2022-12-17 14:20:46


Progress of Projects Supported by NSFC

September 2012 Vol.57 No.27: 35353540

Atmospheric Science doi: 10.1007/s11434-012-5285-x

Weakening relationship between East Asian winter monsoon and ENSO after mid-1970s

WANG HuiJun1,2* amp; HE ShengPing1,2,3

  1. Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China;
  2. Climate Change Research Center, Chinese Academy of Sciences, Beijing 100029, China;
  3. Graduate University of Chinese Academy of Sciences, Beijing 100049, China

Received February 20, 2012; accepted April 24, 2012; published online June 17, 2012

The East Asian winter monsoon (EAWM) is characterized by the frequent cold surges and associated closely with the Siberia

High, East Asian Trough, and high-level westerly jet stream. The ENSO cycle can modulate the EAWM since it has co-variability

with the sea surface temperature over the Indo-Western-Pacific which can tune the land-sea thermal contrast for the EAWM. This

paper, by analyzing the EAWM, ENSO, and associated atmosphere-ocean variability, documents the weakening of the EAWM-

ENSO relationship after the 1970s. The significant out-of-phase inter-relationship is found to be diminished after the 1970s. Further

study in this work suggests that the weakened co-variability of the tropical Indo-Western-Pacific climate associated with ENSO

after the 1970s is partly responsible for the weakened inter-relationship. Meanwhile, the reduced EAWM interannual variability

and northward retreat of the EAWM-associated climate variability are favorable to the weakened ENSO-EAWM connection.

East Asian winter monsoon, ENSO, interdecadal variability, interannual variability

Citation: Wang H J, He S P. Weakening relationship between East Asian winter monsoon and ENSO after mid-1970s. Chin Sci Bull, 2012, 57: 35353540, doi:


The East Asian winter monsoon (EAWM) is characterized by the frequent cold surges in the lower atmosphere and has broad impact on the climate of Asia and tropical Indo-Pacific [1]. The EAWM is closely associated with the Siberia High in low atmosphere, the East Asian Trough in middle tropo- sphere, and the westerly jet stream in high troposphere. In the past years, there has been increased disasters in China resulted by anomalous East Asian winter monsoon and as- sociated snowstorms [2–4].

There is remarkable interannual and interdecadal varia-

bility of EAWM [5–9]. The out-of-phase relationship be- tween ENSO and EAWM variation was documented by Webster and Yang [10], Zhang et al. [11], and Lau and Nath [12]. Gong et al. [13] indicated the connection between var- iability of the Arctic Oscillation and EAWM. Thus the EAWM is mainly regulated by the ENSO cycle and the

*Corresponding author (email: wanghj@mail.iap.ac.cn)

Arctic Oscillation in the interannual variability. Recently, Liu et al. [14] indicated that the Arctic sea ice content has substantial impact on the EAWM, winter temperature and snowstorm activity.

However, both the EAWM and ENSO have the decadal

and interdecadal fluctuations, accompanied by complex vari- ation of the climate regimes [15–17]. The inter-relationship between the East Asian summer monsoon and ENSO is not stable from decades to decades [18]. The instable linkage of the summer monsoon to ENSO leads to low ENSO-induced climate predictability in East Asia. Thus the long-term vari- ation of the EAWM-ENSO connection is important, but has not been well recognized so far.

In this paper, we will first verify the moving correlation

coefficient between the EAWM and ENSO index and then analyze the associated atmospheric and oceanic climate variability in the two typical periods with high and low inter- relationships respectively. Since our concern in this paper is

copy; The Author(s) 2012. This article is published with open access at Springerlink.com csb.scichina.com www.springer.com/scp

3536 Wang H J, et al. Chin Sci Bull September (2012) Vol.57 No.27

the inter-decadal variability, we adopted 23-years sliding window for analyzing the moving correlation.

The data sets employed in this research include the Na-

tional Centers for Environmental Prediction (NCEP) 2.5°times;

2.5° resolution reanalysis for 1948–2010 [19], and the sea surface temperature (SST) data with 2.0°times;2.0° resolution from the National Oceanic and Atmospheric Administration (NOAA) [20]. The East Asian winter monsoon index (EAWMI) is defined as the mean geopotential height at 500 hPa in the area of(25°–45°N, 110°–145°E)to describe the

East Asian trough that closely associated with the EAWM and cold surge activity. Since the Aleutian low pressure system is a dominant mode in North Pacific, we will also

investigate its relationship to ENSO. The sea-level pressure

averaged in the region of (155°E–130°W, 30°–70°N) is defined as the index of Aleutian Low (ALI). In this paper, the December-January-February (DJF) mean is taken to stand for the boreal winter. The Nintilde;o3.4 index is computed as the mean SST in the tropical eastern Pacific (170°– 120°W, 5°N–5°S) to describe the phase of ENSO.

