Monitoring Changes in Continental Water Storage with GRACE
The Gravity Recovery and Climate Experiment, GRACE, will enable the recovery of monthly estimates of changes in water storage, on land and in the ocean, avenged over arbitrary regions having length scales of a few hundred km and larger. These data will allow the examination of changes in the distribution of water in the ocean, in snow and ice on polar ice sheets, and in coniinental waler and snow storage. Extracting changes in waler storage from the GRACE dataset requires the use of averaging kernels which can isolate a particular region. To estimate the accuracy to which continental water storage changes in a few representative regions may be recovered, we construct a synthetic GRACE dataset from global, gridded models of surface-mass variability. We find that regional changes in water storage can be recovered with rms error less than 1 cm of equivalent water thickness, for regions having areas of 4 × l05 km2 and larger. Signals in smaller regions may also be recovered; however, interpretations of such results require a careful consideration of model resolution, as well as the nature of the averaging kernel.
KeywordsAverage Kernel Mississippi River Basin Equivalent Water Thickness Grace Data Snow Storage
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- Dukowicz. J.K.. and R.D. Smith: 1994. Implicit free-surface method for the Bryan-Cox-Semtner ocean model, f. Geaphvs Res. 99. 7991–8014.Google Scholar
- Entin. J.. A. Rohock, K. Vinnikov. S. Hollinger, S. Liu. and A. Namkhai: 2(100. Temporal and spatial scales of observed soil moisture variations in the extratropies. i. Geophvs. Pt’s. 105(D9). 11. 865–11, 877.Google Scholar
- GRACE Science and Mission Requiwmen!s Document: 2001. GRACE 327–200. JPL PuN. 0–15928. Rev. 0.Google Scholar
- Milly. P.C.D.. and A.B. Shmakin: 2001. Global modeling of land water and energy balances: 1. The Land Dynaniies (LaD) Model, submitted to Journal of Hydrometcorology.Google Scholar
- Swenson, S., and J. Wahr: 2002, Methods for inferring regional surt’ace-mass anomalies from GRACE measurements of time-variable gravity. I Geophys. Rca. 107 (B9). 2193, doi: l0.l029l200lJB000576Google Scholar
- Swenson. S.. and J. Wahr: 2002. Estimated effects of the vertical structure of atmospheric mass on the time-variable geoid..1. Geophy.t Pt’s. 107(139). 2194. doi: 10.1 0291200t)JB000024.Google Scholar
- Velicogna. I.. J. Wahr. and H. van den Dool: 2001, Can surface pressure be used to remove atmospheric contributions from GRACE data with sufficient accuracy to recover hydrological signals?. I Geophvs. Pt’s1106(B8). 16, 415–16. 434.Google Scholar
- Wahr. J.. M. Molcnaar. and F. Bryan: 1998, lime variability of the Earth’s gravity Field: Hydrological and oceanic effects and their possible detection using GRACE. J. Geophvs Pt’s. 103 (1312), 30, 205–30, 229.Google Scholar
- Watkins, M. M., W.M. Folkner, B. F. Chao, and B. D. Tapley: 1999. The Proposed NASA EX-5 Mission: A Laser Interferomctcry Successor to GRACE, Eos Trans AGU 80(46), Nov. 16, 1999.Google Scholar