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Kleinherenbrink, M. (author), Riva, R.E.M. (author), Frederikse, T. (author), Merrifield, Mark (author), Wada, Yoshihide (author)The mass and steric components of sea level changes have been separated in the Tropical Asian Seas (TAS) using a statistically optimal combination of Jason satellite altimetry, GRACE satellite gravimetry, and ocean reanalyses. Using observational uncertainties, statistically optimally weighted time series for both components have been...journal article 2017
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Simon, K.M. (author), Riva, R.E.M. (author), Kleinherenbrink, M. (author), Tangdamrongsub, N. (author)Geodetic measurements of vertical land motion and gravity change are incorporated into an a priori model of present-day glacial isostatic adjustment (GIA) in North America via least-squares adjustment. The result is an updated GIA model wherein the final predicted signal is informed by both observational data, and prior knowledge (or...journal article 2017
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Ran, J. (author), Ditmar, P.G. (author), Klees, R. (author), Farahani, H. (author)We present an improved mascon approach to transform monthly spherical harmonic solutions based on GRACE satellite data into mass anomaly estimates in Greenland. The GRACE-based spherical harmonic coefficients are used to synthesize gravity anomalies at satellite altitude, which are then inverted into mass anomalies per mascon. The limited...journal article 2017
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De Teixeira Da Encarnação, J. (author), Arnold, Daniel (author), Bezděk, Aleš (author), Dahle, Christoph (author), Doornbos, E.N. (author), van den IJssel, J.A.A. (author), Jäggi, Adrian (author), Mayer-Gürr, Torsten (author), Sebera, Josef (author), Visser, P.N.A.M. (author), Zehentner, Norbert (author)It is of great interest to numerous geophysical studies that the time series of global gravity field models derived from Gravity Recovery and Climate Experiment (GRACE) data remains uninterrupted after the end of this mission. With this in mind, some institutes have been spending efforts to estimate gravity field models from alternative...journal article 2016
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Tangdamrongsub, N. (author), Ditmar, P.G. (author), Steele-Dunne, S.C. (author), Gunter, B.C. (author), Sutanudjaja, E. H. (author)In this study, satellite observations including gravity (GRACE), terrestrial reflectance (MODIS), and global precipitation (TRMM) data, along with the output from the PCR-GLOBWB hydrological model, are used to generate monthly and sub-monthly terrestrial water storage (TWS) estimates and quantify flood events over the Tonlé Sap basin between...journal article 2016
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Fuchs, Martin Johann (author), Hooper, Andrew (author), Broerse, D.B.T. (author), Bouman, Johannes (author)The Gravity Recovery and Climate Experiment (GRACE) mission (launched 2002) and the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) mission (March 2009 to November 2013) collected spaceborne gravity data for the preseismic and postseismic periods of the 2011 Tohoku-Oki earthquake. In addition, the dense Japan GeoNet Global...journal article 2016
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Van der Wal, W. (author), Whitehouse, P.L. (author), Schrama, E.J.O. (author)Seismic data indicate that there are large viscosity variations in the mantle beneath Antarctica. Consideration of such variations would affect predictions of models of Glacial Isostatic Adjustment (GIA), which are used to correct satellite measurements of ice mass change. However, most GIA models used for that purpose have assumed the mantle to...journal article 2015
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Schrama, E.J.O. (author), Wouters, B. (author), Rietbroek, R. (author)The purpose of this paper is to assess the mass changes of the Greenland Ice Sheet (GrIS), Ice Sheets over Antarctica, and Land glaciers and Ice Caps with a global mascon method that yields monthly mass variations at 10,242 mascons. Input for this method are level 2 data from the Gravity Recovery and Climate Experiment (GRACE) system collected...journal article 2014
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Ivins, E.R. (author), James, T.S. (author), Wahr, J. (author), Schrama, E.J.O. (author), Landerer, F.W. (author), Simon, K.M. (author)Antarctic volume changes during the past 21 thousand years are smaller than previously thought, and here we construct an ice sheet history that drives a forward model prediction of the glacial isostatic adjustment (GIA) gravity signal. The new model, in turn, should give predictions that are constrained with recent uplift data. The impact of the...journal article 2013
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Han, S.C. (author), Riva, R.E.M. (author), Sauber, J. (author), Okal, E. (author)We quantify gravity changes after great earthquakes present within the 10 year long time series of monthly Gravity Recovery and Climate Experiment (GRACE) gravity fields. Using spherical harmonic normal-mode formulation, the respective source parameters of moment tensor and double-couple were estimated. For the 2004 Sumatra-Andaman earthquake,...journal article 2013
