, a satellite product, and in situ observations has been created under the support of various World Climate Research Program (WCRP) working groups. Daily measurements from 11 OceanSITES buoys are used as the reference dataset to evaluate five ocean surface wind products (three short-range forecasts, one reanalysis, and one satellite based) over a 1-yr intensive analysis period, using the WCRP community weather prediction model evaluation metrics. All five wind products correlate well with the buoy winds with correlations above 0.76 for all 11 buoy stations except the meridional wind at four stations, where the satellite and model performances are weakest in estimating the meridional wind (or wind direction). The reanalysis has higher cross-correlation coefficients (above 0.83) and smaller root-mean-square (RMS) errors than others. The satellite wind shows larger variability than that observed by buoys; contrarily, the models underestimate the variability. For the zonal and meridional winds, although the magnitude of biases averaged over all the stations are mostly <0.12 m s?1 for each product, the magnitude of biases at individual stations can be >1.2 m s?1, confirming the need for regional/site analysis when characterizing any wind product. On wind direction, systematic negative (positive) biases are found in the central (east central) Pacific Ocean. Wind speed and direction errors could induce erroneous ocean currents and states from ocean models driven by these products. The deficiencies revealed here are useful for product and model improvement.