| Autor: |
Voigt, C., Sulzbach, R., Dobslaw, H., Weise, A., Timmen, L., Deng, Z., Reich, M., Stolarczuk, N., Peters, H., Fietz, M., Thomas, M., Flechtner, F. |
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| Zdroj: |
Geophysical Research Letters; 7/16/2024, Vol. 51 Issue 13, p1-9, 9p |
| Abstrakt: |
Non‐tidal ocean loading (NTOL) signals are known to be a significant source of geophysically induced noise in gravimetric and geodetic observations also far‐away from the coast and especially during extreme events such as storm surges. Operationally available corrections suffer from a low temporal and spatial resolution and reveal too small amplitudes on continental stations. Dedicated high‐resolution sea‐level modeling of the North and Baltic Sea provides an improved prediction of NTOL signals. Superconducting gravimeter and Global Navigation Satellite Systems observations on the small offshore island of Heligoland in the North Sea are used for an evaluation of the model values revealing largely increased correlations of up to 0.9 and signal reductions of up to 50% during a storm surge period of one month in January and February 2022. Evaluations on additional continental superconducting gravimeter stations also show significant improvements through the recommended high‐resolution modeling for improved signal separation further away from the coast. Plain Language Summary: Terrestrial gravimetry is a technique to monitor temporal variations of the gravity acceleration at the Earth's surface that are induced by mass variations and deformations caused by a large number of geophysical effects on very different temporal and spatial scales. Current applications of high social relevance are the estimation of terrestrial water storage variations under climate change conditions, for example, groundwater depletion or polar and alpine ice mass loss, as well as hazard and geothermal monitoring. Before analyzing such signals of interest, it is essential to separate all other signals included in the gravimetric observations usually on the basis of adequate models. Amongst these disturbing signals, NTOL is one of the smaller but still significant effects. Up to now, the available operational corrections show a weak correlation with gravimetric observations and their application does not lead to a significant reduction of the observational signal variation. This situation largely improves with a high‐resolution model for gravity observations on the North Sea island of Heligoland. The model results are also applied to gravity records that were observed further away from the coast to assess the benefits of the model for an improved signal separation even at continental stations. Key Points: High‐resolution ocean model of the North and Baltic Sea provides improved non‐tidal ocean loading signalsModel evaluation by geodetic observations on the island of Heligoland shows correlation of 0.9 and signal reduction of 50%Continental gravimetric stations further away from the coast benefit from high‐resolution model for an improved signal separation [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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