Journal Article

Influence of Kuroshio Extension’s sea surface temperature variability on the North Pacific atmosphere and Pacific Decadal Precession

Anderson, Bruce T., Silva, E. Nishchitha S.

2024

Overview

Recent research has revealed links between a quasi-decadal mode of climate variability over the North Pacific – the Pacific Decadal Precession (PDP) – and the North Pacific’s western boundary current’s extension – the Kuroshio Extension (KE). It is suggested that on decadal time scales the PDP both responds to and influences the KE variability. A question yet to be answered is whether it is the large-scale or the mesoscale variations of the KE region that link with the PDP evolution. Using high-resolution sea surface temperature data (1981–2018) from the global ocean Operational Sea Surface Temperature (SST) and Sea Ice Analysis, low-resolution Extended Reconstructed SST (ERSST) version 3b data (1949–2018), geopotential height reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction (NCEP) we find that it is the large-scale variations in the KE region that correlate best with the PDP-like response in the overlying and downstream atmosphere as compared to the mesoscale variations. In particular, the second mode of the large-scale KE region, which is characterized by the warming (cooling) of the ocean south (north) of the KE, sets up a PDP-like north-south atmospheric pressure dipole over the North Pacific Ocean by altering the large-scale baroclinicity of the atmosphere and zonal intensification of the subtropical jet stream. In turn, there is a reduction in the zonal propagation of stationary wave energy and an enhancement of the climatological zonal wave heights over North America, which results in a downstream response over the North American continent and the formation of a subsequent east-west pressure dipole over the North Pacific and North American continent. As a result, there is a strong correlation between large-scale SST variations in the KE region and the evolution of the PDP over the next three years.

• Publisher: Springer Berlin Heidelberg,Springer,Springer Nature B.V
• Subject: Atmosphere / Atmospheric pressure / Baroclinic mode / Baroclinity / Boundary currents / Climate / Climate cycles / Climate variability / Climatology / cooling / Dipoles / Distribution / Downstream / Dynamic height / Earth and Environmental Science / Earth Sciences / Environmental aspects / Evolution / Geophysics/Geodesy / Geopotential / Geopotential height / Influence / Jet stream / Measurement / Medium-range forecasting / Mesoscale phenomena / North America / Ocean circulation / Ocean currents / Ocean temperature / Oceanography / Oceans / Original Article / Pacific Ocean / Precession / prediction / Sea ice / Sea ice temperatures / Sea surface temperature / Sea surface temperature data / Sea surface temperature variability / Standing waves / Subtropical jet stream / surface water temperature / Temperature data / Temperature variability / Variability / Variation / water power / Wave energy / Wave height / Wave power / Wave propagation / Weather forecasting / Zonal waves