Abstract
In 2018, summer precipitation was above normal in North and Northwest China and below normal around the Yangtze River valley, due to an extremely strong East Asian summer monsoon (EASM). The atmospheric circulation anomalies in East Asia and key external forcing factors that influence the EASM in 2018 are explored in this paper. The results show that there existed an anomalous cyclonic circulation near the Philippines, while the western Pacific subtropical high was located more northward than its normal position. In the mid-high latitudes, a negative geo-potential height anomaly center was found near the Ural Mountains, suppressing the blocking activity. Under such a circulation pattern, precipitation near the Yangtze River valley decreased because local divergence and subsidence intensified, whereas precipitation in northern China increased due to large amounts of water vapor transport by anomalously strong southerly winds. Further analyses reveal that the strong EASM circulation in 2018 might result from the joint influences of several external forcing factors. The weak La Nina event that started from October 2017, the positive North Atlantic Tripolar mode (NAT) in spring 2018, and the reduced snow cover over the Tibetan Plateau in winter 2017/18 all collaboratively contributed to formation of the cyclonic circulation anomaly near the Philippines, leading to the extremely strong EASM. Especially, the positive NAT and the reduced Tibetan snow cover may have caused the negative geopotential height anomaly near the Ural Mountains, in favor of a strong EASM. The above external factors and their reinforcing impacts on the EASM are further verified by two groups of similar historical cases.
Similar content being viewed by others
References
Chen, L. J., Y. Yuan, M. Z. Yang, et al., 2013: A review of physical mechanisms of the global SSTA impact on the EASM. J. Appl. Meteor. Sci., 24, 521–532, doi: https://doi.org/10.3969/j.issn.l001-7313.2013.05.002. (in Chinese)
Chen, L. J., W. Gu, T. Ding, et al., 2016: Overview of the precursory signals of seasonal climate prediction in summer 2015. Meteor. Mon., 42, 496–506. (in Chinese)
Chen, L. J., W. Gu, Z. X. Gong, et al., 2019: Precursory signals of the 2018 summer climate in China and evaluation of the realtime prediction. Meteor. Mon., 45, 553–564. (in Chinese)
Chen, Q. J., B. Gao, W. J. Li, et al., 2000: Studies on relationships among abnormal winter snow cover over the Tibetan Plateau, Meiyu season droughts/floods in the middle-lower reaches of the Yangtze River, and atmospheric circulation patterns. Acta Meteor. Sinica, 58, 582–595, doi: https://doi.org/10.11676/qxxb2000.060. (in Chinese)
Chen, X. F., and Z. G. Zhao, 2000: Study on Precipitation Forecast in China During Flood Season and Associated Application. China Meteorological Press, Beijing, 241 pp. (in Chinese)
Feng, J., L. Wang, and W. Chen, 2014: How does the East Asian summer monsoon behave in the decaying phase of El Niño during different PDO phases? J. Climate, 27, 2682–2698, doi: https://doi.org/10.1175/JCLI-D-13-00015.1.
Feng, M., B. J. Wang, and S. Q. Xiong, 2000: Analysis on the abnormality of general circulation and sea temperature in relation to the flood water of Yangtze river in 1998. Resour. Environ. Yangtze Basin, 9, 112–117, doi: https://doi.org/10.3969/j.issn.1004-8227.2000.01.017. (in Chinese)
Gao, H., and Y. G. Wang, 2007: On the weakening relationship between summer precipitation in China and ENSO. Acta Meteor. Sinica, 65, 131–137, doi: https://doi.org/10.11676/qxxb2007.013. (in Chinese)
Gu, W., and L. J. Chen, 2019: Characteristics of atmospheric and oceanic conditions and their influence on summer climate of China in 2018. Meteor. Mon., 45, 126–134. (in Chinese)
Gu, W., C. Y. Li, X. Wang, et al., 2009: Linkage between Mei-yu precipitation and North Atlantic SST on the decadal times-cale. Adv. Atmos. Sci., 26, 101–108, doi: 10.1007ss00376-009-0101-5.
Guo, Y. J., W. Li, and Q. J. Chen, 2004: An operational monitoring and diagnosing system for snow cover in the Northern Hemisphere. Meteor. Mon., 30, 24–27, doi: https://doi.org/10.3969/j.issn.1000-0526.2004.11.005. (in Chinese)
He, J. H., X. F. Zhi, and T. Nakazawa, 1995: Seasonal interlock of the intraseasonal variations of rainfall in East China. J. Trop. Meteor., 11, 370–374, doi: https://doi.org/10.16032/j.issn.1004-4965.l995.04.010. (in Chinese)
Huang, R. H., 1992: The East Asia/Pacific pattern teleconnection of summer circulation and climate anomaly in East Asia. Acta Meteor. Sinica, 6, 25–37.
