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| Titel |
Variability in Terrestrial Water Storage and its effect on polar motion |
| VerfasserIn |
Justyna Śliwińska, Jolanta Nastula |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138282
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| Publikation (Nr.) |
 EGU/EGU2017-1258.pdf |
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| Zusammenfassung |
| Explaining the hydrological part of observed polar motion excitation has been a major
challenge over a dozen years. The terrestrial water storage (TWS) excitation of polar motion -
hydrological angular momentum (HAM), has been investigated widely using global
hydrological models mainly at seasonal timescales. Unfortunately, the results from the
models do not fully explain the role of hydrological signal in polar motion excitation. The
determination of TWS from the Earth’s gravity field observations represents an indirect
approach for estimating land hydrology. Throughout the past decade, the Gravity Recovery
and Climate Experiment (GRACE) has given an unprecedented view on global variations in
Terrestrial Water Storage.
Our investigations are focused on the influence of Terrestrial Water Storage (TWS)
variations obtained from Gravity Recovery and Climate Experiment (GRACE) mission on
polar motion excitation functions at decadal and inter-annual timescales. The global and
regional trend, seasonal cycle as well as some extremes in TWS variations are considered
here.
Here TWS are obtained from the monthly mass grids land GRACE Tellus data: GRACE
CSR RL05, GRACE GFZ RL05 and GRACE JPL RL05. As a comparative dataset, we also
use TWS estimates determined from the World Climate Research Programme’s Coupled
Model Intercomparison Project Phase 5 (CMIP5). GRACE data and state-of-the-art CMIP5
climate models allow us to show the variability of hydrological part of polar motion under
climate changes.
Our studies include two steps: first, the determination and comparisons of regional
patterns of TWS obtained from GRACE data and climate models, and second,
comparison of the regional and global hydrological excitation functions of polar motion
with a hydrological signal in the geodetic excitation functions of polar motion. |
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