Optimizing the United Kingdom meteorological office data assimilation for ERS-1 scatterometer winds

At the UKMO the assimilation of a ind observations derived from ERS-1 scatterometer measurements has shown a beneficial impact in the Southern Hemisphere. Monitoring of this data shows it to be both of high quality and to have good coverage particularly in the data-spare regions of the southern oceans. The changes made to the operational analysis correction assimilation scheme allow the best use of the ERS-1 wind data are discussed. Impact studies demonstrating both the effectiveness of these changes and the beneficial impact of the ERS-1 scatterometer wind data are presented. As a result of these studies the scatterometer data and the WINDBAL assimilation balance code were included in the global operational data assimilation on 4 August 1993.