Examining the Effects of Greenland Ice Sheet Melting and Atlantic Meridional Shutdown on the Climate of Scandinavia and the British Isles

• Main Author: Lemburg, Tyler
• Format: Text
• Language: unknown
• Published: DigitalCommons@University of Nebraska - Lincoln 2019
• Subjects: climatology; climate modeling; Earth Sciences; Oceanography and Atmospheric Sciences and Meteorology; Greenland; Rowe; Ice Sheet; North Atlantic; North Atlantic oscillation
• Online Access: https://digitalcommons.unl.edu/geoscidiss/124; https://digitalcommons.unl.edu/context/geoscidiss/article/1127/viewcontent/Thesis.pdf

Earth’s climate has been rapidly changing over the last hundred years, and its global average temperature is rising. However, climate change is far more complicated than a simple increase in temperature. For example, it is theorized that certain regions of Earth, including Scandinavia and the British Isles, could actually become cooler through ongoing climate change processes. Two of these processes are Greenland Ice Sheet (GrIS) melting, and slowdown of the Atlantic Meridional Overturning Circulation (AMOC). This research examines if climate change, through GrIS melting and AMOC slowdown, could contribute to cooler, instead of warmer, temperatures in Scandinavia and the British Isles. The Weather Research and Forecasting climate model (WRF) was used to emulate a slowdown of AMOC via a widespread \SI{5}{K} sea surface temperature decrease near the southern coast of Greenland. Although WRF contains a simple three-dimensional ocean model, this module was added relatively recently and was not used for this work. An experiment was run for a 1979-2009 time period over a domain covering Greenland, Scandinavia, and the British Isles, forced by the NCEP Climate Forecast System. Two runs were performed: a control run, and an experiment run including the sea surface temperature anomaly. The resulting climatologies showed a cooling of surface air temperature in Scandinavia and the British Isles of roughly \SI{0.1}{K} for the experiment run compared to the control run, with a larger difference present in winter months. The anomaly's effects were also linked with the state of the North Atlantic Oscillation. Other differences between the two runs included a lower tropopause for the region, drier air in Scotland and Scandinavia, and varying regional positive and negative differences of total precipitation and snow and ice, all again slightly more intense during colder months. It is surmised that GrIS melting and a slowdown of AMOC, when considered in isolation from other climate change effects, would lead to overall cooler ...