Relationship between the North Pacific Gyre Oscillation and the onset of stratospheric final warming in the northern Hemisphere

Abstract This study investigates the features of atmospheric circulation and moisture transport associated with two modes of decadal variability in the North Pacific: the Pacific decadal oscillation (PDO) and the North Pacific Gyre Oscillation (NPGO), with emphasis on the multiscale water vapor transport and atmospheric river (AR) over the North Pacific region. During the positive phase of PDO, the geopotential height anomaly at 500-hPa exhibits a Pacific–North American-like pattern. During the positive phase of NPGO, the geopotential height anomaly at 500 hPa features a dipole pattern with a negative anomaly north of 40°N and a positive anomaly south of 40°N over the North Pacific. Associated with the positive PDO phase, the ocean-to-land moisture transport is enhanced between 25° and 35°N and reduced over the northeastern Pacific (25°–62°N, 180°–110°W) for the time-mean integrated vapor transport (IVT). The synoptic poleward transport is suppressed north of 40°N and enhanced south of 40°N. In the positive NPGO phase, the zonal moisture transport is intensified south of 20°N and between 40° and 50°N for the time-mean IVT and weakened over the west coast of North America for the low-frequency (10–100 days) IVT. The synoptic poleward transport is suppressed south of 30°N. The eastern part of the North Pacific AR belt moves southward during positive PDO as the entire North Pacific AR belt shifts slightly northward during positive NPGO. An investigation of AR anomalies during a period over which the PDO and NPGO coexist demonstrates that the AR frequency over the North American western coastal regions is significantly influenced by the conjunction of the PDO and NPGO modes.

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North Pacific Gyre Oscillation Synchronizes Climate Fluctuations in the Eastern and Western Boundary Systems*

Journal of Climate ◽

10.1175/2009jcli2848.1 ◽

2009 ◽

Vol 22 (19) ◽

pp. 5163-5174 ◽

Cited By ~ 98

Author(s):

Lina I. Ceballos ◽

Emanuele Di Lorenzo ◽

Carlos D. Hoyos ◽

Niklas Schneider ◽

Bunmei Taguchi

Keyword(s):

North Pacific ◽

Dominant Mode ◽

Subtropical Gyre ◽

Western Boundary ◽

North Pacific Subtropical Gyre ◽

Climate Fluctuations ◽

The North ◽

North Pacific Gyre Oscillation ◽

North Pacific Gyre ◽

The North Pacific

Abstract Recent studies have identified the North Pacific Gyre Oscillation (NPGO) as a mode of climate variability that is linked to previously unexplained fluctuations of salinity, nutrient, and chlorophyll in the northeast Pacific. The NPGO reflects changes in strength of the central and eastern branches of the subtropical gyre and is driven by the atmosphere through the North Pacific Oscillation (NPO), the second dominant mode of sea level pressure variability in the North Pacific. It is shown that Rossby wave dynamics excited by the NPO propagate the NPGO signature in the sea surface height (SSH) field from the central North Pacific into the Kuroshio–Oyashio Extension (KOE), and trigger changes in the strength of the KOE with a lag of 2–3 yr. This suggests that the NPGO index can be used to track changes in the entire northern branch of the North Pacific subtropical gyre. These results also provide a physical mechanism to explain coherent decadal climate variations and ecosystem changes between the North Pacific eastern and western boundaries.

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The North Pacific Gyre Oscillation and Mechanisms of Its Decadal Variability in CMIP5 Models

Journal of Climate ◽

10.1175/jcli-d-17-0344.1 ◽

2018 ◽

Vol 31 (6) ◽

pp. 2487-2509 ◽

Cited By ~ 1

Author(s):

Daling Li Yi ◽

Bolan Gan ◽

Lixin Wu ◽

Arthur J. Miller

Keyword(s):

