A possible mechanism for the North Pacific regime shift in winter of 1998/1999

2013 ◽  
Vol 40 (16) ◽  
pp. 4380-4385 ◽  
Author(s):  
Hyun-Su Jo ◽  
Sang-Wook Yeh ◽  
Cheol-Ho Kim
Keyword(s):  
North Pacific ◽  
Regime Shift ◽  
The North ◽  
The North Pacific

Decadal changes in growth and recruitment of Pacific halibut (Hippoglossus stenolepis)

1999 ◽  
Vol 56 (2) ◽  
pp. 242-252 ◽  
Author(s):  
William G Clark ◽  
Steven R Hare ◽  
Ana M Parma ◽  
Patrick J Sullivan ◽  
Robert J Trumble
Keyword(s):  
North Pacific ◽  
Regime Shift ◽  
Assessment Model ◽  
Individual Growth ◽  
Climate Regime ◽  
Climate Regime Shift ◽  
The North ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
The North Pacific

Since the climate regime shift of 1976-1977 in the North Pacific, the individual growth of Pacific halibut (Hippoglossus stenolepis) has decreased dramatically in Alaska but not in British Columbia. Recruitment has increased dramatically in both areas. The decrease in age-specific vulnerability to commercial longline gear resulted in a persistent underestimation of incoming recruitment by the age-structured assessment method (CAGEAN) that was used to assess the stock. This problem has been corrected by adding temporal trends in growth and fishery selectivity to the assessment model. The recent sustained high level of recruitment at high levels of spawning biomass has erased the previous appearance of strong density dependence in the stock-recruitment relationship and prompted a reduction in the target full-recruitment harvest rate from 30-35 to 20-25%. The climate regime shift affected a number of other stocks of vertebrates and invertebrates in the North Pacific. While the general oceanographic changes have now been identified, the specific biological mechanisms responsible for the observed changes have not.

scholarly journals The 1976/77 North Pacific Climate Regime Shift: The Role of Subtropical Ocean Adjustment and Coupled Ocean–Atmosphere Feedbacks*

2005 ◽  
Vol 18 (23) ◽  
pp. 5125-5140 ◽  
Author(s):  
Lixin Wu ◽  
Dong Eun Lee ◽  
Zhengyu Liu
Keyword(s):  
Ocean Circulation ◽  
North Pacific ◽  
Regime Shift ◽  
Climate Regime ◽  
Climate Regime Shift ◽  
Modeling Approach ◽  
The North ◽  
Ocean Atmosphere ◽  
Decadal Climate ◽  
The North Pacific

Abstract In this study, a new modeling approach is used to look for potential causes of the North Pacific decadal climate regime shift. This new modeling approach is specifically designed to assess not only how changes of the wind-driven ocean circulation induce SST variability, but also the subsequent feedback to climate. Observations appear to indicate that the 1970s North Pacific climate regime shift may be attributed to the coupled ocean–atmosphere interaction over the North Pacific in response to persistent wind stress anomalies in the previous decade. This tends to be supported by modeling results, which suggest that the delayed adjustment of the subtropical ocean circulation may generate sea surface temperature (SST) anomalies in the western subtropical Pacific that may potentially induce a shift of atmospheric circulation, leading to a change of SST in the central and midlatitude North Pacific. This study appears to unify the recent contradictory views of the roles of ocean circulation in the North Pacific decadal climate variability.

scholarly journals VARIABILITY AND INTERRELATION OF THE BASIC CLIMATE INDICES FOR THE NORTH PACIFIC: TRENDS, CLIMATE SHIFTS, SPECTRA, CORRELATIONS

2019 ◽  
Vol 199 ◽  
pp. 163-178 ◽  
Author(s):  
G. V. Khen ◽  
E. I. Ustinova ◽  
Yu. D. Sorokin
Keyword(s):  
Time Series ◽  
North Pacific ◽  
Regime Shift ◽  
Spectral Power ◽  
Climate Indices ◽  
Siberian High ◽  
The North ◽  
Climate Shifts ◽  
The North Pacific

