Scientific Opportunities Provided by SeaWinds in Tandem

The intense observations of ocean surface vector winds by spacebased scatterometers in the past decade have confirmed the rich spatial and temporal scales in ocean surface wind fields, and have improved our understanding of their complicated interactions. Studies based on these data underscore that the objectives of the National Aeronautics and Space Administration (NASA) in monitoring, understanding, and predicting environmental and climate changes can be better served by observations at higher resolutions than those provided by a single scatterometer in polar orbit. Tandem Quick Scatterometer (QuikSCAT) and Advanced Earth Observing System (ADEOS)-II, with SeaWinds scatterometers on both spacecraft, offer unique opportunities to address key science objectives of the Earth Science Enterprise (ESE) at NASA. The tandem mission provides for 60% of global coverage in 6 hours and 90% in 12 hours, in a sampling pattern that is similar from one region to the next in terms of swath and swath-gap distributions. Global ocean surface vector wind information at this frequency is essential for resolving diurnal and local inertial period variability that drive ocean mixing and transport processes, which in turn integrate to affect Earth system variability on seasonal and longer timescales. The high-frequency winds have significant impact on simulation of long-term ocean state and variability. They will help us to understand the influence of super cloud clusters embedded in Madden-Julian Oscillation on El Niño / Southern Oscillation. They will resolve daily variation of land-sea breeze that changes coastal ecology, and will monitor coupled biological-physical processes affecting air-sea gas exchanges. They will improve global numerical weather forecasts, as well as regional forecasts, such as the low-level jets in South America that bring moisture from the the Amazon to the economically vital La Plata region. The tandem mission offers significant benefits in operational applications, including tropical cyclone warning systems. Sub-daily resolution in microwave returns from the tandem mission is also critical to studies of forest ecosystem and tree ecophysiology. They reduce the time needed to map polar iceedge and to track iceberg. They provide more accurate assessment of polar ice-melt, which is critical to understand changes in global ice-balance.