Limits...
Enhanced or Weakened Western North Pacific Subtropical High under Global Warming?

He C, Zhou T, Lin A, Wu B, Gu D, Li C, Zheng B - Sci Rep (2015)

Bottom Line: The potential change of the WNPSH under global warming is concerned by Asian people, but whether the WNPSH would be enhanced or weakened remains inconclusive.Weakened meridional temperature gradient on the northern flank of WNPSH and the associated thermal wind account for the weakened WNPSH in the mid troposphere.We recommend the WNPSH be measured by eddy geopotential height (He) instead of traditionally used geopotential height, especially in climate change studies.

View Article: PubMed Central - PubMed

Affiliation: Institute of Tropical and Marine Meteorology (ITMM), China Meteorological Administration (CMA), Guangzhou, China.

ABSTRACT
The Western North Pacific Subtropical High (WNPSH) regulates East Asian climate in summer. Anomalous WNPSH causes floods, droughts and heat waves in China, Japan and Korea. The potential change of the WNPSH under global warming is concerned by Asian people, but whether the WNPSH would be enhanced or weakened remains inconclusive. Based on the multi-model climate change projection from the 5th phase of Coupled Model Intercomparison Project (CMIP5), we show evidences that the WNPSH tends to weaken and retreat eastward in the mid-troposphere in response to global warming, accompanied by an eastward expansion of East Asian rain belt along the northwestern flank of WNPSH. Weakened meridional temperature gradient on the northern flank of WNPSH and the associated thermal wind account for the weakened WNPSH in the mid troposphere. We recommend the WNPSH be measured by eddy geopotential height (He) instead of traditionally used geopotential height, especially in climate change studies.

No MeSH data available.


Related in: MedlinePlus

The seasonal mean state of WNPSH for June-July-August at 500 hPa.(a) The observation. (b) Historical run. (c) RCP8.5 run. The shading is geopotential height (“H”, unit: m), and the vectors are winds (unit:m s−1). The solid line is the 0 m contour of eddy geopotential height (He = 0 m), and the dashed line is the 0 m2 s−1 contour of eddy stream function (Se = 0 m2 s−1). The regions with a precipitation rate above 5 mm·day−1 north of 25˚N are filled with blue dots. This plot was created by NCAR Command Language36.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4660429&req=5

f1: The seasonal mean state of WNPSH for June-July-August at 500 hPa.(a) The observation. (b) Historical run. (c) RCP8.5 run. The shading is geopotential height (“H”, unit: m), and the vectors are winds (unit:m s−1). The solid line is the 0 m contour of eddy geopotential height (He = 0 m), and the dashed line is the 0 m2 s−1 contour of eddy stream function (Se = 0 m2 s−1). The regions with a precipitation rate above 5 mm·day−1 north of 25˚N are filled with blue dots. This plot was created by NCAR Command Language36.

Mentions: The WNPSH is usually measured by geopotential height (H) over the WNP. Higher (lower) H over WNP is regarded as a stronger (weaker) WNPSH. The 5880 m contour of H at 500 hPa is widely used as a benchmark to measure the WNPSH by meteorologists from China, Korea and Japan11720 to determine the location of heavy rains, because East Asian rain belt is usually located on the northwest of this contour1517 (Fig. 1a).


Enhanced or Weakened Western North Pacific Subtropical High under Global Warming?

He C, Zhou T, Lin A, Wu B, Gu D, Li C, Zheng B - Sci Rep (2015)

The seasonal mean state of WNPSH for June-July-August at 500 hPa.(a) The observation. (b) Historical run. (c) RCP8.5 run. The shading is geopotential height (“H”, unit: m), and the vectors are winds (unit:m s−1). The solid line is the 0 m contour of eddy geopotential height (He = 0 m), and the dashed line is the 0 m2 s−1 contour of eddy stream function (Se = 0 m2 s−1). The regions with a precipitation rate above 5 mm·day−1 north of 25˚N are filled with blue dots. This plot was created by NCAR Command Language36.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660429&req=5

f1: The seasonal mean state of WNPSH for June-July-August at 500 hPa.(a) The observation. (b) Historical run. (c) RCP8.5 run. The shading is geopotential height (“H”, unit: m), and the vectors are winds (unit:m s−1). The solid line is the 0 m contour of eddy geopotential height (He = 0 m), and the dashed line is the 0 m2 s−1 contour of eddy stream function (Se = 0 m2 s−1). The regions with a precipitation rate above 5 mm·day−1 north of 25˚N are filled with blue dots. This plot was created by NCAR Command Language36.
Mentions: The WNPSH is usually measured by geopotential height (H) over the WNP. Higher (lower) H over WNP is regarded as a stronger (weaker) WNPSH. The 5880 m contour of H at 500 hPa is widely used as a benchmark to measure the WNPSH by meteorologists from China, Korea and Japan11720 to determine the location of heavy rains, because East Asian rain belt is usually located on the northwest of this contour1517 (Fig. 1a).

Bottom Line: The potential change of the WNPSH under global warming is concerned by Asian people, but whether the WNPSH would be enhanced or weakened remains inconclusive.Weakened meridional temperature gradient on the northern flank of WNPSH and the associated thermal wind account for the weakened WNPSH in the mid troposphere.We recommend the WNPSH be measured by eddy geopotential height (He) instead of traditionally used geopotential height, especially in climate change studies.

View Article: PubMed Central - PubMed

Affiliation: Institute of Tropical and Marine Meteorology (ITMM), China Meteorological Administration (CMA), Guangzhou, China.

ABSTRACT
The Western North Pacific Subtropical High (WNPSH) regulates East Asian climate in summer. Anomalous WNPSH causes floods, droughts and heat waves in China, Japan and Korea. The potential change of the WNPSH under global warming is concerned by Asian people, but whether the WNPSH would be enhanced or weakened remains inconclusive. Based on the multi-model climate change projection from the 5th phase of Coupled Model Intercomparison Project (CMIP5), we show evidences that the WNPSH tends to weaken and retreat eastward in the mid-troposphere in response to global warming, accompanied by an eastward expansion of East Asian rain belt along the northwestern flank of WNPSH. Weakened meridional temperature gradient on the northern flank of WNPSH and the associated thermal wind account for the weakened WNPSH in the mid troposphere. We recommend the WNPSH be measured by eddy geopotential height (He) instead of traditionally used geopotential height, especially in climate change studies.

No MeSH data available.


Related in: MedlinePlus