Modulation of Atmospheric Response to North Pacific SST Anomalies under Global Warming: A Statistical Assessment

Abstract In this study the modulation of ocean-to-atmosphere feedback over the North Pacific in early winter from global warming is investigated based on both the observations and multiple climate model simulations from a statistical perspective. It is demonstrated that the basin-scale atmospheric circulation displays an equivalent barotropic ridge in response to warm SST anomalies in the Kuroshio–Oyashio Extension (KOE) region. This warm SST–ridge response in early winter can be enhanced significantly by global warming, indicating a strengthening of air–sea coupling over the North Pacific. This enhancement is likely associated with the intensification of storm tracks and, in turn, the amplification of atmospheric transient eddy feedback in a warm climate, although the secular trend of enhanced storm-track activity over the North Pacific is suggested to be biased in reanalysis product.

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Importance of Resolving Kuroshio Front and Eddy Influence in Simulating the North Pacific Storm Track

Journal of Climate ◽

10.1175/jcli-d-16-0154.1 ◽

2017 ◽

Vol 30 (5) ◽

pp. 1861-1880 ◽

Cited By ~ 44

Author(s):

Xiaohui Ma ◽

Ping Chang ◽

R. Saravanan ◽

Raffaele Montuoro ◽

Hisashi Nakamura ◽

...

Keyword(s):

North Pacific ◽

Large Scale ◽

Climate Model ◽

Kuroshio Extension ◽

Storm Track ◽

Small Scale ◽

Low Resolution ◽

The North ◽

The North Pacific ◽

Sst Anomalies

Abstract Local and remote atmospheric responses to mesoscale SST anomalies associated with the oceanic front and eddies in the Kuroshio Extension region (KER) are studied using high- (27 km) and low-resolution (162 km) regional climate model simulations in the North Pacific. In the high-resolution simulations, removal of mesoscale SST anomalies in the KER leads to not only a local reduction in cyclogenesis but also a remote large-scale equivalent barotropic response with a southward shift of the downstream storm track and jet stream in the eastern North Pacific. In the low-resolution simulations, no such significant remote response is found when mesoscale SST anomalies are removed. The difference between the high- and low-resolution model simulated atmospheric responses is attributed to the effect of mesoscale SST variability on cyclogenesis through moist baroclinic instability. It is only when the model has sufficient resolution to resolve small-scale diabatic heating that the full effect of mesoscale SST forcing on the storm track can be correctly simulated.

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Assessing the Importance of Prominent Warm SST Anomalies over the Midlatitude North Pacific in Forcing Large-Scale Atmospheric Anomalies during 2011 Summer and Autumn

Journal of Climate ◽

10.1175/jcli-d-13-00140.1 ◽

2014 ◽

Vol 27 (11) ◽

pp. 3889-3903 ◽

Cited By ~ 13

Author(s):

Satoru Okajima ◽

Hisashi Nakamura ◽

Kazuaki Nishii ◽

Takafumi Miyasaka ◽

Akira Kuwano-Yoshida

Keyword(s):

North Pacific ◽

General Circulation ◽

Large Scale ◽

Storm Track ◽

Anticyclonic Anomaly ◽

The North ◽

Basin Scale ◽

Sst Anomaly ◽

The North Pacific ◽

Sst Anomalies

Abstract Sets of atmospheric general circulation model (AGCM) experiments are conducted to assess the importance of prominent positive anomalies in sea surface temperature (SST) observed over the midlatitude North Pacific in forcing a persistent basin-scale anticyclonic circulation anomaly and its downstream influence in 2011 summer and autumn. The anticyclonic anomaly observed in October is well reproduced as a robust response of an AGCM forced only with the warm SST anomaly associated with the poleward-shifted oceanic frontal zone in the midlatitude Pacific. The equivalent barotropic anticyclonic anomaly over the North Pacific is maintained under strong transient eddy feedback forcing associated with the poleward-deflected storm track. As the downstream influence of the anomaly, abnormal warmth and dryness observed over the northern United States and southern Canada in October are also reproduced to some extent. The corresponding AGCM response over the North Pacific to the tropical SST anomalies is similar but substantially weaker and less robust, suggesting the primary importance of the prominent midlatitude SST anomaly in forcing the large-scale atmospheric anomalies observed in October 2011. In contrast, the model reproduction of the atmospheric anomalies observed in summer was unsuccessful. This appears to arise from the fact that, unlike in October, the midlatitude SST anomalies accompanied reduction of heat and moisture release from the ocean, indicative of the atmospheric thermodynamic forcing on the SST anomalies. Furthermore, the distinct seasonality in the AGCM responses to the warm SST anomalies may also be contributed to by the seasonality of background westerlies and storm track.

