Future intensification of extreme Aleutian low events and their climate impacts

K. Giamalaki (1) , C. Beaulieu (2) , S. A Henson (3) , A. P Martin (3) , H. Kassem (1) , Davide Faranda (4, 5, 6, 7)

1 Ocean and Earth Science [Southampton]
2 UC Santa Cruz - University of California [Santa Cruz]
3 NOC - National Oceanography Centre [Southampton]
4 ESTIMR - Extrèmes : Statistiques, Impacts et Régionalisation
5 LMD - Laboratoire de Météorologie Dynamique (UMR 8539)
6 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
7 IPSL (FR_636) - Institut Pierre-Simon-Laplace

Extreme Aleutian Low (AL) events have been associated with major ecosystem reorganisations and unusual weather patterns in the Pacific region, with serious socio-economic consequences. Yet, their future evolution and impacts on atmosphere–ocean interactions remain uncertain. Here, a large ensemble of historical and future runs from the Community Earth System Model is used to investigate the evolution of AL extremes. The frequency and persistence of AL extremes are quantified and their connection with climatic variables is examined. AL extremes become more frequent and persistent under the RCP8.5 scenario, associated with changes in precipitation and air temperature patterns over North America. Future changes in AL extremes also increase the variability of the sea surface temperature and net heat fluxes in the Kuroshio Extension, the most significant heat and energy flux region of the basin. The increased frequency and persistence of future AL extremes may potentially cause substantial changes in fisheries and ecosystems of the entire Pacific region as a knock-on effect.

Domaines: Océan, Atmosphère; Climatologie

K. Giamalaki, C. Beaulieu, S. A Henson, A. P Martin, H. Kassem, et al.. Future intensification of extreme Aleutian low events and their climate impacts. Scientific Reports, 2021, 11, pp.18395. ⟨10.1038/s41598-021-97615-7⟩. ⟨hal-03345492⟩