On the Relation Between Arctic Sea Ice and European Cold Winters During the Little Ice Age 1400-1850

• Main Author: Silver, Kristian
• Format: Bachelor Thesis
• Language: English
• Published: Uppsala universitet, Luft-, vatten- och landskapslära 2014
• Subjects: Barents Sea; Kara Sea; sea ice reduction; Arctic; midlatitudes; feedback effect; Last Millennium; historical climate change; climate modeling; threshold; global warming; cold winters; Little Ice Age; North Atlantic oscillation; LIA; NAO; PMIP3; CMIP5; NASA-GISS; Barents hav; Karahavet; reducerat istäcke; Arktis; mellanbredderna; återkopplingseffekt; historiska klimatförändringar; klimatmodellering; tröskeleffekt; global uppvärmning; kalla vintrar; "Lilla istiden"; Nordatlantiska oscillationen; Meteorology and Atmospheric Sciences; Meteorologi och atmosfärforskning; Climate Research; Klimatforskning; Kalla; Lilla; Arktis*; Climate change; Global warming; North Atlantic; Sea ice
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-223656

This study aims to investigate the possible historical correlation between sea ice reduction in the Arctic and cold winters in Central Europe. The study is conducted over a cold period in Europe known as the Little Ice Age (LIA), 1400–1850, and uses a Global Climate Model with eight different forcing scenarios. Temperature data from Central Europe and ice data from the Arctic are extracted from the model and compared. The assumed relationship has been presented in various forms in the last few years. Essentially, it is argued that less sea ice in a particular area in the Arctic (around the Barents and Kara Seas) could affect largescale atmospheric circulation patterns, including the North Atlantic oscillation (NAO), and then give rise to cold European winters. Thus, this essay also recreates the NAO over the same historical period. The results of this study are not, however, able to confirm this theory; over longer periods the identified correlation is rather the opposite. It is speculated that this mechanism could include a threshold, where it might not be noticeable for historical, heavier ice-conditions; but more so for future, global warming scenarios. However, a correlation tendency is identified in some of the model runs, suggesting that a feedback effect such as this, if it existed, might be more likely to affect temperatures of individual months rather than the entire winter. A very weak response is also found for the NAO itself. The model’s suitability for this kind of study is then discussed. Although it might not precisely capture each type of year-to-year comparison used in this study, it is proven to have some response to known individual events in climatological history. Finally, it is concluded that this study alone cannot disprove the proposed theory, and that further investigation is required. Denna studie syftar till att undersöka en möjlig historisk koppling mellan minskad havsis i Arktis och kalla vintrar i Centraleuropa. Studien undersöker en lång kallperiod i Europa, "Lilla istiden", som ...