Intensification of future North Pacific extreme sea level pressure events and their oceanic response in a changing climate.

North Pacific sea level pressure (SLP) extreme events have considerable effects on regional and global climatic and oceanic conditions. Specifically, the Aleutian Low extreme events have been associated with major marine regime shifts and unusual weather patterns in North America and Eurasia, with serious socio-economic consequences. Yet, our knowledge about the future evolution of the Aleutian Low extremes and their subsequent oceanic response is limited. Here we use historical simulations and business-as-usual future projections of the large ensemble Community Earth System Model (CESM-LENS) to examine the North Pacific SLP behaviour and its oceanic response. Dynamical proxies are calculated using a combination of the extreme value theory and dynamical systems theory in order to detect North Pacific SLP extremes. Cross wavelet coherence is applied to identify the relationship of the extreme SLP events with net heat flux in the Kuroshio Extension. The results suggest that the amplified intensity and frequency of the Aleutian Low in the future also induces increased variability on the Kuroshio Extension net heat flux across a range of time scales. The strengthening of the AL and its profound effect on the North Pacific conditions under the pressure of continuous climate change is highlighted here. Such intensified future atmospheric extremes may lead to irreversible physical changes affecting fisheries, ecosystems as well as weather patterns in the whole Pacific region.