The movement of water and associated energy within Earth's atmosphere, oceans and land, and the exchanges among these components are a major aspect of Earth's climate system. Accompanying the water cycle, there are large radiative and latent heat fluxes, and oceanic salt transports involved. Correct simulation of the global water cycle and the associated energy and other fluxes in global climate system models is an extremely challenging task, yet it is a prerequisite for these models to provide realistic simulations of current and future climates. The PI will analyze the global and large-scale water cycles in the Community Climate System Model (CCSM3), the Goddard Institute for Space Sciences (GISS) model and the Geophysical Fluid Dynamics Laboratory (GFDL) model, and compare them with available observations. He will examine the spatial and temporal (seasonal to interannual) variations in precipitation (amount, frequency, and intensity), cloudiness, oceanic evaporation, terrestrial evapotranspiration and runoff, streamflow, atmospheric and oceanic freshwater transports, tropics-extratropics water exchange, land-ocean water exchange, terrestrial water storage, as well as their variability associated with the El Nino-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO).
The broader impacts of the work are that it will aid in assessing the uncertainty of the future climate change projections and will guide future model development. This is important for environmental management and decision-making activities.
