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| Titel |
Antarctic snow accumulation variability related to ENSO from GRACE |
| VerfasserIn |
Ingo Sasgen, Henryk Dobslaw, Zdeněk Martinec, Maik Thomas |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250032914
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| Zusammenfassung |
| Interannual variations in Antarctic snow accumulation are important for understanding the
relation between the evolution of the Antarctic ice sheet and changes in the global climate
system. In situ measurements from, e.g., stakes, near-surface ice cores or ground-penetrating
radar are sparse and often merely locally representative. Observations from satellite laser and
radar remote sensing are confined to detect surface properties such as height or roughness,
requiring additional information about the interior of the snow pack to relate these
measurements to ice mass. Here, we present interannual variations of the ice mass along
the Antarctic Peninsula and in the Amundsen Sea Sector recovered for the years
2002 until 2008 from satellite gravimetry data of the Gravity Recovery and Climate
Experiment (GRACE). For both regions, mass anomalies derived from the time
series of GRACE gravity fields correlate well (r-0.8) with accumulation variations
estimated from freshwater fluxes from the European Centre for Medium Range
Weather Forecasts. Moreover, the mass anomalies for Antarctic Peninsula and in the
Amundsen Sea Sector are anti-correlated in time (r--0.5) and contain El Niño Southern
Oscillation signatures caused by the temporary existence of the Amundsen Sea
low-pressure system governing West Antarctic atmospheric moisture transports. The
GRACE-determined interannual ice-mass variations exhibit root-mean squared
amplitudes of ~Â 15.5±5.0 (AP) and 23.5±10.5Â Gt (AS), which are significant compared
to the mean annual mass loss of -109.3±6.9Â Gt in the coastal West Antarctica. |
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