Centennial-scale East Asian summer monsoon intensity based on δ18O values in ostracode shells and its relationship to land-ocean air temperature gradients over the past 1700 years

Geology ◽  
2016 ◽  
Vol 44 (4) ◽  
pp. 255-258 ◽  
Author(s):  
Katsura Yamada ◽  
Tetsuro Masuma ◽  
Saburo Sakai ◽  
Koji Seto ◽  
Hiroki Ogusa ◽  
...  
2018 ◽  
Vol 45 (15) ◽  
pp. 7711-7718 ◽  
Author(s):  
Richard Ching Wa Cheung ◽  
Moriaki Yasuhara ◽  
Briony Mamo ◽  
Kota Katsuki ◽  
Koji Seto ◽  
...  

2009 ◽  
Vol 28 (3-4) ◽  
pp. 345-353 ◽  
Author(s):  
Weiguo Zhang ◽  
Lizhong Yu ◽  
Min Lu ◽  
Xiangmin Zheng ◽  
Junfeng Ji ◽  
...  

2010 ◽  
Vol 23 (24) ◽  
pp. 6696-6705 ◽  
Author(s):  
Jianping Li ◽  
Zhiwei Wu ◽  
Zhihong Jiang ◽  
Jinhai He

Abstract The Indian summer monsoon (ISM) tends to be intensified in a global-warming scenario, with a weakened linkage with El Niño–Southern Oscillation (ENSO), but how the East Asian summer monsoon (EASM) responds is still an open question. This study investigates the responses of the EASM from observations, theoretical, and modeling perspectives. Observational and theoretical evidence demonstrates that, in contrast to the dramatic global-warming trend within the past 50 years, the regional-mean EASM rainfall is basically dominated by considerable interannual-to-decadal fluctuations, concurrent with enhanced precipitation over the middle and lower reaches of the Yangtze River and over southern Japan and suppressed rainfall amount over the South China and Philippine Seas. From 1958 through 2008, the EASM circulation exhibits a southward shift in its major components (the subtropical westerly jet stream, the western Pacific Ocean subtropical high, the subtropical mei-yu–baiu–changma front, and the tropical monsoon trough). Such a southward shift is very likely or in part due to the meridional asymmetric warming with the most prominent surface warming in the midhigh latitudes (45°–60°N), which induces a weakened meridional thermal contrast over eastern Asia. Another notable feature is the enhanced ENSO–EASM relationship within the past 50 years, which is opposite to the ISM. Fourteen state-of-the-art coupled models from the Intergovernmental Panel on Climate Change show that the EASM strength does not respond with any pronounced trend to the global-warming “A1B” forcing scenario (with an atmospheric CO2 concentration of 720 ppm) but shows interannual-to-decadal variations in the twenty-first century (2000–99). These results indicate that the primary response of the EASM to a warming climate may be a position change instead of an intensity change, and such position change may lead to spatial coexistence of floods and droughts over eastern Asia as has been observed in the past 50 years.


2012 ◽  
Vol 8 (4) ◽  
pp. 3251-3276 ◽  
Author(s):  
W. Zheng ◽  
B. Wu ◽  
J. He ◽  
Y. Yu

Abstract. Ten Coupled General Circulation Models (CGCMs) participating the third phase of Paleoclimate Modeling Intercomparison project (PMIP3) are assessed for the simulations of East Asian Summer Monsoon (EASM) at both the present climate and mid-Holocene. Results show that the PMIP3 model median well captures the characteristics of the EASM, including the two distinct features of the Meiyu Front and the stepwise meridional displacement of the monsoon rainbelt. At mid-Holocene, the enhanced EASM is simulated by the PMIP3 models. The model median shows that the changes of surface air temperature and precipitation are within the range as indicated by the proxy data over the eastern China. Both the changes of monsoonal circulation and the water vapor content favor the increasing of summer precipitation. Regional features can be identified between models because of their different simulations of the above changes. The model spread for the surface air temperature (TAS) is relatively smaller when compared with that of PMIP2 models in both the Northern Hemisphere and the eastern China. However, the model spread of summer precipitation is larger among PMIP3 models, particularly in the lower reaches of Yangzi River. The TAS over Tibetan Plateau has a positive relationship with the precipitation in the lower reaches of Yangzi River, yet this relationship does not apply for those PMIP3 models in which the monsoonal precipitation is more sensitive to the changes of large-scale circulation.


2015 ◽  
Vol 28 (7) ◽  
pp. 2873-2883 ◽  
Author(s):  
Shinji Matsumura ◽  
Shiori Sugimoto ◽  
Tomonori Sato

Abstract The summer western Pacific subtropical high (WPSH) has intensified during the past three decades. However, the underlying mechanism is not yet well understood. Here, it is shown that baiu rainband activity in midsummer, which is part of the East Asian summer monsoon, plays an important role in recent intensification in the WPSH along the baiu rainband. In contrast with the WPSH, the summer Okhotsk high, which is located to the north of the baiu rainband, has weakened during the past three decades. The north–south contrasting changes between the two highs reflect a response to northward-moved and enhanced baiu heating, which intensifies the upper-tropospheric ridge, resulting in the baroclinic intensification of the WPSH. Regional climate model experiments also support the observational analysis. Therefore, baiu convective activity in midsummer can act as a major driver for the WPSH intensification. The results here suggest that the mechanism intensifying the summer North Pacific subtropical high clearly differs between the western and eastern Pacific.


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