Huang, R. H., and W. J. Li, 1987: Influence of the heat source anomaly over the western tropical Pacific on the subtropical high over East Asia. Proc. International Conference on the General Circulation of East Asia, Chengdu, China, 40–51.
Huang, R. H., and Y. F. Wu, 1989: The influence of ENSO on the summer climate change in China and its mechanism. Adv. Atmos. Sci., 6, 21–32, doi: https://doi.org/10.1007/BF02656915.
Huang, R. H., W. Chen, Y. H. Ding, et al., 2003: Studies on the monsoon dynamics and the interaction between monsoon and ENSO cycle. Chinese J. Atmos. Sci., 27, 484–502, doi: https://doi.org/10.3878/j.issn.1006-9895.2003.04.05. (in Chinese)
Huang, R. H., J. L. Chen, L. Wang, et al., 2012: Characteristics, processes, and causes of the spatio-temporal variabilities of the East Asian monsoon system. Adv. Atmos. Sci., 29, 910–942, doi: https://doi.org/10.1007/s00376-012-2015-x.
Kalnay, E., M. Kanamitsu, R. Kistler, et al., 1996: The NCEP/NCAR 40-year reanalysis project. Bull. Amer. Meteor. Soc., 77, 437–472, doi: https://doi.org/10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2.
Kistler, R., E. Kalnay, W. Collins, et al., 2001: The NCEP-NCAR 50-year reanalysis: Monthly means CD-ROM and documentation. Bull. Amer. Meteor. Soc., 82, 247–268, doi: https://doi.org/10.1175/1520-0477(2001)082<0247:TNNYRM>2.3.CO;2.
Li, C. Y., R. H. Huang, J. F. Chou, et al., 2009: The Study of Meteorological Disasters and Chinese Response. China Meteorological Press, Beijing, 187 pp. (in Chinese)
Li, T., B. Wang, B. Wu, et al., 2017: Theories on formation of an anomalous anticyclone in western North Pacific during El Niño: A review. J. Meteor. Res., 31, 987–1006, doi: https://doi.org/10.1007/s13351-017-7147-6.
Li, W. J., 1999: General atmospheric circulation anomaly in 1998 and their impact on climate anomaly in China. Meteor. Mon., 25, 20–25, doi: 10.966/jj.issn.l000-0226.1999.04.004. (in Chinese)
Liu, Y. M., G. X. Wu, H. Liu, et al., 1999: The effect of spatially nonuniform heating on the formation and variation of sub-tropical high. Part III: Condensation heating and South Asian high and western Pacific subtropical high. Acta Meteor. Sinica, 57, 525–538, doi: https://doi.org/10.11676/qxxb1999.051. (in Chinese)
Liu, Y. Y., W. J. Li, W. X. Ai, et al., 2012: Reconstruction and application of the monthly western North Pacific subtropical high indices. J. Appl. Meteor. Sci., 23, 414–423. (in Chinese)
Ma, Y., W. Chen, and L. Wang, 2011: A comparative study of the interannual variation of summer rainfall anomalies between the Huaihe Meiyu season and the Jiangnan Meiyu season and their climate background. Acta Meteor. Sinica, 69, 334–343, doi: https://doi.org/10.11676/qxxb2011.028. (in Chinese)
Marshall, J., Y. Kushnir, D. Battisti, et al., 2001: North Atlantic climate variability: Phenomena, impacts and mechanisms. Int. J. Climatol., 21, 1863–1898, doi: https://doi.org/10.1002/joc.693.
Nitta, T., 1987: Convective activities in the tropical western Pacific and their impact on the Northern Hemisphere summer circulation. J. Meteor. Soc. Japan, 65, 373–390, doi: https://doi.org/10.2151/jmsj1965.65.3_373.
Peng, J. B., L. T. Chen, and Q. Y. Zhang, 2005: Multi-scale variations of snow cover over QXP and tropical Pacific SST and their influences on summer rainfall in China. Plateau Meteor., 24, 366–377, doi: https://doi.org/10.3321/j.issn:1000-0534.2005.03.013. (in Chinese)
Qian, Y. F., Y. Q. Zheng, Y. Zhang, et al., 2003: Responses of China’s summer monsoon climate to snow anomaly over the Tibetan Plateau. Int. J. Climatol., 23, 593–613, doi: https://doi.org/10.1002/joc.901.
Ren, H.-C., W. J. Li, H.-L. Ren, et al., 2016: Distinct linkage between winter Tibetan Plateau snow depth and early summer Philippine Sea anomalous anticyclone. Atmos. Sci. Lett., 17, 223–229, doi: https://doi.org/10.1002/asl.646.
Ren, H.-L., B. Lu, J. H. Wan, et al., 2018: Identification standard for ENSO events and its application to climate monitoring and prediction in China. J. Meteor. Res., 32, 923–936, doi: https://doi.org/10.1007/s13351-018-8078-6.
