A method is described to compute atmospheric mass time series from a data base of sea-level pressure analyses. The short-term hemispheric mass exchange is used to examine the validity of this method.

A 1/6 degree by 1/6 degree, latitude and longitude, terrain data base, provided by the Fleet Numerical Oceanography Center (FNOC), is used to reduce sea-level pressure to surface pressure. Surface pressure is converted to mass and summed. The FNOC sea-level pressure and the European Center for Medium Range Weather Forecasting (ECMWF) 1000-mb analyses are used to compute the mass and generate time series for the Northern Hemisphere 1946--1987 and the Southern Hemisphere 1981--1987.

The Northern Hemisphere and Southern Hemisphere mass time series are combined to show that exchanges of atmospheric mass occur between hemispheres on the order of several millibars (equivalent mass) on a time scale of days to weeks. The larger exchanges typically occur during the Northern Hemisphere winter. ¿ American Geophysical Union 1988