scholarly journals Interannual teleconnections between the summer North Atlantic Oscillation and the East Asian summer monsoon

2011 ◽  
Vol 116 (D13) ◽  
Author(s):  
Hans W. Linderholm ◽  
Tinghai Ou ◽  
Jee-Hoon Jeong ◽  
Chris K. Folland ◽  
Daoyi Gong ◽  
...  
2019 ◽  
Author(s):  
Fucai Duan ◽  
Zhenqiu Zhang ◽  
Yi Wang ◽  
Jianshun Chen ◽  
Zebo Liao ◽  
...  

Abstract. Variations of East Asian summer monsoon (EASM) during the last millennium could help enlighten the monsoonal response to future global warming. Here we present a precisely dated and highly resolved stalagmite δ18O record from the Yongxing Cave, central China. Our new record, combined with a previously published one from the same cave, indicates that the EASM has changed dramatically in association with the global temperature rising. In particular, our record shows that the EASM has intensified during the Medieval Climate Anomaly (MCA) and the Current Warm Period (CWP) but weakened during the Little Ice Age (LIA). We find that the EASM intensity is similar during the MCA and CWP periods in both northern and central China, but relatively stronger during the CWP in southern China. This discrepancy indicates a complicated regional response of the EASM to the anthropogenic forcing. The intensified and weakened EASM during the MCA and LIA matches well with the warm and cold phases of Northern Hemisphere surface air temperature, respectively. This EASM pattern also corresponds well with the rainfall over the tropical Indo-Pacific warm pool. Surprisingly, our record shows a strong association with the North Atlantic climate as well. The intensified (weakened) EASM correlates well with positive (negative) phases of North Atlantic Oscillation. In addition, our record links well with the strong (weak) Atlantic meridional overturning circulation during the MCA (LIA) period. All above-mentioned correlations indicate that the EASM tightly couples with oceanic processes in the tropical Pacific and North Atlantic oceans during the MCA and LIA.


2013 ◽  
Vol 52 (5) ◽  
pp. 1127-1138 ◽  
Author(s):  
Doo Young Lee ◽  
Joong-Bae Ahn ◽  
Karumuri Ashok

AbstractThe authors propose the use of a “climate filter” concept to enhance prediction skill of a multimodel ensemble (MME) suite for the East Asian summer monsoon (EASM) precipitation and temperature at 850 hPa. The method envisages grading models on the basis of the degree of reproducibility of the association of EASM variability with a few relevant climate drivers with the respective model hindcasts for the period 1981–2003. The analysis identifies the previous winter Niño-3.4 and spring North Atlantic Oscillation indices as the most suitable climate drivers in designing a climate filter for evaluating models that replicate the observed teleconnections to EASM well. The results show that the hindcast skills of a new MME with the better-performing models are significantly higher than those from the nonperforming models or from an all-inclusive operational MME.


2016 ◽  
Vol 55 (7) ◽  
pp. 1459-1476 ◽  
Author(s):  
Fei Zheng ◽  
Jianping Li ◽  
Yanjie Li ◽  
Sen Zhao ◽  
Difei Deng

AbstractThe dominant mode of atmospheric circulation over the North Atlantic region is the North Atlantic Oscillation (NAO). The boreal spring NAO may imprint its signal on contemporaneous sea surface temperature (SST), leading to a North Atlantic SST tripolar pattern (NAST). This pattern persists into the following summer and modulates the East Asian summer monsoon (EASM). Previous studies have shown that the summer NAST is caused mainly by the preceding spring NAO, whereas the contemporaneous summer NAO plays a secondary role. The results of this study illustrate that, even if the summer NAO plays a secondary role, it may also perturb summer SST anomalies caused by the spring NAO. There are two types of perturbation caused by the summer NAO. If the spring and summer NAO patterns have the same (opposite) polarities, the summer NAST tends to be enhanced (reduced) by the summer NAO, and the correlation between the spring NAO and EASM is usually stronger (weaker). In the former (latter) case, the spring-NAO-based prediction of the EASM tends to have better (limited) skill. These results indicate that it is important to consider the evolution of the NAO when forecasting the EASM, particular when there is a clear reversal in the polarity of the NAO, because it may impair the spring-NAO-based EASM prediction.


2018 ◽  
Vol 14 (10) ◽  
pp. 1417-1425 ◽  
Author(s):  
Jule Xiao ◽  
Shengrui Zhang ◽  
Jiawei Fan ◽  
Ruilin Wen ◽  
Dayou Zhai ◽  
...  

Abstract. The 4.2 ka BP event has been widely investigated since it was suggested to be a possible cause for the collapse of ancient civilizations. With the growth of proxy records for decades, however, both its nature and its spatial pattern have become controversial. Here we examined multi-proxy data of the grain-size distribution, ostracode assemblage, pollen assemblage, and the pollen-reconstructed mean annual precipitation from a sediment core at Hulun Lake in northeastern Inner Mongolia spanning the period between 5000 and 3000 cal. yr BP to identify the nature and the associated mechanism of the 4.2 ka BP event occurring in the monsoonal region of eastern Asia. Higher sand fraction contents, littoral ostracode abundances, and Chenopodiaceae pollen percentages together with lower mean annual precipitation reveal a significant dry event at the interval of 4210–3840 cal. yr BP that could be a regional manifestation of the 4.2 ka BP event in the northern margin of the East Asian summer monsoon (EASM). We suggest that the drought would be caused by a decline in the intensity of the EASM on millennial-to-centennial scales that could be physically related to persistent cooling of surface waters in the western tropical Pacific and the North Atlantic. The cooling of western tropical Pacific surface waters could reduce moisture production over the source area of the EASM, while the cooling of North Atlantic surface waters could suppress northward migrations of the EASM rain belt, both leading to a weakened EASM and thus decreased rainfall in the northern margin of the EASM.


2018 ◽  
Author(s):  
Jule Xiao ◽  
Shengrui Zhang ◽  
Jiawei Fan ◽  
Ruilin Wen ◽  
Dayou Zhai ◽  
...  

Abstract. The 4.2 ka event has been widely investigated since it was suggested to be a possible cause for the collapse of ancient civilizations. With the growth of proxy records for decades, however, both its nature and its spatial pattern have become controversial. Here we examined multi-proxy data of the grain-size distribution, ostracode assemblage, pollen assemblage and the pollen-reconstructed mean annual precipitation from a sediment core at Hulun Lake in northeastern Inner Mongolia spanning the period between 5000 and 3000 cal yr BP to identify the nature and the associated mechanism of the 4.2 ka event occurring in the monsoonal region of eastern Asia. Higher sand fraction contents, littoral ostracodes abundances and Chenopodiaceae pollen percentages together with lower mean annual precipitations reveal a significant dry event at the interval of 4230–3820 cal yr BP that could be a regional manifestation of the 4.2 ka event in the northern margin of the East Asian summer monsoon (EASM). We suggest that the drought would be caused by a large decline in the intensity of the EASM on millennial-to-centennial scales that could be physically related to persistent cooling of surface waters in the western tropical Pacific and the North Atlantic. The cooling of western tropical Pacific surface waters could reduce moisture productions over the source area of the EASM, while the cooling of North Atlantic surface waters could suppress northward migrations of the EASM rainbelt, both leading to a weakened EASM and thus decreased rainfall in the northern margin of the EASM.


2021 ◽  
Vol 414 ◽  
pp. 125477
Author(s):  
Xiaohui Wang ◽  
Kai Liu ◽  
Lixin Zhu ◽  
Changjun Li ◽  
Zhangyu Song ◽  
...  

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