Relationship between the zonal displacement of the western Pacific subtropical high and the dominant modes of low-tropospheric circulation in summer

Lu, Riyu; Li, Ying; Ryu, Chan-Su

doi:10.1016/j.pnsc.2007.07.009

Cited by 50 publications

(17 citation statements)

References 14 publications

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“…Following Lu et al [2008], the GPH at 850 hPa is adopted to describe the WNPSH characteristics. Figure 2a shows the isopleth of 1500 m (solid contours) and the ridge line (dashed lines) of WNPSH in observation (black), SP-CCSM4 (red), and CCSM4 (blue).…”

Section: Seasonal Mean Of Easmmentioning

confidence: 99%

Simulation of East Asian Summer Monsoon (EASM) in SP‐CCSM4: Part I—Seasonal mean state and intraseasonal variability

Yan

Stan

2016

JGR Atmospheres

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The mean state and intraseasonal variability of the East Asian Summer Monsoon (EASM) simulated by the Super‐Parameterized Community Climate System Model version 4 (SP‐CCSM4) and the conventionally parameterized CCSM4 are evaluated against observations. The SP‐CCSM4 model has a better simulation of the May‐June‐July‐August seasonal mean state of EASM than CCSM4, although it produces a dry bias over the EASM area compared to observations. The dry bias in SP‐CCSM4 is associated with the erroneous northward displacement of the western North Pacific subtropical high. The SP‐CCSM4 model simulates the reasonable monsoon onset and northward propagation of the monsoonal precipitation, yet the rainband marches faster and reaches to a higher latitude than in observations. The mechanisms associated with the northward propagation of the intraseasonal oscillation (ISO) of EASM are also captured by SP‐CCSM4. The cyclonic vorticity and the moisture convergence lead the convective activity, favoring the northward propagation of convection. The easterly wind shear and air‐sea interaction mechanisms in the model are realistic and show contributions to the northward propagation of the ISO of the model. The SP‐CCSM4 model captures many facets of the stepwise northward propagation of the precipitation belt in the EASM region, including the Mei‐yu season. However, compared to the observations, in the model the onset of the Mei‐yu season takes place 5 days earlier and the duration of the Mei‐yu's rainy episode is shorter. The CCSM4 model has large deficiencies in simulating the intraseasonal variability of EASM.

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Section: Seasonal Mean Of Easmmentioning

confidence: 99%

Simulation of East Asian Summer Monsoon (EASM) in SP‐CCSM4: Part I—Seasonal mean state and intraseasonal variability

Yan

Stan

2016

JGR Atmospheres

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“…The eddy geopotential height is used instead of the traditional geopotential height to measure the WNPSH (Huang and Li 2015;He et al , 2018, which is because the traditional geopotential height systematically increases with increasing temperature (Lu, Li, and Ryu 2008) and more than 80% of its increase is attributable to zonally uniform warming (He et al 2018). The eddy geopotential height at 500 hPa (referred to as H′500 hereafter) is calculated by subtracting the zonal belt mean height between 0°and 40°N from the geopotential height (He et al 2018).…”

Section: Methodsmentioning

confidence: 99%

“…The eddy geopotential height at 500 hPa (referred to as H′500 hereafter) is calculated by subtracting the zonal belt mean height between 0°and 40°N from the geopotential height (He et al 2018). The WNPSH is also depicted by the geopotential height at 850 hPa (Lu 2002;Lu, Li, and Ryu 2008;Fu 2013). The eddy geopotential height at 850 hPa (referred to as H′850 hereafter) is calculated by subtracting the zonal mean height from the geopotential height (Huang, Li, and Wang 2016).…”

Section: Methodsmentioning

confidence: 99%

“…Additionally, the area-averaged eddy streamfunction over (10°-30°N, 120°-180°E) at 500 hPa is defined as the ESF500 index, following . At 850 hPa, the summer mean relative vorticity anomalies averaged over (15°-27.5°N, 125°-150°E) is defined as RV850, following Lu, Li, and Ryu (2008); the difference in the zonal wind between (25°-35°N, 120°-150°E) and (10°-20°N, 130°-150°E) is defined as Ua850, following .…”

