Background
Observations of ocean surface winds are vital for marine navigation, predicting hurricanes and other oceanic storms, and science and modeling of the ocean-atmosphere interface. The Satellite Needs Working Group (SNWG)-2022 assessment found that providing gridded, harmonized winds near the ocean surface would help support the needs of several agencies.
The Multi-Sensor Worldwide Ocean Winds (M-WOW) product will enable a new harmonized wind retrieval product suite combining wind retrievals from a variety of different satellite-based wind-observing instruments: scatterometers (Advanced Scattermotemter (ASCAT)-B/C, Scatterometer for Oceansat-3 (OCSAT-3)), Synthetic Aperture Radar (SAR) instruments (Sentinel-1, RADARSAT-2, NASA-Indian Space Research Organisation (ISRO) Synthetic Aperture Radar (NISAR), Advanced Land Observing Satellite-4 (ALOS-4), Surface Water and Ocean Topography (SWOT), commercial SARs), and passive microwave radiometers (Compact Ocean Wind Vector Radiometer (COWVR), Global Precipitation Measurement (GPM) Microwave Imagery (GMI), Soil Moisture Active Passive (SMAP), Special Sensor Microwave Imager/Sounders (SSMISs), Advanced Microwave Scanning Radiometer (AMSR)-2/3) to generate gridded wind speed data every ~6 hours.
Wind direction will be provided from available sensors (i.e. from scatterometers and polarimetric radiometers). This combined product will greatly increase the temporal resolution and spatial coverage of ocean surface wind as compared to the existing, instrument-specific data, and will provide harmonized analysis-ready data from a single source, with a common format and grid. The development of wind stress and the spatial derivatives of the wind and the stress (curl and divergence, when wind direction is available) are being evaluated for a potential added-on element of the primary product suite. The new product will have two important characteristics:
- A better characterization of the uncertainty from the stand-alone, instrument-specific wind retrievals
- A unified set of wind speed estimates that harmonize the retrievals from the different instruments, providing an instrument-agnostic estimate of the wind-speed
A comprehensive, observations-only, product such as M-WOW does not yet exist.