Sea surface salinity and wind retrieval algorithm using combined passive-active L-band microwave data.

Abstract

Aquarius is a combined passive/active L-band microwave instrument developed to map the salinity fireld at the surface of the ocean from space. The data will support studies of the coupling between ocean circulation, the global water cycle, and climate. The primary science objective of this mission is to monitor the seasonal and interannual variation of the large scale features of the surface salinity field in the open ocean with a spatial resolution of 150 km and a retrieval accuracy of 0.2 psu globally on a monthly basis [1]. The measurement principle is based on the response of the L-band (1.413 GHz) sea surface brightness temperatures (Tᴃ) to sea surface salinity. To achieve the required 0.2 psu accuracy, the impact of sea surface roughness (e.g. wind-generated ripples and waves) along with several factors on the observed brightness temperature has to be corrected to better than a few tenths of a degree Kelvin. To the end, Aquarius includes a scatterometer to help correct for this surface roughness effect [2,3].