The operational determination of wind stress on the Arctic ice pack

Abstract

The performance of routine FNWC sea level pressure analyses and forecasts in the Beaufort Sea is evaluated for driving an ice model. The geostrophic winds determined from the FNWC pressure fields are compared to geostrophic winds determined from the AIDJEX experiment observations. A simulation with the AIDJEX model has been run using FNWC sea level pressure analysis fields for the period 15 to 25 May 1975 and compared to the AIDJEX results. RMS sea level pressure errors of about 3 mb were found with analysis errors reduced by about 1 mb when one AIDJEX observation was included in the analysis. Geostrophic winds had speed differences of about 40% and direction differences of about 50 deg. The FNWC simulation with the AIDJEX model produced a position error of about 7 km for one station over the ten day run. Recommendations are made to improve the FNWC hemispheric fields in the Arctic for application to ice forecasting.