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Separation of water storage compartments of the continental hydrology from gravity and remote sensing dataMass transports and redistributions within the System Earth are caused by a huge number of processes, such as circulations in the oceans and the atmosphere, water fluxes between terrestrial water storages, river discharge or sea level changes. In the past, it was rather difficult or even impossible to observe changes of the mass distribution. Today, however, simultaneously operating satellite gravity and altimetry missions allow for the detection of mass transports and redistributions. Consequently, satellite gravity missions such as GRACE are sensitive to the hydrological cycle. The hydrological cycle describes the continuous water transport on, above, and below the surface of the Earth. Freshwater represents only about 3% of all water on Earth. Around 68% of the freshwater is stored as snow and ice on Antarctica and Greenland; 30% are stored as ground water. Lakes, streams and rivers account for only 0.3% of the Earth's freshwater.
According to the IPCC 2007 report the continental hydrology is still the most imprecise determined part of the global water cycle. Consequently improved models of the continental hydrology and its storage components have to developed. Since March 2002 the satellite mission GRACE allows for the first time to estimate total continental water storage change at large scales. In addition altimetry measurements over lakes, reservoirs and wetlands can be used to calculate water masses over continents. Remote sensing data can be used for the detection and floodings.
Selected publicationsSeitz F., Schmidt , M. : HYDROLOGICAL MASS VARIATIONS DUE TO EXTREME WEATHER SITUATIONS IN CENTRAL EUROPE FROM GLOBAL AND REGIONAL GRACE EXPANSIONS. n: Benveniste, J., P. Berry, S. Calmant, W. Grabs, P., Kosuth (Eds.): Proceedings of the 2nd Space for Hydrology Workshop "Surface Water Storage and Runoff: Modeling, In-Situ Data and Remote Sensing. ESA Publication WPP-280, Noordwijk, The Netherlands., 2007 Schmidt M., Seitz F., Shum C.K.: Regional four-dimensional hydrological mass variations from GRACE, atmospheric flux convergence, and river gauge data. Journal of Geophysical Research, 113, B10402, 10.1029/2008JB005575, 2008 Seitz F., Schmidt M., Shum C.K.: Signals of extreme weather conditions in Central Europe in GRACE 4D hydrological mass variations. Earth and Planetary Science Letters, 268, 165-170, DOI 10.1016/j.epsl.2008.01.001, 2008 |