  1. The weakening relationship between EAWM

and ENSO after the 1970s

We first plotted the temporal variation of the EAWMI and Nintilde;o3.4 in Figure 1. Clearly, the EAWM becomes much weakened after mid-1980s. Meanwhile the interannual

Figure 1 The interannual variation of the DJF mean EAWMI (a) and Nintilde;o3.4 SSTA index (b) during 1948–2010.

Wang H J, et al. Chin Sci Bull September (2012) Vol.57 No.27 3537

variability is also reduce



国家自然科学基金资助项目进展情况 2012年9月Vol.57 No.27:35353540

大气科学 doi:10.1007 / s11434-012-5285-x






2012年2月20日收到; 2012年4月24日接受; 2012年6月17日在线发表

东亚冬季风(EAWM)的特点是频繁的寒潮,并与西伯利亚高压,东亚大槽和高层西风急流密切相关。 ENSO循环可以调节EAWM,因为它与印度-西太平洋的海温具有共变性,而海温可以调节EAWM海陆热力差异。本文通过分析EAWM,ENSO和相关的海气变率,发现20世纪70年代后EAWM和ENSO关系的减弱。在20世纪70年代之后,显著反相关减弱。 对这项工作的进一步研究表明,20世纪70年代后与ENSO相关的热带印度 - 西太平洋气候的共同变化减弱是造成相互关系减弱的部分原因。 同时,减弱的EAWM年际变率和EAWM耦合的气候变率的向北撤退有利于ENSO-EAWM关系的减弱。


东亚冬季风(EAWM)的特点是低层大气频繁的寒潮,对亚洲和热带印度洋-太平洋的气候影响很大[1]。 EAWM与西伯利亚高压,东亚大槽以及西风急流密切相关。在过去几年中,中国由于东亚冬季风异常和相关的暴风雪引起的灾害在加剧。 [2-4]。

EAWM存在显着的年际变化和年代际变化[5-9]。 EN和EAWM变异之间的异相关系由Webster和Yang [10],Zhang等人记录。 [11],Lau和Nath [12]。Gong等人 [13]表明北极涛动与EAWM的可变性之间存在联系。 因此,EAWM主要受ENSO循环和



然而,EAWM和ENSO都有年际和年代际变化,并伴随着气候的复杂变化[15-17]。 东亚夏季风与ENSO之间的相互关系时而稳定时而不稳定[18]。 夏季风与ENSO的不稳定联系导致东亚地区ENSO引起的气候可预测性较低。因此,EAWM-ENSO连接的长期变化很重要,但到目前为止还没有得到很好的认可。



本研究中使用的数据集包括国家环境预测中心(NCEP)1948-2010的2.5°times;2.5°分辨率再分析资料[19],以及国家海洋和大气管理局(NOAA)的2.0°times;2.0°分辨率的海面温度(SST)数据 [20]。 东亚冬季风指数(EAWMI)定义为500 hPa(25°-45°N,110°-145°E)区域的平均位势高度,用于描述与EAWM密切相关的东亚大槽和寒潮活动。 由于阿留申低压系统是北太平洋的主导系统,我们还将研究其与ENSO的关系。 (155°E-130°W,30°-70°N)区域的海平面气压的平均值被定义为阿留申低压指数(ALI)。 在本文中,12月-1月-2月(DJF)的意思是代表冬季。 Nintilde;o3.4指数计算为热带东太平洋(170° - 120°W,5°N-5°S)的平均海温以描述ENSO的相位。


我们首先绘制了图1中EAWMI和Nintilde;o3.4的时间演变曲线。显然,EAWM在20世纪80年代中期后显著变弱。 同时年代际

1 东亚冬季风指数 EAWMI(a)和 Nintilde;o3.4 指数(b)的年际变化(1948~2010 年)

变率在后期也削弱了。相比之下,Nintilde;o3.4在平均强度和年际变率方面没有显著的长期变化。然后我们计算了1948 - 2010年间EAWMI(ALI)和Nintilde;o3.4之间23年滑动窗口的滑动相关系数。 图2表明Nintilde;o3.4与

EAWMI的反相关系在20世纪70年代中期之前非常显著,但之后并不明显。 相反,Nintilde;o3.4与ALI之间的异相关系经历了一个相反的过程,从无关紧要到显著相关。


图 2 Nintilde;o3.4 指数和 EAWMI(a)以及 ALI(b)在 1948~2010年间的 23 a 滑动相关系数

横虚线表示达到 95%信度的水平(t 检验)

