Atmospheric moisture transport across the Southern Ocean via satellite observations

Meridional moisture transport across the Southern Ocean was measured using a combination of TIROS operational vertical sounder and special sensor microwave/imager satellite data from 1988. Satellite and radiosonde estimates of moisture flux compare favorably near Macquarie Island (54.5 degrees S, 158.9 degrees E). The zonally averaged, vertically integrated, moisture flux values across 50 degrees S and 60 degrees S are -31.8 and -15.2 kg m(-1) s(-1) respectively. Resulting moisture convergence for the 50 degrees-60 degrees S latitude band is 636 +/- 50 kg m(-2) yr(-1), about 50% larger than indicated by contemporary studies using radiosondes or atmospheric analyses. Within this latitude band the poleward moisture transport peaks in the South Pacific sector near 135 degrees E, with a secondary maximum in the Amundsen Sea sector close to 135 degrees W. There is a dramatic moisture flux discontinuity across the Antarctic peninsula and the tip of South America near 45 degrees W, with equatorward moisture transport at all latitudes in the Weddell Sea sector. A regional study of West Antarctica indicates large poleward moisture pur is accomplished through the Belingshausen and Amundsen Seas only.