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A New Look at Snowpack Trends in the Cascade Mountains

Journal of Climate ◽

10.1175/2009jcli2911.1 ◽

2010 ◽

Vol 23 (10) ◽

pp. 2473-2491 ◽

Cited By ~ 26

Author(s):

Mark T. Stoelinga ◽

Mark D. Albright ◽

Clifford F. Mass

Keyword(s):

Time Series ◽

Global Warming ◽

Pacific Northwest ◽

North Pacific ◽

Climate Model ◽

North Pacific Ocean ◽

Tropospheric Temperature ◽

Anthropogenic Global Warming ◽

The North ◽

The North Pacific

Abstract This study examines the changes in Cascade Mountain spring snowpack since 1930. Three new time series facilitate this analysis: a water-balance estimate of Cascade snowpack from 1930 to 2007 that extends the observational record 20 years earlier than standard snowpack measurements; a radiosonde-based time series of lower-tropospheric temperature during onshore flow, to which Cascade snowpack is well correlated; and a new index of the North Pacific sea level pressure pattern that encapsulates modes of variability to which Cascade spring snowpack is particularly sensitive. Cascade spring snowpack declined 23% during 1930–2007. This loss is nearly statistically significant at the 5% level. The snowpack increased 19% during the recent period of most rapid global warming (1976–2007), though this change is not statistically significant because of large annual variability. From 1950 to 1997, a large and statistically significant decline of 48% occurred. However, 80% of this decline is connected to changes in the circulation patterns over the North Pacific Ocean that vary naturally on annual to interdecadal time scales. The residual time series of Cascade snowpack after Pacific variability is removed displays a relatively steady loss rate of 2.0% decade−1, yielding a loss of 16% from 1930 to 2007. This loss is very nearly statistically significant and includes the possible impacts of anthropogenic global warming. The dates of maximum snowpack and 90% melt out have shifted 5 days earlier since 1930. Both shifts are statistically insignificant. A new estimate of the sensitivity of Cascade spring snowpack to temperature of −11% per °C, when combined with climate model projections of 850-hPa temperatures offshore of the Pacific Northwest, yields a projected 9% loss of Cascade spring snowpack due to anthropogenic global warming between 1985 and 2025.

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Mechanisms for the Maintenance of the Wintertime Basin-Scale Atmospheric Response to Decadal SST Variability in the North Pacific Subarctic Frontal Zone

Journal of Climate ◽

10.1175/jcli-d-17-0200.1 ◽

2017 ◽

Vol 31 (1) ◽

pp. 297-315 ◽

Cited By ~ 6

Author(s):

Satoru Okajima ◽

Hisashi Nakamura ◽

Kazuaki Nishii ◽

Takafumi Miyasaka ◽

Akira Kuwano-Yoshida ◽

...

Keyword(s):

North Pacific ◽

Frontal Zone ◽

Atmospheric Response ◽

The North ◽

Model Response ◽

Basin Scale ◽

Sst Anomaly ◽

Subarctic Frontal Zone ◽

The North Pacific ◽

Sst Anomalies

Abstract Mechanisms for the maintenance of a large-scale wintertime atmospheric response to warm sea surface temperature (SST) anomalies associated with decadal-scale poleward displacement of the North Pacific subarctic frontal zone (SAFZ) are investigated through the following two ensemble experiments with an atmospheric general circulation model (AGCM): one with climatological-mean SST and the other with positive SST anomalies along the SAFZ prescribed on top of the climatological-mean SST. As actually observed, the simulated January ensemble response over the North Pacific is anticyclonic throughout the depth of the troposphere, although its amplitude is smaller. This response is maintained through energy conversion from the ensemble climatological-mean circulation realized under the climatological SST as well as feedback from anomalous transient eddy activity, suggesting that the response may have characteristics as a preferred mode of variability (or “dynamical mode”). Conversions of both available potential energy and kinetic energy from the climatological-mean state are important for the observed anomaly, while the latter is less pronounced for the model response. Net transient feedback forcing is also important for both the observed anomaly and simulated response. These results imply that a moderate-resolution (~1°) AGCM may be able to simulate a basin-scale atmospheric response to the SAFZ SST anomaly through synoptic- and basin-scale dynamical processes. Weaker PNA-like internal variability in the model may lead to the weaker response, suggesting that misrepresentation of intrinsic atmospheric variability can affect the model response to the SST anomaly.

