GDAS’s GCIP Energy Budgets

Abstract

The National Centers for Environmental Prediction?s operational global data assimilation system?s (GDAS) atmospheric and surface thermodynamic energy cycles are presented for the Mississippi River basin where the Global Energy and Water Cycle Experiment Continental-Scale International Project (GCIP) is under way. At the surface, during the winter, incoming solar radiation is balanced by longwave cooling. During the summer, latent and sensible cooling are equally important. In the atmosphere, thermodynamic energy convergence is also important, especially during the winter. In most places, precipitation is largely balanced by thermodynamic energy divergence. Anomalously high surface temperatures appear to be mainly related to decreased surface evaporation. Anomalously high (low) precipitation variations may also be related to anomalously high thermodynamic energy divergence (convergence). Unfortunately, residual terms, which are slightly noticeable for the GCIP climatological balances, are especially noticeable for the anomalous atmospheric balances.