Searched for: author:"Schrama, E.J.O."
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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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Cazenave, Anny (author), Riva, R.E.M. (author), Schrama, E.J.O. (author)
Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows changes (e.g., acceleration) to be detected in one or more components. Study of the sea-level budget provides constraints on missing or...
journal article 2018
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Xu, Z. (author), Schrama, E.J.O. (author), van der Wal, W. (author), van den Broeke, MR (author), Enderlin, EM (author)
In this study, we use satellite gravimetry data from the Gravity Recovery and Climate Experiment (GRACE) to estimate regional mass change of the Greenland ice sheet (GrIS) and neighboring glaciated regions using a least squares inversion approach. We also consider results from the input–output method (IOM). The IOM quantifies the difference...
journal article 2016
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Dieng, Habib B. (author), Champollion, Nicolas (author), Cazenave, A. (author), Wada, Y (author), Schrama, E.J.O. (author), Meyssignac, B (author)
We estimate the total land water storage (LWS) change between 2003 and 2013 using a global water mass budget approach. Hereby we compare the ocean mass change (estimated from GRACE space gravimetry on the one hand, and from the satellite altimetry-based global mean sea level corrected for steric effects on the other hand) to the sum of the...
journal article 2015
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Xu, Z. (author), Schrama, E.J.O. (author), Van der Wal, W. (author), Van den Broeke, M. (author), Enderlin, E.M. (author)
In this study, we use satellite gravimetry data from the Gravity Recovery and Climate Experiment (GRACE) to estimate regional mass changes of the Greenland ice sheet (GrIS) and neighbouring glaciated regions using a least-squares inversion approach. We also consider results from the input-output method (IOM) that quantifies the difference...
journal article 2015
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Rietbroek, R. (author), Schrama, E.J.O. (author)
journal article 2015
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Mulder, G. (author), Olsthoorn, T.N. (author), Al-manmi, D.A.M.A. (author), Schrama, E.J.O. (author), Smidt, E.H. (author)
Observations acquired by Gravity Recovery And Climate Experiment (GRACE) mission indicate a mass loss of 146 ± 6 mm equivalent water height (EWH) in northern Iraq between 2007 and 2009. These data are used as an independent validation of lake mass variations and a rainfall-runoff model, which is based on local geology and climate conditions....
journal article 2015
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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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Mulder, G. (author), Olsthoorn, T.N. (author), Al-manmi, D.A.M.A. (author), Schrama, E.J.O. (author), Smidt, E.H. (author)
Observations acquired by Gravity Recovery And Climate Experiment (GRACE) mission indicate a mass loss of 31 ± 3 km3 or 130 ± 14 mm in Northern Iraq between 2007 and 2009. This data is used as an independent validation of a hydrologic model of the region including lake mass variations. We developed a rainfall–runoff model for five tributaries of...
journal article 2014
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Bouman, J. (author), Fuchs, M. (author), Ivins, E. (author), Van der Wal, W. (author), Schrama, E.J.O. (author), Visser, P.N.A.M. (author), Horwath, M. (author)
The orbit and instrumental measurement of the Gravity Field and Steady State Ocean Circulation Explorer (GOCE) satellite mission offer the highest ever resolution capabilities for mapping Earth's gravity field from space. However, past analysis predicted that GOCE would not detect changes in ice sheet mass. Here we demonstrate that GOCE gravity...
journal article 2014
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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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Bouman, J. (author), Fiorot, S. (author), Fuchs, M. (author), Gruber, T. (author), Schrama, E.J.O. (author), Tscherning, C.C. (author), Veicherts, M. (author), Visser, P.N.A.M. (author)
Two of the GOCE Level 2 products are the gravity gradients (GGs) in the Gradiometer Reference Frame (GRF) and the GGs in the Local North-Oriented Frame (LNOF). The GRF is an instrument frame and the GGs are derived from the L1b GGs. The L1b to L2 GG processing involves corrections for temporal gravity variations, outlier detection and data gap...
conference paper 2011
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Bouman, J. (author), Fiorot, S. (author), Fuchs, M. (author), Gruber, T. (author), Schrama, E.J.O. (author), Tscherning, C. (author), Veicherts, M. (author), Visser, P.N.A.M. (author)
GOCE is ESA’s gravity field mission and the first satellite ever that measures gravitational gradients in space, that is, the second spatial derivatives of the Earth’s gravitational potential. The goal is to determine the Earth’s mean gravitational field with unprecedented accuracy at spatial resolutions down to 100 km. GOCE carries a gravity...
journal article 2011
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Schrama, E.J.O. (author), Wouters, B. (author), Vermeersen, L.L.A. (author)
This paper summarizes results obtained for Greenland’s mass balance observed with NASA’s GRACE mission. We estimate a Greenland ice sheet mass loss at ?201 ± 19 Gt/year including a discernible acceleration of ?8 ± 7 Gt/year2 between March 2003 and February 2010. The mass loss of glacier systems on the South East of Greenland has slowed down...
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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Visser, P.N.A.M. (author), Schrama, E.J.O. (author), Sneeuw, N. (author), Weigelt, M. (author)
The so-called Colombo-Nyquist (Colombo, The global mapping of gravity with two satellites, 1984) rule in satellite geodesy has been revisited. This rule predicts that for a gravimetric satellite flying in a (near-)polar circular repeat orbit, the maximum resolvable geopotential spherical harmonic degree (lmax) is equal to half the number of...
conference paper 2009
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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
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Wouters, B. (author), Schrama, E.J.O. (author)
One of the major problems one has to deal with when working with Gravity Recovery and Climate Experiment (GRACE) data is the increasing error spectrum at higher degrees in the provided Stokes coefficients, appearing as unphysical North?South striping patterns in the maps of equivalent water height (EWH). This phenomenon is commonly suppressed by...
journal article 2007
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Schrama, E.J.O. (author), Wouters, B. (author), Lavallée, D.A. (author)
The Gravity Recovery and Climate Experiment (GRACE) product used for this study consists of 43 monthly potential coefficient sets released by the GRACE science team which are used to generate surface mass thickness grids expressed as equivalent water heights (EQWHs). We optimized both the smoothing radius and the level of approximation by...
journal article 2007
Searched for: author:"Schrama, E.J.O."
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