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Wouters, B. (author), Gardner, Alex S. (author), Moholdt, Geir (author)
Glaciers outside of the ice sheets are known to be important contributors to sea level rise. In this work, we provide an overview of changes in the mass of the world's glaciers, excluding those in Greenland and Antarctica, between 2002 and 2016, based on satellite gravimetry observations of the Gravity Recovery and Climate Experiment (GRACE)....
journal article 2019
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Groh, Andreas (author), Horwath, Martin (author), Horvath, Alexander (author), Meister, Rakia (author), Wouters, B. (author), Ditmar, P.G. (author), Ran, J. (author), Klees, R. (author), Schrama, E.J.O. (author)
Satellite gravimetry data acquired by the Gravity Recovery and Climate Experiment (GRACE) allows to derive the temporal evolution in ice mass for both the Antarctic Ice Sheet (AIS) and the Greenland Ice Sheet (GIS). Various algorithms have been used in a wide range of studies to generate Gravimetric Mass Balance (GMB) products. Results from...
journal article 2019
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Sun, Y. (author), Riva, R.E.M. (author), Ditmar, P.G. (author), Rietbroek, Roelof (author)
We present a new approach to estimate time variations in J2. Those variations are represented as the sum of contributions from individual sources. This approach uses solely Gravity Recovery And Climate Experiment (GRACE) data and the geoid fingerprints of mass redistributions that take place both at the surface and in the interior of the solid...
journal article 2019
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Ditmar, P.G. (author)
Time-varying Stokes coefficients estimated from GRACE satellite data are routinely converted into mass anomalies at the Earth’s surface with the expression proposed for that purpose by Wahr et al. (J Geophys Res 103(B12):30,205–30,229, 1998). However, the results obtained with it represent mass transport at the spherical surface of 6378 km...
journal article 2018
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Ditmar, P.G. (author), Tangdamrongsub, N. (author), Ran, J. (author), Klees, R. (author)
We propose a technique to regularize a GRACE-based mass-anomaly time-series in order to (i) quantify the Standard Deviation (SD) of random noise in the data, and (ii) reduce the level of that noise. The proposed regularization functional minimizes the Month-to-month Year-to-year Double Differences (MYDD) of mass anomalies. As such, it does...
journal article 2018
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Zhang, Hongyue (author), Sun, Y. (author)
Annual cycles in the geocenter motion time series are primarily driven by mass changes in the Earth’s hydrologic system, which includes land hydrology, atmosphere, and oceans. Seasonal variations of the geocenter motion have been reliably determined according to Sun et al. (J Geophys Res Solid Earth 121(11):8352–8370, 2016) by combining the...
journal article 2018
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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 Encarnacao, J.G. (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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