Large-Scale Atmospheric Moisture Cycling As Evaluated from NMC Global Analysis and Forecast Products

Abstract

Abstract The broadscale aspects of the annual cycle of monthly mean global water vapor flux, flux divergence, evaporation, and precipitation derived from the National Meteorological Center (NMC) global analysis and forecast products were examined with two objectives in mind: 1) a critical evaluation of the usefulness of recent NMC products for descriptive and diagnostic studies of the global hydrological cycle and in the process and 2) to provide additional information on the behavior of the annual cycle of selected hydrological parameters over the globe in general and over the United States in particular. The 2-year period August 1991–July 1993, was chosen for study. The global-scale characteristics of the NMC vertically integrated vapor flux fields are described in terms of the rotational and divergent components of the stationary and transient parts of the vapor flux field. Values of the zonally averaged meridional vapor flux derived from the NMC analyses are broadly similar to those presented by Peixo...