Time variations of land water storage from an inversion of 2 years of GRACE geoids

By Guillaume Ramillien, F. Frappart, Anny Cazenave, A. Güntner. 2005

206 citations recorded by the source corpus.

By delivering monthly maps of the gravity field, the GRACE project allows the determination of tiny time variations of the Earth's gravity and particularly the effects of fluid mass redistributions at the surface of the Earth. However, GRACE data represent vertically integrated gravity measurements, thus are the sum of all mass redistributions inside the Earth's system (atmosphere, oceans and continental water storage, plus solid Earth). In this paper, we apply a generalized least-squares inverse approach, previously developed by [1] [G. Ramillien, A. Cazenave, O. Brunau, Global time-variations of hydrological signals from GRACE satellite gravimetry, Geophys. J. Int. 158 (2004) 813–826.], to estimate, from the monthly GRACE geoids, continental water storage variations (and their associated uncertainties) over a 2-year time span (April 2002 to May 2004). Tests demonstrating the robustness of the method are presented, including the separation between liquid water reservoirs (surface waters+soil moisture+groundwaters) and snow pack contributions. Individual monthly solutions of total land water storage from GRACE, with a spatial resolution of ~660 km, are presented for the 2-year time span. We also derive the seasonal cycle map. We further estimate water volume changes over eight large river basins in the tropics and compare with model predictions. Finally, we attempt to estimate an average value of the evapotranspiration over each river basin, using the water balance equation which links temporal change in water volume to precipitation, evapotranspiration and runoff. Amplitudes of the GRACE-derived evapotranspiration are regionally consistent to the predictions of global hydrological models.

Subfields: Aerospace Engineering, Astronomy and Astrophysics, Oceanography

View Paper: https://www.semanticscholar.org/paper/f11e3e09904378f9613a52dfd89961fea8630fb6

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Citations in the corpus

Surface freshwater storage and dynamics in the Amazon basin during the 2005 exceptional drought (2012, methodology): “…from Level-2 GRACE solutions filtered using an independent component analysis (ICA) approach (Frappart et al 2010b, 2011b) are computed following Ramillien et al (2005): 1VTWS(t) = R 2 e ∑ j∈S 1htot(λj, ϕj, t) cos(ϕj)1λ1ϕ (2) where htot(λj, ϕj, t) is the anomaly of TWS at time t of the pixel of…”
Interannual variations of the mass balance of the Antarctica and Greenland ice sheets from GRACE (2006, methodology): “…changes in liquid and solid water mass inside the surface fluid envelopes (e.g., Tapley et al., 2004a,b; Wahr et al., 2004; Chambers et al., 2004; Ramillien et al., 2005; Schmidt et al., 2006), including the ice sheets mass change (Velicogna and Wahr, 2005; Velicogna and Wahr, 2006).”
Post‐processing removal of correlated errors in GRACE data (2006, background): “…of studies have exploited this relationship to make estimates of water storage variability, both on land and in the oceans [Swenson and Milly, 2006; Ramillien et al., 2005; Chen et al., 2005; Velicogna and Wahr, 2005; Tamisiea et al., 2005; Chambers et al., 2004; Tapley et al., 2004b; Wahr et al.,…”
Modeling deformation induced by seasonal variations of continental water in the Himalaya region: Sensitivity to Earth elastic structure (2011, methodology): “…water mass change drainage basins); and (3) outside leakage error or uncertainties due to the spectrum truncation up to cutoff degree 50 (yielding a spatial resolution of 300–400 km) that could represent up to 6% of the estimate of equivalent water height [Ramillien et al., 2005, 2006, 2008].”
Detection of Continental Hydrology and Glaciology Signals from GRACE: A Review (2008, methodology): “Since then, several post-launch studies have clearly demonstrated its capacity to monitor water storage variations (Wahr et al. 2004; Ramillien et al. 2004 ), as well as to estimate the mass balance of the ice sheets (Velicogna and Wahr 2006a, b; Ramillien et al. 2006a), to quantify water fluxes su”