Future intensification of extreme Aleutian Low events and their climate impacts

• Main Authors: Giamalaki, Aikaterini, Beaulieu, Claudie, Henson, Stephanie, Martin, Adrian, Kassem, Hachem, Faranda, Davide
• Format: Conference Object
• Language: English
• Published: 2020
• Subjects: Pacific; aleutian low
• Online Access: https://eprints.soton.ac.uk/449768/

Sea level pressure extreme events have considerable effects on regional and global climatic and oceanic conditions. In the North Pacific, the Aleutian Low (AL) extreme deepenings have been linked to major marine abrupt changes and extreme weather patterns, leading to serious implications on environmental and socio-economic conditions. However, there is limited information on the future evolution of the AL extremes and their effects on atmosphere-ocean interaction. Here, we use a large ensemble from the Community Earth System Model to examine the development of the AL extreme events in historical runs and future simulations under the RCP8.5 scenario. We estimate dynamical proxies to quantify the frequency and persistence of these extremes and further examine their relationship with net heat flux through wavelet coherence. Our results reveal an intensification of the AL extreme events under the RCP8.5 future scenario. An increasing trend towards the positive phase of the Pacific-North American teleconnection pattern, one of the most influential climate patterns in the Northern Hemisphere extratropics, is also presented. The strengthened future AL extremes further increase the variability on net heat fluxes in the Kuroshio Extension, the most significant heat and energy flux area in the North Pacific. The increasing intensity and frequency of occurrence of AL extreme events may potentially cause irreversible changes in fisheries, ecosystems and weather of the Pacific region.