图 3 1948~1976 年(a)和 1977~2010 年(b)时段 Nintilde;o3.4 指数和 850 hPa 经向风的年际变化相关系数空间分布

阴影区为达到 95%以上信度的水平(t 检验)的区域

在20世纪70年代中期后有向南移和向东移的趋势。因此,我们通过分析两个时期1948-1976(P1)和1977-2010(P2)的850 hPa经向风和Nintilde;o3.4指数之间的相关系数来测试这种ENSO影响的移动。我们确实发现ENSO信号位于西北太平洋和东北亚地区时,P1和P2之间存在差异。 在P1期间,Nintilde;o3.4的正相对应于南海,我国东部和东北亚(弱东亚冬季风)的经向风的正异常,以及勘察加半岛地区和北部热带东太平洋的经向风负异常,反之亦然。 在后期(P2),亚洲的正相关区退回到我国南海和东南亚地区。我国东部和日韩地区没有显著的相关性。与此同时,堪萨斯半岛的负相关区域向东南方向撤退到了阿留申及北太平洋中纬度地区。因此,P2中的Nintilde;o3.4-ALI反相关关系增强。值得注意的是,北美的ENSO信号在P1和P2之间也有所不同。


图4 1948-1976(a)和1977-2010(b)期间Nintilde;o3.4 指数和表面 2 m 高处气温的年际变化相关系数空间分布

阴影区为达到 95%以上信度的水平(t 检验)的区域

为什么EAWM-Nintilde;o3.4指数关系在20世纪70年代中期后变弱了?我们现在通过EOF(经验正交函数)分解SST。图5表明比起P1时期,P2时期的热带东太平洋海温与热带印度-西太平洋海温的关系减弱了。我们发现EOF1在印度太平洋90°-150°E区域(ENSO模式)的正值在P1中比在P2中在数量上更大并且在空间上更宽。 此部分的海温异常与EAWM密切相关,因为它们可以调节作为EAWM基本驱动力的海陆热力差异。


图 5 冬季海表温度在 1948~1976 年和 1977~2010 年两个时段的 EOF 分解的前两个主分量的空间分布

图 6 同图 3, 但为 EAWMI 和 2 m 高处气温的年际变化相关系数空间分布


本文揭示了20世纪70年代中期以后EAWM与ENSO循环之间的关系减弱。它们之间的联系在1948年至1976年期间显著相关,并且在1977年至2010年期间无关紧要。我们发现,与印度洋北部,亚洲和西太平洋地区的东亚冬季气候相关的Nintilde;o3.4基本上向南退回到低纬度地区。 在亚太北部,ENSO信号在20世纪70年代中期后从东北亚向东移动到西北太平洋,导致P2中的ENSO-阿留申低压联系加强。


This work was supported by the National Natural Science Foundation of China (41130103) and the National Basic Research Program of China (2009CB421406). Thanks are due to Dr. Jianqi Sun for his helpful com- ments.

  1. Tao S Y, Chen L X. A review of recent research of the East Asian

summer monsoon in China. Monsoon Meteorology. Oxford: Oxford University Press, 1985. 60–92

  1. Wang H J, Yu E T, Yang S. An exceptionally heavy snowfall in

Northeast China: Large-scale circulation anomalies and hindcast of the NCAR WRF model. Meteorol Atmos Phys, 2011, 113: 11–25

  1. Sun J Q, Wang H J, Yuan W. A preliminary investigation on causes

of the catastrophic snowstorm in March, 2007 in the northeastern

parts of China (in Chinese). Acta Meteorol Sin, 2009, 67: 469–477

4 Sun J Q, Wang H J, Yuan W, et al. Spatial-temporal features of

intense snowfall events in China and their possible change. J Geophys Res, 2010, 115: D16110

  1. Ji L R, Sun S Q, Arpe K, et al. Model study on the interannual varia-

bility of Asian winter monsoon and its influence. Adv Atmos Sci, 1997, 14: 1–22

  1. Zhang Y, Sperber K R, Boyle J S. Climatology and interannual varia-

tion of the East Asian winter monsoon: Results from the 1979–95 NCEP/NCAR reanalysis. Mon Weather Rev, 1997, 125: 2605–2619

  1. Wang H J. The weakening of the Asian monsoon circulation after the

end of 1970rsquo;s. Adv Atmos Sci, 2001, 18: 376–386

  1. Jhun J G, Lee E J. A new East Asian winter monsoon index and asso-

ciated characteristics of the winter monsoon. J Clim, 2004, 17: 711–


  1. Zhu C W, Lee W S, Kang H W, et al. A proper monsoon index for

seasonal and interannual variations of the East Asian monsoon. Ge- ophys Res L



您需要先支付 30元 才能查看全部内容!立即支付