Aquarius Faraday Rotation Observations

Aquarius is a space-borne 3-beam L-band microwave instrument with its radiometer measuring sea surface salinity and its scatterometer providing ocean roughness corrections for better retrieval. Since polarized signals are used in both salinity and surface wind retrievals, Faraday rotation correction is an important step in calculating both radiometer and scatterometer ocean surface signals. In current ground processing algorithm, data version 3.0, scatterometer Faraday rotation is derived from predictions based on TEC inputs while radiometer Faraday rotation is computed using second and third stokes measurements. Analysis shows general agreement between these two values for all three beams. Discrepancies reside along certain geolocations and vary seasonally.