H42D-03
The Potential for Forecasting Water Cycle Extremes with GRACE
Thursday, 17 December 2015: 10:50
3011 (Moscone West)
Matthew Rodell1, Benjamin F Zaitchik2, Augusto Getirana1,3, Bailing Li3,4, Sujay Kumar1, Hiroko K Beaudoing3,4, Himanshu Save5 and Srinivas V Bettadpur5, (1)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (2)Johns Hopkins University, Baltimore, MD, United States, (3)Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, United States, (4)NASA/GSFC, Greenbelt, MD, United States, (5)Center for Space Research, Austin, TX, United States
Abstract:
GRACE is able to quantify changes in terrestrial water storage (the sum of groundwater, soil moisture, surface waters, and snow), which makes it well suited for identifying both hydrological droughts, when terrestrial water storage is low, and floods, when terrestrial water storage is high. Several recent studies have explored the use of GRACE data for quantifying water cycle trends and extremes. In particular, fields of soil moisture and groundwater storage variations are being generated through the assimilation of GRACE data into a land surface model, and those results are used to produce wetness index maps that have been distributed from the U.S. National Drought Mitigation Center’s data portal since 2011. The objectives of this presentation are (1) to characterize wet and dry extremes around the world during the GRACE period (i.e., since 2002) in the context of other information on major floods and droughts; (2) to explore how data assimilation can be used to overcome GRACE’s low spatial and temporal resolutions (relative to other hydrological observations) and data latency, to make GRACE relevant for worldwide drought and flood monitoring; and (3) to outline steps now being taken to extrapolate the GRACE data assimilation results into the future in order to improve seasonal forecasts of regional droughts and floods in the continental U.S.
