ATMOSPHERIC NET TRANSPORT OF WATER-VAPOR AND LATENT-HEAT ACROSS 60-DEGREES-S

The mean annual moisture flux across 60 degrees S is estimated using r esults of numerical analyses produced by the U. S. National Centers fo r Environmental Prediction and the European Centre for Medium-Range We ather Forecasts for the 7-year period 1985-1991. The atmospheric data indicate a net poleward transport of 17.06 kg m(-1) s(-1) or 10.74 Tt yr(-1). The mean annual moisture transport divergence for the area pol eward of 60 degrees S is estimated using a combination of surface and near-surface data (precipitation and evaporation for the Southern Ocea n, net surface accumulation and seaward drifting snow transport for th e Antarctic ice sheet). The mass exchange rates at the ice sheet-atmos phere and ocean-atmosphere interfaces are integrated strictly for the area between 60 degrees S and 70 degrees S and are combined with the r esults of a preceding surface data estimate of transport divergence fo r the area poleward of 70 degrees S. The surface data are a combinatio n of diverse sets representative of various multiyear periods distribu ted through 1941-1990 and indicate a poleward transport of 18.60 kg m( -1) s(-1) or 11.79 Tt yr(-1) across 60 degrees S. The estimates based on atmospheric and surface data show remarkable agreement (the differe nce is well within the error estimates) and indicate net atmospheric t ransports of water vapor and latent heat poleward across 60 degrees S of 17.8 kg m(-1) s(-1) and 50 MJ m(-1) s(-1), respectively.