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Meissner, T., Wentz, F., and Hilburn, K. (12-Nov-13)

Our presentation discusses the three major steps in the Aquarius Level 2 salinity retrievals to get from the current V2 to the proposed V3 release and their impact on instrument performance. The first is the correction for wind roughened ocean surface. The Aquarius L-band scatterometer allows an accurate measurement of the ocean surface wind speed at the instance of the Aquarius radiometer observation. The second is the correction for reflected galactic radiation. Its size varies with season and latitude of the observation. If left uncorrected the error in salinity would exceed 8 psu. The V2 algorithm uses a physical geometric optics model for the reflection of the galactic radiation from the ocean surface. This removes the unwanted galactic signal to about 90%. The remaining 10% error shows up in the data as bias between the salinity values from the ascending and descending swaths. In order to remove this spurious bias we have derived an empirical correction that is applied in addition to the geometric optics correction. The third is an adjustment of the spillover value in the antenna pattern correction, which improves the large biases that we have been seeing over land and ice scenes in V2.