Mitigating the impact of RADCAL beacon contamination on F15SSM/I ocean retrievals

Data from six Special Sensor Microwave/Imagers (SSM/I) have been used to provide a 22-year climate data record of surface wind speed, columnar water vapor, columnar cloud water, and surface rain rate. On 14 August 2006, a radar calibration (RADCAL) beacon was activated on F15, one of the SSM/I. Interference from the beacon caused retrieval biases of roughly -30% for wind and rain and 40% for vapor and cloud. We have developed a simple correction for RADCAL interference, which brings the retrieval biases down to a few percent for cloud and rain, and less than 1% for wind and vapor. The corrected F15 data are of suitable quality for weather research purposes, but we discourage use of F15 retrievals after 14 August 2006 for climate research purposes at present because it appears that RADCAL beacon interference may not be stable in time, but may depend upon the thermal environment of F15.