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Huang, J. (author), Halpenny, J. (author), Van der Wal, W. (author), Klatt, C. (author), James, T.S. (author), Rivera, A. (author)Groundwater is a primary hydrological reservoir of the Great Lakes Water Basin (GLB), which is an important region to both Canada and US in terms of culture, society and economy. Due to insufficient observations, there is a knowledge gap about groundwater storage variation and its interaction with the Great Lakes. The objective of this study is...journal article 2012
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Broerse, D.B.T. (author), Vermeersen, L.L.A. (author), Riva, R.E.M. (author), Van der Wal, W. (author)Large earthquakes do not only heavily deform the crust in the vicinity of the fault, they also change the gravity field of the area affected by the earthquake due to mass redistribution in the upper layers of the Earth. Besides that, for sub-oceanic earthquakes deformation of the ocean floor causes relative sea level changes and mass...journal article 2011
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Schrama, E.J.O. (author), Wouters, B. (author)In this paper we discuss a new method for determining mass time series for 16 hydrological basins representing the Greenland system (GS) whereby we rely on Gravity Recovery and Climate Experiment (GRACE) mission data. In the same analysis we also considered observed mass changes over Ellesmere Island, Baffin Island, Iceland, and Svalbard (EBIS)....journal article 2011
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Wouters, B. (author), Riva, R.E.M. (author), Lavallée, D.A. (author), Bamber, J.L. (author)Variations in the Earth's water cycle are commonly quantified by their effect on global mean sea?level. However, the interaction between passive adjustment of the ocean to changes in gravitational attraction due to mass redistribution, the related deformation of the solid Earth and disturbances in the Earth's rotation vector will yield a...journal article 2011
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Lavallée, D.A. (author), Moore, P. (author), Clarke, P.J. (author), Petrie, E.J. (author), Van Dam, T. (author), King, M.A. (author)Changes in J2, resulting from past and present changes in Earth's climate, are traditionally observed by Satellite Laser ranging (SLR). Assuming an elastic Earth, it is possible to infer changes in J2 from changes in Earth's shape observed by GPS. We compare estimates of non-secular J2 changes from GPS, SLR, GRACE, and a load model. The GPS and...journal article 2010
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Riva, R.E.M. (author), Bamber, J.L. (author), Lavallée, D.A. (author), Wouters, B. (author)The Gravity Recovery and Climate Experiment satellites (GRACE) provide, for the first time, a method to directly measure mass exchange between the land and oceans over time. The dominant components of this exchange are due to continental ice loss/gain and land hydrology. Here, we determine the secular trend in these two components during the...journal article 2010
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Gunter, B. (author), Urban, T. (author), Riva, R. (author), Helsen, M. (author), Harpold, R. (author), Poole, S. (author), Nagel, P. (author), Schutz, B. (author), Tapley, B. (author)In this study, we present a comparison of coincident GRACE and ICESat data over Antarctica. The analysis focused on the secular changes over a 4-year period spanning from 2003 to 2007, using the recently reprocessed and publicly available data sets for both missions. The results show that the two independent data sets possess strong spatial...journal article 2009
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Duan, X.J. (author), Guo, J.Y. (author), Shum, C.K. (author), Van der Wal, W. (author)We revisit the empirical moving window filtering method of Swenson and Wahr (Geophys Res Lett 33:L08402, 2006) and its variants, Chambers (Geophys Res Lett 33:L17603, 2006) and Chen et al. (Geophys Res Lett 34: L13302, 2007), for reducing the correlated errors in the Stokes coefficients (SCs) of the spherical harmonic expansion of the GRACE...journal article 2009
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Klees, R. (author), Liu, X. (author), Wittwe, T. (author), Gunter, B.C. (author), Revtova, E.A. (author), Tenzer, R. (author), Ditmar, P. (author), Winsemius, H.C. (author), Savenije, H.H.G. (author)When using GRACE as a tool for hydrology, many different gravity field model products are now available to the end user. The traditional spherical harmonics solutions produced from GRACE are typically obtained through an optimization of the gravity field data at the global scale, and are generated by a number of processing centers around the...journal article 2008
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Wouters, B. (author), Chambers, D. (author), Schrama, E.J.O. (author)Using satellite gravity data between February 2003 and January 2008, we examine changes in Greenland's mass distribution on a regional scale. During this period, Greenland lost mass at a mean rate of 179 ± 25 Gt/yr, equivalent to a global mean sea level change of 0.5 ± 0.1 mm/yr. Rates increase over time, suggesting an acceleration of the mass...journal article 2008