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| Titel |
Mass contribution of ice sheets and land glaciers to sea level rise |
| VerfasserIn |
Ernst Schrama, Bert Wouters, Roelof Rietbroek, Wouter van de Wal |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250091396
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| Publikation (Nr.) |
 EGU/EGU2014-5688.pdf |
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| Zusammenfassung |
| Present day sea level rise is strongly influenced by density and mass changes in the oceans.
This paper focuses on the mass effect estimated from Gravity Research And Climate
Experiment (GRACE) level-2 data collected between Feb 2003 and June 2013. For this
purpose we implement a global mascon model consisting of 10242 elements where we solve
for geo-center motion, we replace a gravitational flattening term from a time series
determined by satellite laser ranging, and we rely on the GLDAS model to implement a
hydrologic correction on land. To validate the level of systematic errors on the mass loss rates
seen for Antarctica and Greenland we use several global isostatic adjustment (GIA) models
based on radially stratified (1D) Earth models. In those we allow for different viscosity
profiles with ice loads from different paleo ice heights. We also considered a new
set of 3D finite element GIA models for Antarctica that allow lateral variations
in the rheologic parameters in the set-up of the Earth model. Our conclusion is
that the ice sheets and land glaciers presently result in a global sea level change of
1.51 ± 0.10 mm/yr or 540 ± 34 Gt/yr. This estimate is more than half of the sea
level rise seen by satellite altimetry over the some time period (2.78 mm/yr). Since
altimetry observes a combination of steric and mass driven effects the conclusion is
that approximately 54% of the present day sea level change signal comes from
mass fluxes originating from ice sheets and land glaciers. Between 2003 and 2013
Greenland contributed 281 ± 19 Gt/yr whereby an increase in mass loss is seen since
2009. Antarctica contributed 95 ± 27 Gt/yr and it shows a steady acceleration in
the Amundsen sea sector. Dronning Maud land on East Antarctica has seen an
increase in mass since June 2009 counteracting the total Antarctic mass loss. In the
analyzed time frame land glaciers and ice caps have contributed 162 ± 11 Gt/yr. |
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