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Untangling impacts of global warming and Interdecadal Pacific Oscillation on long-term variability of North Pacific tropical cyclone track density

Science Advances ◽

10.1126/sciadv.aba6813 ◽

2020 ◽

Vol 6 (41) ◽

pp. eaba6813 ◽

Cited By ~ 1

Author(s):

Jiuwei Zhao ◽

Ruifen Zhan ◽

Yuqing Wang ◽

Shang-Ping Xie ◽

Qiong Wu

Keyword(s):

Global Warming ◽

Tropical Cyclone ◽

North Pacific ◽

Climate Model ◽

Track Density ◽

Interdecadal Pacific Oscillation ◽

Internal Climate Variability ◽

The North ◽

Climate Model Simulations

How much the observed long-term variability of tropical cyclone (TC) activity is due to anthropogenic global warming (GW) or internal climate variability remains unclear, limiting the confidence in projected future change in TC activity. Here, the relative contributions of GW and the Interdecadal Pacific Oscillation (IPO) to the long-term variability of TC track density (TCTD) over the North Pacific (NP) are quantified on the basis of statistical analyses and climate model simulations. Results show that historical GW mainly reduced (increased) TCTD over the western (eastern) NP, while the positive (negative) IPO corresponds to a NP basin–wide increase (decrease) in TCTD except in some coastal regions. The IPO has a much greater impact on TCTD over the western NP than GW, while the IPO and GW impacts are about equal over the eastern NP during 1960–2019. These findings have important implications for projecting future TC activity over the NP.

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Atmospheric Responses and Feedback to the Meridional Ocean Heat Transport in the North Pacific

Journal of Climate ◽

10.1175/jcli-d-16-0055.1 ◽

2017 ◽

Vol 30 (15) ◽

pp. 5715-5728 ◽

Cited By ~ 1

Author(s):

Hiroaki Tatebe ◽

Masao Kurogi ◽

Hiroyasu Hasumi

Keyword(s):

Heat Transport ◽

North Pacific ◽

Climate Model ◽

Global Climate ◽

Global Climate Model ◽

Storm Track ◽

Ocean Heat Transport ◽

The North ◽

The Mean ◽

The North Pacific

Atmospheric responses and feedback to meridional ocean heat transport (OHT) have been investigated using a global climate model that is interactively connected with a high-resolution regional ocean model embedded in the western North Pacific. Compared with a global climate model without the regional model, the net heat supply into the Kuroshio–Oyashio Extension (KOE) region is increased as a result of the increase of the mean northward ocean heat transport (OHT) by the western boundary currents and mesoscale eddies. Resultant sea surface temperature (SST) rise sharpens the meridional SST gradient and reinforces the cross-frontal difference of the surface heat flux and thereby enhances lower-tropospheric baroclinicity. These changes cause northward deflection and strengthening of the wintertime storm track over the North Pacific, which leads to the Pacific–North American (PNA)-like pattern anticyclonic response of the mean westerly jet. The increase of the eddy northward atmospheric heat flux (AHF) associated with the enhanced storm-track activity is compensated by the decrease of the mean northward AHF. The changes of the atmospheric circulations reduce the mean northward OHT in the eastern North Pacific that compensates the increase of the mean northward OHT in the KOE region. The atmospheric responses, which have once been excited by the SST fronts in the KOE region, stabilize the trans–North Pacific OHT. The modeling results herein suggest that basinwide Bjerknes-like compensation works in air–sea coupled processes for the formation of the climatic mean state in the North Pacific.

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Impact of Sea Surface Temperature Anomalies in the Equatorial and North Pacific on the Arctic Stratosphere According to INMCM5 Climate Model Simulations

Meteorologiya i Gidrologiya ◽

10.52002/0130-2906-2021-1-5-16 ◽

2021 ◽

pp. 5-16

Author(s):

P. N. Vargin ◽

◽

M. A. Kolennikova ◽

S. V. Kostrykin ◽

E. M. Volodin ◽

...