North Pacific ◽

Time Scale ◽

Decadal Variability ◽

Low Frequency ◽

Coupled Model ◽

Cmip5 Models ◽

The North ◽

North Pacific Gyre Oscillation ◽

North Pacific Gyre ◽

The North Pacific

Based on the Simple Ocean Data Assimilation (SODA) product and 37 models from phase 5 of the Coupled Model Intercomparison Project (CMIP5) database, the North Pacific Gyre Oscillation (NPGO) and its decadal generation mechanisms are evaluated by studying the second leading modes of North Pacific sea surface height (SSH) and sea level pressure (SLP) as well as their dynamical connections. It is found that 17 out of 37 models can well simulate the spatial pattern and decadal time scales (10–30 yr) of the NPGO mode, which resembles the observation-based SODA results. Dynamical connections between the oceanic mode (NPGO) and the atmospheric mode [North Pacific Oscillation (NPO)] are strongly evident in both SODA and the 17 models. In particular, about 30%–40% of the variance of the NPGO variability, which generally exhibits a preferred time scale, can be explained by the NPO variability, which has no preferred time scale in most models. Two mechanisms of the decadal NPGO variability that had been proposed by previous studies are evaluated in SODA and the 17 models: 1) stochastic atmospheric forcing and oceanic spatial resonance and 2) low-frequency atmospheric teleconnections excited by the equatorial Pacific. Evaluation reveals that these two mechanisms are valid in SODA and two models (CNRM-CM5 and CNRM-CM5.2), whereas two models (CMCC-CM and CMCC-CMS) prefer the first mechanism and another two models (CMCC-CESM and IPSL-CM5B-LR) prefer the second mechanism. The other 11 models have no evident relations with the proposed two mechanisms, suggesting the need for a fundamental understanding of the decadal NPGO variability in the future.

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HOT and the North Pacific gyre

Nature ◽

10.1038/378022a0 ◽

1995 ◽

Vol 378 (6552) ◽

pp. 22-22 ◽

Cited By ~ 2

Author(s):

David M. Karl

Keyword(s):

North Pacific ◽

The North ◽

North Pacific Gyre ◽

The North Pacific

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Source-receptor relationships between East Asian sulfur dioxide emissions and Northern Hemisphere sulfate concentrations

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-5537-2008 ◽

2008 ◽

Vol 8 (2) ◽

pp. 5537-5561 ◽

Cited By ~ 6

Author(s):

J. Liu ◽

D. L. Mauzerall ◽

L. W. Horowitz

Keyword(s):

Northern Hemisphere ◽

North Pacific ◽

East Asian ◽

Source Region ◽

The United States ◽

So2 Emissions ◽

Aerosol Model ◽

The North ◽

The North Pacific ◽

Sulfur Emissions

Abstract. We analyze the effect of varying East Asian (EA) sulfur emissions on sulfate concentrations in the Northern Hemisphere, using a global coupled oxidant-aerosol model (MOZART-2). We conduct a base and five sensitivity simulations, in which sulfur emissions from each continent are tagged, to establish the source-receptor (S-R) relationship between EA sulfur emissions and sulfate concentrations over source and downwind regions. We find that from west to east across the North Pacific, EA sulfate contributes approximately 80%–20% of sulfate at the surface, but at least 50% at 500 hPa. In addition, EA SO2 emissions account for approximately 30%–50% and 10%–20% of North American background sulfate over the western and eastern US, respectively. The contribution of EA sulfate to the western US at the surface is highest in MAM and JJA, but is lowest in DJF. Reducing EA SO2 emissions will significantly decrease the spatial extent of the EA sulfate influence over the North Pacific both at the surface and at 500 mb in all seasons, but the extent of influence is insensitive to emission increases, particularly in DJF and JJA. We find that EA sulfate concentrations over most downwind regions respond nearly linearly to changes in EA SO2 emissions, but sulfate concentrations over the EA source region increase more slowly than SO2 emissions, particularly at the surface and in winter, due to limited availability of oxidants (mostly H2O2). We find that similar estimates of the S-R relationship for trans-Pacific transport of EA sulfate would be obtained using either sensitivity or tagging techniques. Our findings suggest that future changes in EA sulfur emissions may cause little change in the sulfate induced health impact over downwind continents but SO2 emission reductions may significantly reduce the sulfate related climate cooling over the North Pacific and the United States.

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