Evaluation of the global atmospheric moisture budget as seen from analyses

For the period 1987 to 1993, quantities central to the global moisture budget from the global analyses of the European Centre for Medium-Range Weather Forecasts (ECMWF), the US National Meteorological Center (NMC), and NASA/Goddard have been computed and compared. The precipitable water is computed and compared with satellite data from the Special Sensor Microwave Imager (SSM/I). Fluxes of moisture and their divergence have been used to estimate the vertically integrated moisture budget and thus evaporation minus precipitation (E-P) as residuals. Results of several test computations show that small biases exist in precipitable water as vertical resolution and methods of computing vertical integrals are changed, but the impact is small on the moisture budget. -from Authors