Ren, Z. H., Y. Yu, F. L. Zou, et al., 2012: Quality detection of surface historical basic meteorological data. J. Appl. Meteor. Sci., 23, 739–747, doi: https://doi.org/10.3969/j.issn.1001-7313.2012.06.011. (in Chinese)
Reynolds, R. W., N. A. Rayner, T. M. Smith, et al., 2002: An improved in situ and satellite SST analysis for climate. J. Climate, 15, 1609–1625, doi: https://doi.org/10.1175/1520-0442(2002)015<1609:AIISAS>2.0.CO;2.
Shi, N., Q. G. Zhu, and B. G. Wu, 1996: The East Asian summer monsoon in relation to summer large scale weather-climate anomaly in China for last 40 years. Chinese J. Atmos. Sci., 20, 575–583, doi: https://doi.org/10.3878/j.issn.l006-9895.1996.05.08. (in Chinese)
Sun, S., D. Li, Z. Y. Wang, et al., 2019: Global major weather and climate events in 2018 and the possible causes. Meteor. Mon., 45, 533–542. (in Chinese)
Sung, M.-K., W.-T. Kwon, H.-J. Baek, et al., 2009: A possible impact of the North Atlantic Oscillation on the East Asian summer monsoon precipitation. Geophys. Res. Lett., 33, L21713, doi: https://doi.org/10.1029/2006GL027253.
Tao, S. Y., and Q. Y. Zhang, 1998: Response of the Asian winter and summer monsoon to ENSO events. Chinese J. Atmos. Sci., 22, 399–407, doi: https://doi.org/10.3878/j.issn.1006-9895.1998.04.02. (in Chinese)
Wang, B., R. G. Wu, and X. H. Fu, 2000: Pacific-East Asian tele-connection: How does ENSO affect East Asian climate? J. Climate, 13, 1517–1536, doi: https://doi.org/10.1175/1520-0442(2000)013<1517:PEATHD>2.0.CO;2.
Wang, L., and W. Gu, 2016: The eastern China flood of June 2015 and its causes. Sci. Bull., 61, 178–184, doi: https://doi.org/10.1007/s11434-015-0967-9.
Wu, G. X., Y. M. Liu, B. He, et al., 2018: Review of the impact of the Tibetan Plateau sensible heat driven air-pump on the Asian summer monsoon. Chinese J. Atmos. Sci., 42, 488–504, doi: https://doi.org/10.3878/j.issn.1006-9895.1801.17279. (in Chinese)
Xie, S.-P., K. M. Hu, J. Hafner, et al., 2009: Indian Ocean capacitor effect on Indo-western Pacific climate during the summer following El Niño. J. Climate, 22, 730–747, doi: https://doi.org/10.1175/2008JCLI2544.1.
Xie, S.-P., Y. Kosaka, Y. Du, et al., 2016: Indo-western Pacific Ocean capacitor and coherent climate anomalies in post-ENSO summer: A review. Adv. Atmos. Sci., 33, 411–432, doi: https://doi.org/10.1007/s00376-015-5192-6.
Xu, P. Q., L. Wang, W. Chen, et al., 2019a: Structural changes in the Pacific-Japan pattern in the late 1990s. J. Climate, 32, 607–621, doi: https://doi.org/10.1175/JCLI-D-18-0123.1.
Xu, P. Q., L. Wang, and W. Chen, 2019b: The British-Baikal corridor: A teleconnection pattern along the summertime polar front jet over Eurasia. J. Climate, 32, 877–896, doi: https://doi.org/10.1175/JCLI-D-18-0343.1.
Ye, D. Z., S. W. Luo, and B. Z. Zhu, 1957: Wind structure and heat balance in the lower troposphere over the Tibetan Plateau and its surrounding. Acta Meteor. Sinica, 28, 108–121, doi: https://doi.org/10.11676/qxxb1957.010. (in Chinese)
Yuan, Y., H. Gao, and Y. J. Liu, 2017: Analysis of the characteristics and causes of precipitation anomalies over eastern China in the summer of 2016. Meteor. Mon., 43, 115–121. (in Chinese)
Zhan, R. F., G. W. Sun, B. K. Zhao, et al., 2008: Quasi-biweekly oscillation of the subtropical summer monsoon rainfall over East China and its possible maintaining mechanism. Plateau Meteor., 27, 98–108. (in Chinese)
Zhang, H. X., W. P. Li, and W. J. Li, 2018: Influence of late springtime surface sensible heat flux anomalies over the Tibetan and Iranian Plateaus on the location of the South Asian high in early summer. Adv. Atmos. Sci., 36, 93–103, doi: https://doi.org/10.1007/s00376-018-7296-2.
