On the linkage between future Arctic sea ice retreat, the large-scale atmospheric circulation and temperature extremes over Europe

• Main Author: Riebold, Johannes (Dr.)
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2023
• Subjects: ddc:550; Institut für Umweltwissenschaften und Geographie; Arctic; Arktis*; Climate change; Kara Sea; Sea ice
• Online Access: https://publishup.uni-potsdam.de/frontdoor/index/index/docId/60488; https://nbn-resolving.org/urn:nbn:de:kobv:517-opus4-604883; https://doi.org/10.25932/publishup-60488; https://publishup.uni-potsdam.de/files/60488/riebold_diss.pdf

Extreme weather and climate events are one of the greatest dangers for present-day society. Therefore, it is important to provide reliable statements on what changes in extreme events can be expected along with future global climate change. However, the projected overall response to future climate change is generally a result of a complex interplay between individual physical mechanisms originated within the different climate subsystems. Hence, a profound understanding of these individual contributions is required in order to provide meaningful assessments of future changes in extreme events. One aspect of climate change is the recently observed phenomenon of Arctic Amplification and the related dramatic Arctic sea ice decline, which is expected to continue over the next decades. The question to what extent Arctic sea ice loss is able to affect atmospheric dynamics and extreme events over mid-latitudes has received a lot of attention over recent years and still remains a highly debated topic. In this respect, the objective of this thesis is to contribute to a better understanding on the impact of future Arctic sea ice retreat on European temperature extremes and large-scale atmospheric dynamics. The outcomes are based on model data from the atmospheric general circulation model ECHAM6. Two different sea ice sensitivity simulations from the Polar Amplification Intercomparison Project are employed and contrasted to a present day reference experiment: one experiment with prescribed future sea ice loss over the entire Arctic, as well as another one with sea ice reductions only locally prescribed over the Barents-Kara Sea.% prescribed over the entire Arctic, as well as only locally over the Barent/Karasea with a present day reference experiment. The first part of the thesis focuses on how future Arctic sea ice reductions affect large-scale atmospheric dynamics over the Northern Hemisphere in terms of occurrence frequency changes of five preferred Euro-Atlantic circulation regimes. When compared to circulation regimes ...