SeaSTAR is a new satellite mission concept dedicated to observing small-scale ocean surface dynamics in coastal seas, continental shelf seas and Marginal Ice Zones. The mission is currently under study as a candidate for the European Space Agency Earth Explorer 11 programme.
High-resolution satellite images of sea surface temperature and ocean colour reveal an abundance of ocean fronts, swirls, vortices and filaments at horizontal scales below 10 km that permeate the global ocean, especially near mesoscale jets and eddies, in coastal seas and close to sea ice margins. These small-scale ocean features are the fingerprints of dynamic atmosphere-ocean interactions and intense ocean vertical processes that mediate exchanges across all the fundamental interfaces of the Earth System – between the atmosphere, the ocean surface, the ocean interior, the cryosphere and land – and impact major aspects of the global climate system. Better representation of small-scale ocean processes in models is a recognised priority to improve operational forecasts and reduce uncertainties in climate projections, notably regarding the response of the marine environment and ecosystems to anthropogenic pressures and climate change.
SeaSTAR proposes to measure two-dimensional images of Total Surface Current vectors, Ocean Surface Winds vectors and directional wave spectra with unprecedented resolution, precision and sampling. For the first time, SeaSTAR offers the sensitivity, fine spatial resolution, high accuracy, wide swath and flexible temporal sampling needed to observe and quantify these fast-evolving ocean processes on daily to multi-annual scales, across different ocean conditions and latitudes, over all coastal and shelf seas and MIZs. SeaSTAR’s innovative squinted SAR interferometer makes it possible to retrieve both components of the ocean surface current vector and the wind vector simultaneously in a single pass, with fine resolution and high accuracy.