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

North Pacific ◽

Climate Model ◽

Sea Surface ◽

The Arctic ◽

The North ◽

Stratospheric Temperature ◽

Climate Model Simulations ◽

Sst Anomalies

Five 50-year simulations with version 5 of the INM RAS coupled climate model revealed that the winters with El Nio are characterized by higher Arctic stratospheric temperature as compared to the seasons with La Nia. Lower stratospheric temperature in the Arctic regions as compared to the seasons with negative sea surface temperature (SST) anomalies corresponds to the winter seasons with positive SST anomalies in the North Pacific.

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Seasonal and Long-Term Coupling between Wintertime Storm Tracks and Sea Surface Temperature in the North Pacific

Journal of Climate ◽

10.1175/jcli-d-12-00724.1 ◽

2013 ◽

Vol 26 (16) ◽

pp. 6123-6136 ◽

Cited By ~ 26

Author(s):

Bolan Gan ◽

Lixin Wu

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

North Pacific ◽

Storm Track ◽

Sea Surface ◽

Storm Tracks ◽

The North ◽

The North Pacific ◽

Sst Anomalies

Abstract In this study, a lagged maximum covariance analysis (MCA) of the wintertime storm-track and sea surface temperature (SST) anomalies derived from the reanalysis datasets shows significant seasonal and long-term relationships between storm tracks and SST variations in the North Pacific. At seasonal time scales, it is found that the midlatitude warm (cold) SST anomalies in the preceding fall, which are expected to change the tropospheric baroclinicity, can significantly reduce (enhance) the storm-track activities in early winter. The storm-track response pattern, however, is in sharp contrast to the forcing pattern, with warm (cold) SST anomalies in the western–central North Pacific corresponding to a poleward (equatorward) shift of storm tracks. At interannual-to-decadal time scales, it is found that the wintertime SST and storm-track anomalies are mutually reinforced up to 3 yr, which is characterized by PDO-like SST anomalies with warming in the western–central domain coupled with basin-scale positive storm-track anomalies extending along 50°N.

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Projected expansion of the subtropical biome and contraction of the temperate and equatorial upwelling biomes in the North Pacific under global warming

ICES Journal of Marine Science ◽

10.1093/icesjms/fsq198 ◽

2011 ◽

Vol 68 (6) ◽

pp. 986-995 ◽

Cited By ~ 103

Author(s):

Jeffrey J. Polovina ◽

John P. Dunne ◽

Phoebe A. Woodworth ◽

Evan A. Howell

Keyword(s):

Global Warming ◽

Primary Production ◽

North Pacific ◽

Climate Model ◽

North Pacific Ocean ◽

Central Pacific ◽

The North ◽

Fish Catch ◽

Equatorial Upwelling ◽

The North Pacific

Abstract Polovina, J. J., Dunne, J. P., Woodworth, P. A., and Howell, E. A. 2011. Projected expansion of the subtropical biome and contraction of the temperate and equatorial upwelling biomes in the North Pacific under global warming. – ICES Journal of Marine Science, 68: 986–995. A climate model that includes a coupled ocean biogeochemistry model is used to define large oceanic biomes in the North Pacific Ocean and describe their changes over the 21st century in response to the IPCC Special Report on Emission Scenario A2 future atmospheric CO2 emissions scenario. Driven by enhanced stratification and a northward shift in the mid-latitude westerlies under climate change, model projections demonstrated that between 2000 and 2100, the area of the subtropical biome expands by ∼30% by 2100, whereas the area of temperate and equatorial upwelling (EU) biomes decreases by ∼34 and 28%, respectively, by 2100. Over the century, the total biome primary production and fish catch is projected to increase by 26% in the subtropical biome and decrease by 38 and 15% in the temperate and the equatorial biomes, respectively. Although the primary production per unit area declines slightly in the subtropical and the temperate biomes, it increases 17% in the EU biome. Two areas where the subtropical biome boundary exhibits the greatest movement is in the northeast Pacific, where it moves northwards by as much as 1000 km per 100 years and at the equator in the central Pacific, where it moves eastwards by 2000 km per 100 years. Lastly, by the end of the century, there are projected to be more than 25 million km2 of water with a mean sea surface temperature of 31°C in the subtropical and EU biomes, representing a new thermal habitat. The projected trends in biome carrying capacity and fish catch suggest resource managers might have to address long-term trends in fishing capacity and quota levels.

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