A large amount of accumulated precipitation was recorded over the Eastern Periphery of the Tibetan Plateau (EPTP) in August 2020. Using hourly rain gauge records and the ERA5 reanalysis dataset, we analyzed the unique characteristics of rainfall in August and the accompanying circulation conditions and conducted a comparison with previous data. This record-breaking amount of accumulated rainfall was centered on the northern slope of the EPTP. This location was in contrast with the historical records of the concentration of rainfall over the middle and southern slopes. The hourly rainfall in August 2020 was both more frequent and more intense than the climatological mean rainfall. An amplification effect of the topography was observed, with the precipitation over the EPTP showing a more significant change with terrain height in August 2020. A circulation analysis showed that cold (warm) anomalies existed over the north (south) of approximately 35°N compared with those in the years when the southern EPTP received more rain. The western Pacific subtropical high was more intense and extended to the west, and the low-level cold air from the north was more active. The enhanced low-level southerly winds on the periphery of the subtropical high injected warm, moist air further north than the climatological mean. These winds became easterly near the northern EPTP and were forced to ascend by the steep terrain.
2020 年 8 月在青藏高原东坡出现了异常大的累积降水量. 利用逐小时站点观测资料和 ERA5 再分析数据, 本文分析了 2020 年 8 月降水的独特特征和对应的环流条件, 并与历史记录进行了比较. 这一创纪录的累积降水量集中在青藏高原东坡的北段. 该位置与历史记录中降水集中在中坡和南坡的情况明显不同. 相比气候平均, 2020 年 8 月的小时降水更加频繁、 强度更强. 2020 年 8 月, 青藏高原东坡地形对降水的增幅效应比以往更加明显. 环流分析表明, 与降水集中在青藏高原东坡南段的年份相比, 降水集中在北段时, 在约 35°N 以北 (以南) 存在冷 (暖) 异常. 西太平洋副热带高压强度更强, 并向西延伸, 来自北部的低层冷空气更活跃. 副热带高压外围增强的低层偏南风将暖湿空气注入比多年平均更北的地方, 并在青藏高原东坡北段附近转为偏东风, 在陡峭地形的作用下强迫上升.
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Araki, K., T. Kato, Y. Hirockawa, and W. Mashiko, 2021: Characteristics of atmospheric environments of quasi-stationary convective bands in Kyushu, Japan during the July 2020 heavy rainfall event. SOLA, 17, 8–15, https://doi.org/10.2151/sola.2021-002.
Chen, G. X., 2020: Diurnal cycle of the Asian summer monsoon: Air pump of the second kind. J. Climate, 33(5), 1747–1775, https://doi.org/10.1175/JCLI-D-19-0210.1.
Chen, H. M., J. Li, and R. C. Yu, 2018: Warm season nocturnal rainfall over the eastern periphery of the Tibetan Plateau and its relationship with rainfall events in adjacent regions. International Journal of Climatology, 38(13), 4786–4801, https://doi.org/10.1002/joc.5696.
Chen, Q.-G., Z.-Y. Cai, and C.-L. Bao, 1963: An analysis of the physical mechanism of the precipitation process in West Szechuan. Journal of Nanjing University (Natural Science), 1–24. (in Chinese with English abstract)
Chen, T., F. H. Zhang, C. Yu, J. Ma, X. D. Zhang, X. L. Shen, F. Zhang, and Q. Luo, 2020: Synoptic analysis of extreme Meiyu precipitation over Yangtze River basin during June–July 2020. Meteorological Monthly, 46(11), 1415–1426, https://doi.org/10.7519/j.issn.1000-0526.2020.11.003. (in Chinese with English abstract)
Heng, Z. W., and P. Li, 2017: Analysis of summer precipitation on the eastern flank of the Tibetan Plateau with PR data. Plateau and Mountain Meteorology Research, 37, 10–15, https://doi.org/10.3969/j.issn.1674-2184.2017.03.002. (in Chinese with English abstract)
Hersbach, H., and Coauthors, 2020: The ERA5 global reanalysis. Quart. J. Roy. Meteor. Soc., 146(730), 1999–2049, https://doi.org/10.1002/qj.3803.