The study is continuing, which first results were published in 2019 [Khen et al., 2019]. The main patterns of long-term variability are considered for selected climate indices in the North Pacific and links between them are identified on the common methodological basis. The following indices are analyzed: AO (Arctic Oscillation), PDO (Pacific Decadal Oscillation), Nino 3.4 (index of El-Nino — South Oscillation), ALPI (Aleutian Low Pressure index), NPI (North Pacific index), PNA (Pacific/North American index), SHI (Siberian High index), and WP (West Pacific index). Their time-series are provided on websites of the world climate centers, with exception of the Siberian High index that was calculated from the reanalysis data on the sea level pressure provided by the USA National Center for Environmental Prediction (NCEP) — National Center for Atmospheric Research (NCAR) for 1950–2018. Data were analysed using standard statistical methods. Regime shifts are detected using Rodionov’s method of sequential regime shift detection including the regime shift index (RSI) and tools of automatic detection of the regime shifts with improved performance at the ends of time series. Variations of all indices since the middle 20th century correspond to warming that is not monotonous but combines phases of quick transition from one climatic regime to another — climate shifts and periods of relatively stable state between them. The most important climate shifts happened in 1977 and 1989 and they were noted for majority of the considered indices. Values of the indices heightened in the former shift and slightly lowered in the latter one, except of NPI that had opposite changes. PDO, WP and NPI had another positive shift in the recent years (2015–2017) that allows to assume transition to a new climate regime which will be warmer than the previous one in the last two decades. Long-term periodicity coincided with the 19-year cycle of lunar declination is revealed for PDO, ALPI, NPI and PNA; its spectral power amplifies considerably after removing of high-frequency variability by running 5-year averaging of the time series. Nino 3.4 showed a prominent 11-year cycle, possibly associated with the solar activity. SHI, AO and WP changed with periods about two decades: the main frequency is 26 years for SHI, 20 years for AO, and 17 years for WP, but the peaks of spectral power for the two latter indices is low, i.e. non-periodic oscillations dominate for them. Secondary peaks of spectral power are much lower than the main ones, they correspond to cycles of 7–8 years for AO and PDO, 11 years for WP, and 15 years for SHI. The indices of the North Pacific quartette (PDO, ALPI, NPI and PNA) are closely related between each other with high correlation coefficients (0.67–0.96). The Nino 3.4 index is also linked with them, but with lower correlation (0.45–0.56). SHI has statistically significant relationship with AO only, and WP correlates with Nino 3.4. Contribution of the large-scale climate processes to environmental variability in the Far-Eastern Seas of Russia and the Northwestern Pacific will be considered in the next issue.

scholarly journals Signatures of the 1976–1977 Regime Shift in the North Pacific Revealed by Statistical Analysis

2018 ◽  
Vol 123 (6) ◽  
pp. 4388-4397 ◽  
Author(s):  
K. Giamalaki ◽  
C. Beaulieu ◽  
D. Faranda ◽  
S. A. Henson ◽  
S. A. Josey ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
North Pacific ◽  
Regime Shift ◽  
The North ◽  
The North Pacific

scholarly journals A modelling study of the 1976 climate regime shift in the North Pacific Ocean

1999 ◽  
Vol 56 (12) ◽  
pp. 2450-2462 ◽  
Author(s):  
Julia Qiuying Wu ◽  
William W Hsieh
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
General Circulation ◽  
Regime Shift ◽  
North Pacific Ocean ◽  
Circulation Model ◽  
Climate Regime ◽  
Climate Regime Shift ◽  
The North ◽  
The North Pacific

Around 1976, the North Pacific Ocean underwent a climate regime shift, with significant biological consequences. To model the changes in the ocean, an ocean general circulation model was forced by the wind stress and sea surface temperature monthly climatology of the 1952-1975 period in one numerical experiment and the 1976-1988 period in another. Changes in the ocean model between the two experiments revealed how the ocean might have changed under the 1976 climate regime shift. In winter, the intensified post-1976 Aleutian Low spun up the subarctic gyre and the subtropical gyre, except in the Gulf of Alaska, where the circulation weakened. Upwelling was generally enhanced in the subarctic and downwelling enhanced in the subtropical region, with temperature changes down to 600 m. In the post-1976 period, the meridional heat transports were also enhanced: poleward in the low latitudes, equatorward in the midlatitudes, and poleward in the high latitudes.

scholarly journals Late‐1980s Regime Shift in the Formation of the North Pacific Subtropical Mode Water

2020 ◽  
Vol 125 (2) ◽  
Author(s):  
Sang‐Yeob Kim ◽  
Gyundo Pak ◽  
Ho Jin Lee ◽  
Young‐Oh Kwon ◽  
Young Ho Kim
Keyword(s):  
North Pacific ◽  
Regime Shift ◽  
Mode Water ◽  
Subtropical Mode Water ◽  
The North ◽  
The North Pacific
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