Glacier elevation change from SAR interferometry - Glacier mass change and volume reconstruction from remote sensing acquisitions in the European Alps and subpolar & polar regions

• Main Author: Sommer, Christian
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2022
• Subjects: ddc:500; Arctic; Climate change
• Online Access: https://opus4.kobv.de/opus4-fau/frontdoor/index/index/docId/21156; https://nbn-resolving.org/urn:nbn:de:bvb:29-opus4-211563; https://opus4.kobv.de/opus4-fau/files/21156/csommer_thesis_DruckVer.pdf

Mountain glaciers and ice caps are important indicators of global climate change. Within past dec-ades, a substantial loss of ice volume has been observed in most of the Earth´s mountain regions and glaciers have been one the largest contributors to global sea level rise. Providing storage of fresh water, glaciers are an integral part of the hydrological cycle of mountain regions. Changes in meltwa-ter discharge can have widespread impact on river runoff, hydropower and irrigation, particularly in arid and semiarid regions. Therefore, knowledge of regional and global glacier evolution is essential to predict future changes in hydrology, freshwater availability and sea level change. Due to the remoteness of many mountain and polar regions and vast glacierized areas, glacier change measurements from field surveys usually involve high logistical efforts and are limited to a relatively small number of glaciers. To bridge the gap between local in-situ records of glacier mass balance and global estimates of mass changes in the cryosphere, space-borne remote sensing sensors provide large-scale observation capabilities of glacier-specific and regional volume changes. Since the second half of the 20th century, a growing number of data acquisitions with high spatial and temporal resolu-tion has become available with the launch of different earth observation satellite missions. In this thesis, applications of remote sensing acquisitions, primarily from spaceborne bistatic radar, to esti-mate glacier volume changes and reconstruct glacier volumes are shown. Surface elevation and mass changes of mountain glaciers and ice caps in different regions are measured from digital elevation models (DEMs) within three studies. This thesis provides novel estimates of the regions of South Georgia and the Russian High Arctic. Previous observations of glacier change were relatively sparse and limited to some glacier areas in both regions. The mass change rates calculated for glaciers and ice caps in South Georgia amount to -2.3±0.2 Gt a-1 ...