Hu, X. L., and W. H. Yuan, 2021: Evaluation of ERA5 precipitation over the eastern periphery of the Tibetan Plateau from the perspective of regional rainfall events. International Journal of Climatology, 41(4), 2625–2637, https://doi.org/10.1002/joc.6980
Hu, X. L., W. H. Yuan, R. C. Yu, and M. H. Zhang, 2020: The evolution process of warm season intense regional rainfall events in Yaan. Climate Dyn., 54(7–8), 3245–3258, https://doi.org/10.1007/s00382-020-05168-8.
Li, D. Y., L. Wang, and L. Zou, 2016: Analysis of strong precipitation in a continuous warm area in the western Sichuan Plateau. Plateau and Mountain Meteorology Research, 36, 81–85, https://doi.org/10.3969/j.issn.1674-2184·2016.01.013. (in Chinese with English abstract)
Li, J., R. C. Yu, W. H. Yuan, H. M. Chen, W. Sun, and Y. Zhang, 2015: Precipitation over East Asia simulated by NCAR CAM5 at different horizontal resolutions. Journal of Advances in Modeling Earth Systems, 7, 774–790, https://doi.org/10.1002/2014MS000414.
Li, Y. Q., D. J. Li, S. Yang, C. Liu, A. H. Zhong, and Y. Li, 2010: Characteristics of the precipitation over the eastern edge of the Tibetan Plateau. Meteorol. Atmos. Phys., 106(1), 49–56, https://doi.org/10.1007/s00703-009-0048-1.
Liu, B. Q., Y. H. Yan, C. W. Zhu, S. M. Ma, and J. Y. Li, 2020: Record-breaking Meiyu rainfall around the Yangtze River in 2020 regulated by the subseasonal phase transition of the North Atlantic oscillation. Geophys. Res. Lett., 47(22), e2020GL090342, https://doi.org/10.1029/2020GL090342.
Liu, Y. Y., and Y. H. Ding, 2020: Characteristics and possible causes for the extreme Meiyu in 2020. Meteorological Monthly, 46(11), 1393–1404, https://doi.org/10.7519/j.issn.1000-0526.2020.11.001. (in Chinese with English abstract)
Liu, Y. Y., Y. G. Wang, and Z. J. Ke, 2021: Characteristics and possible causes for the climate anomalies over China in summer 2020. Meteorological Monthly, 47(1), 117–126, https://doi.org/10.7519/j.issn.1000-0526.2021.01.011. (in Chinese with English abstract)
Takaya, Y., I. Ishikawa, C. Kobayashi, H. Endo, and T. Ose, 2020: Enhanced Meiyu-baiu rainfall in early summer 2020: Aftermath of the 2019 super IOD event. Geophys. Res. Lett., 47(22), e2020GL090671, https://doi.org/10.1029/2020GL090671.
Wang, B., and L. Ho, 2002: Rainy season of the Asian-Pacific summer monsoon. J. Climate, 15(4), 386–398, https://doi.org/10.1175/1520-0442(2002)015<0386:RSOTAP>2.0.CO;2.
Wang, B. J., Y. X. Huang, D. Wei, J. X. Wang, X. W. Liu, W. B. Huang, W. C. Liu, and X. J. Yang, 2017: Structure analysis of heavy precipitation over the eastern slope of the Tibetan Plateau based on TRMM data. Acta Meteorologica Sinica, 75, 966–980, https://doi.org/10.11676/qxxb2017.062. (in Chinese with English abstract)
Wang, Y. G., D. J. Lou, and Y. Y. Liu, 2020: Characteristics and causes analysis of abnormal Meiyu rainfall in the middle and lower reaches of Yangtze River Valley in 2020. Torrential Rain and Disasters, 39(6), 549–554, https://doi.org/10.3969/j.issn.1004-9045.2020.06.001. (in Chinese with English abstract)
Wei, K., C. J. Ouyang, H. T. Duan, Y. L. Li, M. X. Chen, J. Ma, H. C. An, and S. Zhou, 2020: Reflections on the catastrophic 2020 Yangtze River basin flooding in southern China. The Innovation, 1(2), 100038, https://doi.org/10.1016/j.xinn.2020.100038.