Zhang, Q. Y., and S. Y. Tao, 2003: The anomalous subtropical anticyclone in western Pacific and their association with circulation over East Asia during summer. Chinese J. Atmos. Sci., 27, 369–380, doi: https://doi.org/10.3878/j.issn.l006-9895.2003.03.07. (in Chinese)
Zhang, Q. Y., S. Y. Tao, and L. T. Chen, 2003: The interannual variability of East Asian summer monsoon indices and its association with the pattern of general circulation over East Asia. Acta Meteor. Sinica, 61, 559–568, doi: https://doi.org/10.11776/qxxb2003.056. (in Chinese)
Zhang, R. H., A. Sumi, and M. Kimoto, 1996: Impact of El Niño on the East Asian monsoon: A diagnostic study of the’ 86/87 and’ 91/92 events. J. Meteor. Soc. Japan, 74, 49–62, doi: https://doi.org/10.2151/jmsj1965.74.1_49.
Zhang, R. H., Q. Y. Min, and J. Z. Su, 2017: Impact of El Niño on atmospheric circulations over East Asia and rainfall in China: Role of the anomalous western North Pacific anticyclone. Sci. China Earth Sci., 60, 1124–1132, doi: https://doi.org/10.1007/s11430-016-9026-x.
Zhang, S. L., and S. Y. Tao, 2001: Influences of snow cover over the Tibetan Plateau on Asian summer monsoon. Chinese J. Atmos. Sci., 25, 372–390, doi: https://doi.org/10.3878/j.issn.1006-9895.2001.03.07. (in Chinese)
Zhang, Y., 2004: Research on the characteristics of the thermal parameters of the Tibetan Plateau and its climate effects. Ph.D. dissertation, Nanjing University, China, 18 pp. (in Chinese)
Zhao, C. B., T. J. Zhou, B. Li, et al., 2011: Intraseasonal oscillation of summer rainfall over eastern China simulated with a regional climate model. Chinese J. Atmos. Sci., 35, 1033–1045, doi: https://doi.org/10.3878/j.issn.1006-9895.2011.06.04. (in Chinese)
Zhao, J. H., R. Zhi, Q. Shen, et al., 2014: Prediction of the distribution of the 2012 summer rainfall in China and analysis of the cause for anomaly. Chinese J. Atmos. Sci., 38, 237–250, doi: https://doi.org/10.3878/j.issn.1006-9895.2013.12215. (in Chinese)
Zhu, C. W., J. H. He, and G. X. Wu, 2000: East Asian monsoon index and its interannual relationship with large scale thermal dynamic circulation. Acta Meteor. Sinica, 58, 391–402, doi: https://doi.org/10.11676/qxxb2000.042. (in Chinese)
Zhu, Y. X., Y. H. Ding, and H. G. Xu, 2007: The decadal relationship between atmospheric heat source of winter and spring snow over Tibetan Plateau and rainfall in East China. Acta Meteor. Sinica, 65, 946–958, doi: https://doi.org/10.11676/qxxb2007.089. (in Chinese)
Zuo, J. Q., W. J. Li, H.-L. Ren, et al., 2012: Change of the relationship between spring NAO and East Asian summer monsoon and its possible mechanism. Chinese J. Geophys., 55, 384–395. (in Chinese)
Zuo, J. Q., W. J. Li, C. H. Sun, et al., 2013: Impact of the North Atlantic sea surface temperature tripole on the East Asian summer monsoon. Adv. Atmos. Sci., 30, 1173–1186, doi: https://doi.org/10.1007/s00376-012-2125-5.
Zuo, J. Q., W. J. Li, C. H. Sun, et al., 2018: Remote forcing of the northern tropical Atlantic SST anomalies on the western North Pacific anomalous anticyclone. Climate Dyn., 22, 2837–2853, doi: https://doi.org/10.1007/s00382-018-4298-9.
Zwiers, F. W., 1993: Simulation of the Asian summer monsoon with the CCC GCM-1. J. Climate, 6, 470–486, doi: https://doi.org/10.1175/1520-0442(1993)006<0469:SOTASM>2.0.CO;2.
Acknowledgments
We thank the four anonymous reviewers for their constructive comments that led to improvements to this paper.
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by the National Key Research and Development Program of China (2018YFC1506006), National Science and Technology Support Program of China (2015BAC03B04), and National Natural Science Foundation of China (41805067 and 41275073).
Electronic supplementary material
Rights and permissions
About this article
Cite this article
Chen, L., Gu, W. & Li, W. Why Is the East Asian Summer Monsoon Extremely Strong in 2018?—Collaborative Effects of SST and Snow Cover Anomalies. J Meteorol Res 33, 593–608 (2019). https://doi.org/10.1007/s13351-019-8200-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s13351-019-8200-4