Uncertainties in Mass Balance Estimates for Glaciers in Complex Topography - a Case Study on James Ross Island, Antarctic Peninsula
The Antarctic Ice Sheet is the largest reservoir of frozen freshwater, with an ice mass equivalent to ~58 m sea-level rise in the case of a complete melt. One of the strongest temperature increases on Earth was reported for the northern Antarctic Peninsula over the second half of the 20th century. T...
| Main Author: | |
|---|---|
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
2020
|
| Subjects: | |
| Online Access: | https://opus4.kobv.de/opus4-fau/frontdoor/index/index/docId/14816 https://nbn-resolving.org/urn:nbn:de:bvb:29-opus4-148168 https://opus4.kobv.de/opus4-fau/files/14816/DissertationStefanLippl-Seifert.pdf |
| Summary: | The Antarctic Ice Sheet is the largest reservoir of frozen freshwater, with an ice mass equivalent to ~58 m sea-level rise in the case of a complete melt. One of the strongest temperature increases on Earth was reported for the northern Antarctic Peninsula over the second half of the 20th century. Thus, accurate mass balance estimates of glaciers located in this region are necessary for projections of the future sea-level. Despite advances in the length of observation periods, the number of measurements, and the reduction of errors, the intercomparison of mass balance estimates derived from various methods still reveals considerable differences. This holds true even if the results are averaged over large spatial extents. This considerable uncertainty was visible, for example, in the recent review of the role of melt caused by the ocean or the stability of the East Antarctic Ice Sheet. In order to contribute to the improvement of glacier mass balance estimates, this study compares estimates by applying the input-output method, as well as the geodetic method on a local scale. The study site, James Ross Island, is located at the eastern side of the northern Antarctic Peninsula. It consists of a complex topography with a ~300 to 500 m high, almost vertical cliff separating the catchment areas from the marine-terminating outlets of many glaciers on the island. A special focus of this thesis is on the influence of the individual input variables propagated onto the error of the final mass balance estimate. Due to the harsh environmental conditions, many mass balance estimates in Antarctica rely only on remotely sensed data, such as that used in the geodetic method, which has the drawback of propagating potential errors if no validation data are available. In the scope of this thesis, in-situ measurements from several expeditions in Antarctica, which are necessary, especially for accurate estimates of the input-output method, are conducted. These in-situ data such as the ice thickness or meteorological variables ... |
|---|