Initial user impact studies of the next generation ocean surface vector wind scatterometer mission (XOVWM)

Satellite ocean surface vector wind (OSVW) data from the NASA QuikSCAT research mission have become an extremely valuable tool in NOAA's operational marine and tropical cyclone weather forecasting and warning operations. The next challenge is for the global satellite OSVW measurement capability of the United States to make the transition from a research capability to a sustained operational capability. NOAA is currently working with NASA's Jet Propulsion Laboratory (JPL) to study two OSVW mission options: (i) a QuikSCAT-equivalent capability and (ii) a more advanced satellite OSVW capability (XOVWM). The impacts that QuikSCAT wind measurements have had on NWS forecasts and warnings were reviewed at NOAA's Operational Ocean Surface Winds Workshop held in June 2006. What will be presented here are the results of a study to estimate the impact that OSVW measurements obtained from a next-generation scatterometer (XOVWM), rather than a QuikSCAT-equivalent scatterometer, could have on NOAA's operational weather forecasting and warnings. One focus of this study is on the anticipated performance, using simulated observations, of a next-generation scatterometer in hurricanes, where QuikSCAT has exhibited significant limitations.

To achieve the study goals we investigated the differences in performance between the two OSVW mission options in tropical cyclones, extratropical cyclones, and coastal wind jet events using simulated wind retrievals based on the design of both the QuikSCAT-equivalent instrument and XOVWM.

The first set of studies as it applies to cyclones at sea assessed the extent that the increased resolution and decreased sensitivity to rain of with XOVWM, as compared to a QuikSCAT-equivalent capability, will result in:

– More reliable estimates of tropical cyclone intensity through all stages of development, from tropical depression to major hurricane

– Improved analysis of tropical cyclone wind field structure (34, 50, and 64 kt radii), which could contribute to more refined coastal watch/warning areas

– More accurate tracking of tropical cyclone centers and earlier identification of developing systems, contributing to more accurate initial motion estimates and numerical model initialization

– More accurate maximum wind estimates of extratropical cyclones and detection of all warning categories

A second set of studies addressed the extent to which one can achieve better definition of coastal wind features including orographically-induced or enhanced low-level jets with XOVWM. The results and implications of both studies will be presented and discussed.