Non-Tidal Atmosphere and Ocean Background Modelling for Satellite Gravimetry: Development of AOD1B RL07
The satellite gravimetry missions GRACE and its successor GRACE-FO measure large-scale mass redistributions in the Earth system, including changes in terrestrial water storage, ice shelves, the oceans and atmosphere as well as the solid Earth. As the measurements are typically accumulated over one m...
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| Other Authors: | , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
2023
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| Online Access: | https://refubium.fu-berlin.de/handle/fub188/44041 https://doi.org/10.17169/refubium-43750 https://nbn-resolving.org/urn:nbn:de:kobv:188-refubium-44041-7 |
| Summary: | The satellite gravimetry missions GRACE and its successor GRACE-FO measure large-scale mass redistributions in the Earth system, including changes in terrestrial water storage, ice shelves, the oceans and atmosphere as well as the solid Earth. As the measurements are typically accumulated over one month before the computation of a gravity solution, high-frequency mass variations need to be accounted for using a-priori background models. The Atmosphere and Ocean Dealiasing Level 1B (AOD1B) data product routinely provides the necessary simulated non-tidal mass variations in the atmosphere and oceans. While progress towards better background models has been made over the past years, residual errors in the simulated atmospheric and oceanic mass variations are still among the largest limiting factors to the overall GRACE accuracy. As a result, further improvements of these data-products are directly linked to improvements in the final gravity solutions and thus subsequent geophysical analyses. This thesis summarizes the most recent improvements to the AOD1B product, including an updated ocean model configuration considering the effects of self-attraction and loading, an updated atmospheric component as well as an improved post-processing and tidal analysis. All of these changes are shown to result in a better representation of the simulated mass variations and are thus combined into a new release RL07 of AOD1B. Additionally, the new release is examined in terms of its stability and consistency over long and short time-scales. Spurious trends, low-frequency signals or bias jumps in the background model data can, if unaccounted for, introduce biases into the global gravity solutions which are prone to be interpreted erroneously in subsequent geophysical analyses. Consequently, the analysis focuses on signals that might be induced into the final gravity field solutions such as trends but also possible discontinuities caused by changes is the employed atmospheric datasets. It is shown that AOD1B RL07 is free from such ... |
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