177 The Role of Large-Scale Field Experiments in Water and Energy Balance Studies
Part 15. Global Hydrology
Published Online: 15 APR 2006
Copyright © 2005 John Wiley & Sons, Ltd
Encyclopedia of Hydrological Sciences
How to Cite
Shuttleworth, W. J. and Gash, J. H. 2006. The Role of Large-Scale Field Experiments in Water and Energy Balance Studies. Encyclopedia of Hydrological Sciences. 15:177.
- Published Online: 15 APR 2006
Over the last two decades, increased awareness of the potential importance of anthropogenic drivers of “global change” and growing interest in predicting climate variability at seasonal to interannual timescales has stimulated the development of new experimental techniques and new modeling methods to upscale conventional observations of land-surface exchanges to area scales consistent with the grid scales used in General Circulation Models, and large-scale experiments in important global biomes that had previously been neglected. The nature, purpose, and scale of such large-scale field experiments, many fostered by international programs such as the World Climate Research Programme (WCRP) and the International Geosphere-Biosphere Programme (IGBP), has evolved with time. Initial studies focused on exploring the value of remotely sensed data when upscaling or provided data at several sites that sampled the most important vegetation covers across large biomes. One important class of experiments, the Mesoscale Field Experiments, laid emphasis on gathering data over an area comparable with that of a Global Circulation Model (GCM) grid square and explored the nature and significance of mesoscale coupling between the land surface and the overlying atmosphere and, in particular, the response of the atmosphere to heterogeneity in vegetation cover. Subsequently, the spatial scale of studies increased in a suite of Continental-Scale Experiments (CSEs) which explored the extent to which the atmospheric component of energy and water budgets can be reconciled with the equivalent surface budgets, fostered improvement in the performance of the regional scale–coupled hydrometeorological models, and investigated “land memory” processes that operate at regional scale and at the seasonal timescales. Recently the emphasis has been on seeking to link several CSEs together in a Coordinated Enhanced Observing Period (CEOP) using satellite systems to provide observations at the global scale. This article describes the evolving purpose and developing nature of large-scale field experiments over the period 1984–2004 and their role in providing improved knowledge and modeling of land-surface energy exchanges.
- continental-scale experiment;
- international experiment;
- international programs;
- land/atmosphere interaction;
- meso-scale experiment