Section: Methodsmentioning

confidence: 99%

“…Its intensity, shape, and location consequently have a large influence on the East Asian summer precipitation (Lu 2002;Ren, Yang, and Sun 2013). An anomalous WNPSH causes widespread disasters over East Asia, such as floods, drought and heat waves (Lu, Li, and Ryu 2008;Wang, Xiang, and Lee 2013). Thus, the future behavior of the summer WNPSH under global warming is of great concern.…”

Section: Introductionmentioning

confidence: 99%

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Projected changes in the western North Pacific subtropical high under six global warming targets

Guo

2019

Atmospheric and Oceanic Science Letters

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The summer western North Pacific subtropical high (WNPSH) has large influences on the East Asian summer climate. Many studies have focused on the projected changes in the WNPSH, but little is known about the changes under different global warming targets, such as 1.5°C and 2.0°C. This study investigates the changes in the WNPSH under six global warming targets (1.5°C, 2.0°C, 2.5°C, 3.0°C, 3.5°C, and 4.0°C) in both the mid-and lower troposphere, using the outputs of CMIP5 model in historical simulations and under Representative Concentration Pathway 8.5. The projected changes in the WNPSH, which is measured by multiple variables, show that it changes little under the 1.5°C target in the mid-troposphere, but weakens and retreats approximately 2.5°in longitude under the 2.0°C target. It tends to linearly weaken with warming greater than 2.5°C and shifts eastward by approximately 6.0°in longitude by the 4.0°C target. Meanwhile, the WNPSH intensifies and extends westward under the 1.5°C target in the lower troposphere, but changes little with warming rising from 1.5°C to 2.0°C. It is projected to extend westward by approximately 2.0°in longitude by the 4.0°C target.

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Summer extreme precipitation in eastern China: Mechanisms and impacts

et al. 2017

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With the highest population density in China, eastern China has an unshakable position in Chinese socioeconomic development. To understand the precipitation changes and the related mechanisms is of great significance for regional management of water resources and agricultural irrigation. In this study, the impacts of western North Pacific subtropical high (WNPSH) on precipitation changes in eastern China and the underlying processes are investigated. The results indicate that the strength and location of WNPSH are in close relations with the changes of summer precipitation in eastern China, and their influences vary across both space and time. In particular, WNPSH exerts remarkable impacts on precipitation in June and July in Jiang‐Huai region and precipitation in June in South China such as the Pearl River basin. The interannual variations of WNPSH exhibit significant correlations with water vapor flux in East Asia, and the variations of the location and direction of the west flank of the WNPSH are well corroborated with the influences of the East Asian summer monsoon (EASM) on precipitation in eastern China. The westward extension of WNPSH tends to favor the strong moisture transport to East Asia, intensify the EASM, and thus increase water vapor flux in East Asia, which greatly benefits the occurrence of Meiyu regimes in Jiang‐Huai region. Besides, analysis results also show that the westward extension of WNPSH drives tropical cyclones southward so as to increase the occurrence of extreme precipitation in South China. This study helps to bridge the knowledge gap in the relationship between WNPSH, tropical cyclones, and summer precipitation events in eastern China.

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Relationship between the zonal displacement of the western Pacific subtropical high and the dominant modes of low-tropospheric circulation in summer

Cited by 50 publications

References 14 publications

Simulation of East Asian Summer Monsoon (EASM) in SP‐CCSM4: Part I—Seasonal mean state and intraseasonal variability

Simulation of East Asian Summer Monsoon (EASM) in SP‐CCSM4: Part I—Seasonal mean state and intraseasonal variability

Projected changes in the western North Pacific subtropical high under six global warming targets

Summer extreme precipitation in eastern China: Mechanisms and impacts

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