A regime shift in North Pacific annual mean sea surface temperature in 2013/14

Abstract

This study revealed a new regime shift in the North Pacific annual mean sea surface temperature (SST) in 2013/14, robust in multiple SST data sets. This regime shift shows a horseshoe pattern with warming SST along the North American western coast and toward the Central Pacific. It suggests a phase reversal of the Victoria Mode (VM) and it seems unrelated to the shift in the Pacific Decadal Oscillation (PDO) and Interdecadal Pacific Oscillation (IPO). Associated with this regime shift, the annual surface air temperature significantly enhanced over the high-latitude landmass after 2014, whereas it declined over northeastern Canada and southwestern Greenland. The annual precipitation generally increased (decreased) in the Northern (Southern) Hemisphere landmass monsoon regions. There are no regime shifts in Equatorial Central-East Pacific SST and the intensity and locations of the Aleutian Low around 2013/14. These facts suggest the regime shift of North Pacific SST in 2013/14 may not originate from the decadal variations of the midlatitude atmosphere and tropical ocean. The extensive influence of this regime shift in 2013/14 on the atmospheric, oceanic and ecological systems warrants further investigation.

Regime shift of the leading mode of winter surface wind speed in northwest China in 2003/04 and its possible link with Barents–Kara sea ice

“…A regime shift is generally defined as a rapid transition from one mean state to another one in a time series (Rodionov, 2004; Xiao et al, 2012; Xiao & Li, 2007, 2011). A moving t ‐test technique is wildly used to detect the regime shift in a time series of ocean or atmosphere variable (Xiao et al, 2012, 2021; Xiao & Li, 2007, 2011; Xiao & Ren, 2021, 2023). Xiao and Li (2007) developed a moving t ‐test method by fulfilling the effective freedom degree correction, normal distribution skewness and kurtosis test and multiple testing corrections to better detect the regime shift in the ocean and atmosphere systems.…”

“…In this study, we employed the moving t ‐test method to examine the regime shift in a time series. The detailed introduction of the moving t ‐test technique are presented in the studies of Xiao and Li (2007) and Xiao and Ren (2023). If the mean value of a time series after the regime shift is larger (smaller) than the previous one, this regime shift is called as the increasing (decreasing) one in this study.…”

Seasonal prediction and possible causes of sudden losses of sea-ice in the Weddell Sea in recent years based on potential oceanic and atmospheric factors

“…A new regime shift occurred in 2013/14 (Xiao and Ren, 2023), which preceded the sudden losses of Weddell Sea SIC and might have influenced it. However, the PDO could not capture this regime shift.…”