Mass imbalance and climate sensitivity of Arctic glaciers and ice caps

• Main Author: Tepes, Paul Dan
• Other Authors: Gourmelen, Noel, Nienow, Peter, Bingham, Robert, other
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: The University of Edinburgh 2021
• Subjects: Glaciers and ice caps; Ice mass balance; Arctic climate; Swath processing; CryoSat-2; Arctic; Greenland; arctic cryosphere; glacier; Ice cap; Ice Sheet
• Online Access: https://hdl.handle.net/1842/37783; https://doi.org/10.7488/era/1059

Glaciers and ice caps are prominent features in the landscapes surrounding the Greenland Ice Sheet and in the archipelagos of the Arctic seas. Their dynamic response in mass and flow to climate variability makes them a visible and important expression of the changes that are affecting the Earth’s climate system. Arctic glaciers and ice caps are losing mass rapidly, a trend sustained over recent decades and that is expected to continue into the 21st century driven by climatic change and exacerbated by the amplification of polar warming relative to the planetary mean. Mass imbalance of Arctic land ice is a source of major concern given its impact on global sea level rise, ocean circulation, regional hydrology, and on the local ecosystems and communities, which are also impacted by these changes, with increased ecological, socio-economic and geopolitical pressures afflicting the region. To effectively mitigate and adapt to these environmental changes, the large-scale, continuous monitoring of the Arctic cryosphere has become essential, and satellite geodesy is a critical tool for estimating glacier and ice cap mass balance. In this thesis, seven years of CryoSat-2 high-resolution swath interferometric altimetry were utilised to investigate changes in the volume of Arctic glaciers and ice caps outside of Greenland between 2010 and 2017. From these data, a pan-Arctic assessment of mass imbalance was produced, and losses partitioned into signals associated with atmospheric processes and glacier dynamics. The sampled satellite observations provide a detailed picture of the response of Arctic glaciers and ice caps to climate forcing, eliciting contrasting patterns of change that are driven by a combination of oceanic and atmospheric forcing and by internal instabilities (glacier surges). Results show that between 2010 and 2017, Arctic glaciers and ice caps lost 609 ± 7 gigatonnes of ice, contributing 0.240 ± 0.007 millimetres per year to global sea level rise. While surface ablation is responsible for 87 % of losses ...