Implications of extreme liquid precipitation events on permafrost degradation at Spitsbergen

• Main Author: Wenzel, Lisa
• Format: Thesis
• Language: unknown
• Published: Humboldt-Universität zu Berlin 2020
• Subjects: North Atlantic; Ny Ålesund; Ny-Ålesund; permafrost; Svalbard; Spitsbergen
• Online Access: https://epic.awi.de/id/eprint/53635/; https://epic.awi.de/id/eprint/53635/1/Bachelorthesis_LisaWenzel_final.pdf; https://hdl.handle.net/10013/epic.a360a7a6-abd8-41bc-9e21-95b90e0764af

The signals of the Arctic Amplification are manifold. Different climate developments like the increase in moisture and air temperature or the decrease of the snow cover can be observed. The Svalbard archipelago is one of the warmest areas in the Arctic. It lies at the end of the North Atlantic cyclone track which is the main source of energy for the Arctic. A warming-induced intensified hydrological cycle increases the frequency of cyclones in Svalbard and thereby the occurrence of extreme rain events, in particular in winter. Only a few publications investigated the changes of precipitation in accordance to the existing permafrost, which characterizes 40% of the archipelago. This study describes the development of (extreme) liquid precipitation in Spitsbergen and investigates the impact of extreme rain events in relation to the degradation of permafrost that already occurs due to the amplified warming. Therefore, meteorological data as well as topsoil temperature data of Ny-Ålesund (Spitsbergen) were analyzed for the period from 1999 to 2020. It confirms an actual increase of (extreme) liquid precipitation in general and in winter season. Further, an examination of distinct extreme events revealed a remarkable effect of extreme rainfall on topsoil temperature on a micro-level and indicates complex interactions of several environmental factors regarding the heat fluxes between the atmosphere and the ground. In particular rain-on-snow events have a noticeable impact on topsoil temperature and thereby influence the thermal state of the permafrost substantially.