CoAuthors

Rosemary Morrow (LEGOS, France)

The Surface Water and Ocean Topography (SWOT) Mission has entered Phase B with planned launch in 2020. The objectives of the mission are to utilize radar interferometry technique to measure the elevation of water for tracking ocean currents and water on land. The trust of the mission in oceanography is to reduce the measurement noise by two orders of magnitude from the performance of conventional nadir-looking altimeter over a swath of 120 km wide, allowing the observation of ocean topography down to 15 km wavelength in two dimensions over most of the global oceans. To ensure the coverage of the entire earth between the 78-degree latitudes dictated by the mission's non-sun-synchronous orbit, the orbit repeat period is 22 days. The number of observations at a given location in a repeat cycle ranges from 2 near the equator to more than 10 at the highest latitudes. To reconstruct SSH from the irregularly sampled observations with complex error characteristics will pose a significant challenge for advancing the study of ocean circulation from this new type of observation. For instance, what are the prospects of estimating 3-D ocean currents from the observation based on theoretical considerations? What are the approaches to validate the observations? The presence of internal tides and small-scale coastal tides will create complications in interpreting the data. How are we going about improving these tide models? Can we characterize and correct for other geophysical effects from ocean surface waves such as the EB bias? The SWOT Science Definition Team (SDT) has formulated the mission's science requirements and defined their challenges. The SDT will be phased out at the end of 2015. A new Science Team will be established in 2016 to carry out studies addressing the challenges to meet the mission's objectives. Announcement of opportunity to submit proposals for becoming a member of the Science Team will be issued in early 2015. We anticipate the OSTST community will respond to the opportunity to develop the next generation of altimetry with enthusiasm.