Organization: National Science Foundation (NSF)

Research Title: Water and Energy: Atmospheric, Vegetative and Earth Interactions (WEAVE)

Funding Level (millions of dollars):

FY94 8.1
FY95 8.9
FY96 8.7

Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Research Subcommittee (100%) NSTC Committee on Fundamental Science
(b) Environmental Issue: Global Change (40%); Natural Variability (30%); Climate Change (20%); Large-scale Changes in Land Use (10%)
(c) Research Activity: Understanding (100%)

Organizational Component:
Directorates for Biological Sciences and Geoscience
Division of Environmental Biology
National Science Foundation
4201 Wilson Boulevard
Arlington, VA 22230

Point of Contact:
Scott Collins
Phone: 703-306-1479

Research Goals:
To improve sufficiently the understanding of the Earth's hydrologic and energy cycles to allow assessments of the potential impact of human activities on those cycles and on the climate system in general.

Research Description:
Regional and global climate, and flora and fauna are determined in large measure by the Earth's hydrological water and energy cycles. Water is one of the primary means of energy transfer on Earth, and the principal link among the biological, earth and atmospheric components of the climate system. Key program objectives are to understand the complex interactions and feedbacks among these components in the overall system and to distinguish between effects of human activities and natural variability. Each component of the hydrologic and related geochemical cycles affects, and is affected by, the others. Surface characteristics, including vegetation and lithosphere, determine the rate and nature of water and energy exchanges with the atmosphere. Radiative fluxes, sensible and latent heat fluxes, and evapotranspiration are governed by the nature and state of the ecosystem and lithosphere including surface and subsurface water flow, soil moisture, and types and states of vegetation. Precipitation and clouds can be strongly influenced by surface properties and, at the same time, are intricately involved in biogeochemical cycles. In the longer term, the distribution of water vapor, clouds, and precipitation and related weather and climate, influence ecosystem dynamics and the evolution of land surface features. Distribution of vegetation, and vegetation dynamics are strongly governed by physical factors, such as soil moisture and climate dynamics, and the relative importance of these factors is a function of spatial scale. Vegetation also may impose strong feedbacks on hydrology and climate. One of the most challenging aspects of the program is to ascertain the range of spatial and temporal scales at which key interactions occur. The response and contribution of each "sphere" to the evolution of the others must be understood in order to adequately describe the global hydrologic cycle and ultimately to predict, or to assess the potential for, global change.

Program Interfaces:
WEAVE is linked to national (multi-agency) and international research programs directed at understanding global energy and water cycles. WEAVE is NSF's principal contribution to the Global Energy and Water Cycle Experiment (GEWEX) under the WMO's World Climate Research Program and a major component of IGBP's Biological Aspects of the Hydrological Cycle (BAHC) and Global Change and Terrestrial Ecosystems (GCTE). In addition, WEAVE also contributes to land and water management programs in the Corps of Engineers, DOI, FEMA, EPA, and related state agencies.

Program Milestones:
1995-1999. Develop methods to overcome the inherent temporal and spatial scale disparity among the key processes within the atmospheric, hydrologic and biological systems in order to accurately characterize the regional and global energy and water cycles and their roles in climate processes.

Policy Payoffs: Water plays central roles in the evolution and health of the land and ecosystems and in climate processes. Water also will be the focus of national and international policy decisions in the near term and beyond. Understanding the physical and biological processes that govern the distribution of water will be essential as input for economic planning and decisions relating to agriculture and forestry, desertification, energy needs, and biodiversity as well as the basis for understanding and eventual modeling and predicting long-term climate and global change.