A comparison and validation of algorithms for retrieving water vapor content from SSM/I over ocean

摘要

A matchup dataset that contains the SSM/I measurements from F14 satellite and the columnar water vapor (CWV) radiosoundings taken in or near the China Sea was established to cover the period from April 1998 to June 1999. CWVs retrieved from two statistical and two semistatistical retrieval algorithms were compared to radiosonde CWVs using the matchup dataset. It is indicated that the root-mean-square (RMS) error of these retrievals relative to the radiosonde data ranges from 4.483 kg m~(-2) to 10.180 kg m~(-2). Three improved algorithms were developed and validated using the matchup dataset. It is demonstrated that these improved algorithms can be applied to the China Sea for retrieving CWV from the SSM/I with better accuracies relative to the four typical existing algorithms.