Efforts to understand climate variability and predict future climate change have highlighted many aspects of the hydrologic cycle and the exchange of energy and water at the atmosphere-surface interface as areas of critically needed study. The very nature of weather and climate demands that an international perspective and a comprehensive research approach be applied to understand these important issues. In response to this need, the international partners of the World Climate Research Program developed GEWEX (Global Energy and Water Experiment) as a major focus of international study. As the first of five continental-scale experiments, the GEWEX Continental Scale International Project (GCIP) was established to quantitatively assess the hydrologic cycle and energy fluxes of the Mississippi River basin. GCIP focuses on understanding the annual, interannual, and spatial variability of hydrology and climate within the Mississippi River basin; the development and evaluation of regional coupled hydrologic/atmospheric models; the development of data assimilation schemes; and the development of accessible, comprehensive databases. Improved water resource management on seasonal to interannual time scales is also a key GCIP goal. This book reviews the GCIP program, describes progress to date, and explores promising opportunities for future progress.

A comprehensive treatment of models and processes related to water fluxes for meteorologists, hydrologists and oceanographers.

This paper documents version 1 of the Finite-volume Atmospheric Model of the IAP/LASG (FAMIL1), which has a flexible horizontal resolution up to a quarter of 1°. The model, currently running on the ''Tianhe 1A'' supercomputer, is the atmospheric component of the third-generation Flexible Global Ocean-Atmosphere-Land climate System model (FGOALS3) which will participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6). In addition to describing the dynamical core and physical parameterizations of FAMIL1, this paper describes the simulated characteristics of energy and water balances and compares them with observational/reanalysis data. The comparisons indicate that the model simulates well the seasonal and geographical distributions of radiative fluxes at the top of the atmosphere and at the surface, as well as the surface latent and sensible heat fluxes. A major weakness in the energy balance is identified in the regions where extensive and persistent marine stratocumulus is present. Analysis of the global water balance also indicates realistic seasonal and geographical distributions with the global annual mean of evaporation minus precipitation being approximately 10−5 mm d−1. We also examine the connections between the global energy and water balance and discuss the possible link between the two within the context of the findings from the reanalysis data. Finally, the model biases as well as possible solutions are discussed.