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Terrestrial water storage: large-scale variability and impacts on the global carbon cycle
| Content Provider | Semantic Scholar |
|---|---|
| Author | Humphrey, Vincent |
| Copyright Year | 2017 |
| Abstract | Terrestrial water storage consists of all water reservoirs of the Earth system, including groundwater, soil moisture, land ice, surface waters, snow cover as well as water stored in the biosphere. Every year, natural variability in climatic conditions worldwide leads to droughts and floods which have significant impacts for ecosystems and societies. All water reservoirs act as natural buffers and balance these fluctuations by providing water supply during dry conditions and by storing water surplus after rain and snow events. However, these changes in terrestrial water storage do not only reflect a response to climate variability, they also feed back to the energy and carbon cycles, introducing a complex picture of inter-annual variability and delayed response mechanisms within the climate system. Since 2002, the Gravity Recovery And Climate Experiment (GRACE) satellites have provided the very first global observations of terrestrial water storage changes, allowing for entirely new analyses on the role of this variable for the Earth system and the degree to which human activities impact freshwater resources. However, while a large number of regional studies have provided a rich overview on individual aspects of water storage changes, there are still few global assessments of the sensitivity of terrestrial water storage to changes in atmospheric conditions. In addition, our understanding of how extremes in water storage feed back to the global energy and carbon cycles is still very uncertain. This is partly because some of these effects occur on inter-annual to decadal time scales and are therefore difficult to identify from the relatively short GRACE record. The overarching goal of this thesis, which is organized in three individual studies, is to resolve these important research gaps. The first study presented in this thesis provides a global survey of the spatial and temporal modes of variability found in GRACE observations of terrestrial water storage changes. An extensive review of the literature shows that these different modes of variability tend to coincide with different hydrological processes and can be partly related to changes in temperature and precipitation. In addition, most of the high-frequency GRACE signal can be explained by precipitation if an adequate averaging filter is applied to the daily precipitation time series. Based on these relationships, the second study makes use of historical precipitation and temperature data to reconstruct terrestrial water storage changes prior to the GRACE mission. The |
| File Format | PDF HTM / HTML |
| DOI | 10.3929/ethz-b-000273375 |
| Alternate Webpage(s) | https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/273375/Abstract_24696.pdf?isAllowed=y&sequence=4 |
| Alternate Webpage(s) | https://doi.org/10.3929/ethz-b-000273375 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
