scholarly journals On the Observed Relationships between Wintertime Variability in Kuroshio–Oyashio Extension Sea Surface Temperatures and the Atmospheric Circulation over the North Pacific

2018 ◽  
Vol 31 (12) ◽  
pp. 4669-4681 ◽  
Author(s):  
Samantha M. Wills ◽  
David W. J. Thompson
Keyword(s):  
Atmospheric Circulation ◽  
North Pacific ◽  
Sea Surface ◽  
Western Boundary ◽  
Turbulent Heat ◽  
Sea Surface Temperatures ◽  
The North ◽  
Surface Temperatures ◽  
The North Pacific ◽  
Sst Anomalies

Observational analyses reveal that wintertime variations in sea surface temperatures (SST) in the Kuroshio–Oyashio Extension (KOE) region of the North Pacific are associated with two distinct and robust patterns of atmospheric variability: 1) a pattern that peaks in amplitude approximately 2–3 weeks prior to large KOE SST anomalies and is consistent with atmospheric forcing of the SST field and 2) a very different pattern that lags SST anomalies in the KOE region by approximately a month. The latter pattern is dominated by low sea level pressure anomalies and turbulent heat fluxes directed into the atmosphere over warm SST anomalies and is interpreted as the transient atmospheric response to SST anomalies over the KOE region. The results contribute to a growing body of evidence that suggests variations in SSTs in the midlatitude oceans are capable of significantly influencing the large-scale atmospheric circulation, especially near western boundary currents.

The Influence of ENSO on the Generation of Decadal Variability in the North Pacific*

2007 ◽  
Vol 20 (4) ◽  
pp. 667-680 ◽  
Author(s):  
Soon-Il An ◽  
Jong-Seong Kug ◽  
Axel Timmermann ◽  
In-Sik Kang ◽  
Oliver Timm
Keyword(s):  
El Niño ◽  
North Pacific ◽  
Decadal Variability ◽  
El Nino ◽  
Sea Surface ◽  
Diagnostic Study ◽  
Sea Surface Temperatures ◽  
The North ◽  
Surface Temperatures ◽  
The North Pacific

Abstract This diagnostic study explores the generation of decadal variability in the North Pacific resulting from the asymmetry of the El Niño–Southern Oscillation phenomenon and the nonlinearity of the atmospheric tropical–extratropical teleconnection. Nonlinear regression analysis of the North Pacific sea surface temperatures and atmospheric fields with respect to the ENSO index reveals that the main teleconnection centers shift between El Niño and La Niña years. This asymmetry in the ENSO response, together with the skewed probabilistic distribution of ENSO itself, may contribute to the generation of the long-term decadal variability of sea surface temperatures in the extratropical North Pacific. It is argued that this hypothesis may explain the significant variance of the observed Pacific decadal oscillation in the extratropics.

Recent intensified influence of the winter North Pacific sea surface temperature on the withdrawal date of Meiyu

2021 ◽  
pp. 1-53
Author(s):  
Hua Li ◽  
Shengping He ◽  
Ke Fan ◽  
Yong Liu ◽  
Xing Yuan
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Interannual Variability ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Sea Surface ◽  
The North ◽  
Time Period ◽  
The North Pacific ◽  
Sst Anomalies

AbstractThe Meiyu withdrawal date (MWD) is a crucial indicator of flood/drought conditions over East Asia. It is characterized by a strong interannual variability, but its underlying mechanism remains unknown. We investigated the possible effects of the winter sea surface temperature (SST) in the North Pacific Ocean on the MWD on interannual to interdecadal timescales. Both our observations and model results suggest that the winter SST anomalies associated with the MWD are mainly contributed by a combination of the first two leading modes of the winter SST in the North Pacific, which have a horseshoe shape (the NPSST). The statistical results indicate that the intimate linkage between the NPSST and the MWD has intensified since the early 1990s. During the time period 1990–2016, the NPSST-related SST anomalies persisted from winter to the following seasons and affected the SST over the tropical Pacific in July. Subsequently, the SST anomalies throughout the North Pacific strengthened the southward migration of the East Asian jet stream (EAJS) and the southward and westward replacement of the western North Pacific subtropical high (WPSH), leading to an increase in Meiyu rainfall from July 1 to 20. More convincingly, the anomalous EAJS and WPSH induced by the SST anomalies can be reproduced well by numerical simulations. By contrast, the influence of the NPSST on the EASJ and WPSH were not clear between 1961 and 1985. This study further illustrates that the enhanced interannual variability of the NPSST may be attributed to the more persistent SST anomalies during the time period 1990–2016.

Sign in / Sign up

Export Citation Format

Share Document