The total mass of the atmosphere

Abstract

Accurate but approximate formulae for determining the mass of the atmosphere in terms of the surface pressure p"SUB s" are derived and applied to globally analysed data from the European Centre for Medium-Range Weather Forecasts (ECMWF) for 1985 through 1993. The formulae take into account effects of the shape of the Earth and variations in gravity with latitude and height. Variations in total mass occur because of changes in the water vapor loading of the atmosphere. Independent computations are made of the surface pressure due to water vapor p"SUB w" , which is proportional to the precipitable water, using the ECMWF analyses of specific humidity. Spurious trends in both the mass of dry air and the atmospheric moisture are found to arise from changes in the analysis system at ECMWF, confounding attempts to seek real trends associated with climate change. (from Authors)