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Precipitable water and surface humidity over global oceans from special sensor microwave imager and European Center for Medium Range Weather ForecastsGlobal fields of precipitable water W from the special sensor microwave imager were compared with those from the European Center for Medium Range Weather Forecasts (ECMWF) model. They agree over most ocean areas; both data sets capture the two annual cycles examined and the interannual anomalies during an ENSO episode. They show significant differences in the dry air masses over the eastern tropical-subtropical oceans, particularly in the Southern Hemisphere. In these regions, comparisons with radiosonde data indicate that overestimation by the ECMWF model accounts for a large part of the differences. As a check on the W differences, surface-level specific humidity Q derived from W, using a statistical relation, was compared with Q from the ECMWF model. The differences in Q were found to be consistent with the differences in W, indirectly validating the Q-W relation. In both W and Q, SSMI was able to discern clearly the equatorial extension of the tongues of dry air in the eastern tropical ocean, while both ECMWF and climatological fields have reduced spatial gradients and weaker intensity.
Document ID
Document Type
Reprint (Version printed in journal)
Liu, W. T. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Tang, Wenqing (JPL Pasadena, CA, United States)
Wentz, Frank J. (Remote Sensing System Santa Rosa, CA, United States)
Date Acquired
August 15, 2013
Publication Date
February 15, 1992
Publication Information
Publication: Journal of Geophysical Research
Volume: 97
ISSN: 0148-0227
Subject Category
Distribution Limits