A Synoptic Comparison of SSM/I Winds with Output from an Operational Forecast System

Abstract

Near-surface wind speed analyses from the Special Microwave/Imager (SSM/I) are compared with those from an operational numerical forecast system. Substantial agreement exists, especially over open ocean. Nevertheless, the use of both fields together should lead to a better understanding of the synoptic situation than the use of either field alone. The SSM/I winds give a superior representation of spatial variations of wind speeds. Also, the SSM/I information can he used to examine continental influences on marine wind speeds. Such mesoscale effects are not analyzed well by global numerical models. On the other hand, the output from the numerical forecast system provides wind direction, a parameter not available from the SSM/I. In addition, forecast system winds fill in information between satellite passes and in regions contaminated by precipitation.