Xi, G. C., 1992: Climatic characteristics of Ya’an regional heavy rainfall. Sichuan Meteorology, 7–15. (in Chinese with English abstract)
Xiao, H. R., J. J. Wang, D. X. Xiao, K. J. Long, and Y. Chen, 2021: Analysis of warm-sector rainstorm characteristics over Sichuan basin. Meteorological Monthly, 47, 303–316, https://doi.org/10.7519/j.issn.1000-0526.2021.03.004. (in Chinese with English abstract)
Xu, C., and T.-G. Xiao, 2015: Analysis of strong precipitation process based on the FY-2E satellite data in western Sichuan. Journal of Chengdu University of Information Technology, 30, 481–490, https://doi.org/10.3969/j.issn.1671-1742.2015.05.013. (in Chinese with English abstract)
Yu, R. C., W. Li, X. H. Zhang, Y. M. Liu, Y. Q. Yu, H. L. Liu, and T. J. Zhou, 2000: Climatic features related to Eastern China summer rainfalls in the NCAR CCM3. Adv. Atmos. Sci., 17(4), 503–518, https://doi.org/10.1007/s00376-000-0014-9.
Yu, R. C., T. J. Zhou, A. Y. Xiong, Y. J. Zhu, and J. M. Li, 2007: Diurnal variations of summer precipitation over contiguous China. Geophys. Res. Lett., 34(1), L01704, https://doi.org/10.1029/2006GL028129.
Yuan, W. H., R. C. Yu, M. H. Zhang, W. Y. Lin, J. Li, and Y. F. Fu, 2013: Diurnal cycle of summer precipitation over subtropical East Asia in CAM5. J. Climate, 26(10), 3159–3172, https://doi.org/10.1175/JCLI-D-12-00119.1.
Zeng, Q. C., R. C. Yu, G. K. Peng, and F. X. Chai, 1994: Research on ‘Ya-An-Tian-Lou’ Part III: The physical structure and possible mechanism. Scientia Atmospherica Sinica, 18, 649–659, https://doi.org/10.3878/j.issn.1006-9895.1994.06.02. (in Chinese with English abstract)
Zhang, F. H., T. Chen, F. Zhang, X. L. Shen, and Y. Lan, 2020: Extreme features of severe precipitation in Meiyu period over the middle and lower reaches of Yangtze River basin in June–July 2020. Meteorological Monthly, 46(11), 1405–1414, https://doi.org/10.7519/j.issn.1000-0526.2020.11.002. (in Chinese with English abstract)
Zhang, Q., Y. F. Zhao, and S. H. Fan, 2016: Development of hourly precipitation datasets for national meteorological stations in China. Torrential Rain and Disasters, 35, 182–186, https://doi.org/10.3969/j.issn.1004-9045.2016.02.011. (in Chinese with English abstract)
Zhao, Y. C., X. F. Xu, and C. G. Cui, 2012: A study of convective rainstorms along the east slope of Western Sichuan Plateau. Climatic and Environmental Research, 17, 607–616, https://doi.org/10.3878/j.issn.1006-9585.2011.11056. (in Chinese with English abstract)
Zhou, C. C., and P. P. Wu, 2015: Comparison analysis of two warm sector torrential rain weathers on the east side of Tibetan Plateau. Plateau and Mountain Meteorology Research, 35, 1–8, https://doi.org/10.3969/j.issn.1674-2184.2015.01.001. (in Chinese with English abstract)
Zhou, Z.-Q., S.-P. Xie, and R. H. Zhang, 2021: Historic Yangtze flooding of 2020 tied to extreme Indian Ocean conditions. Proceedings of the National Academy of Sciences of the United States of America, 118(12), e2022255118, https://doi.org/10.1073/pnas.2022255118.
Zhu, Y. F., and R. C. Yu, 2003: Interannual variation of summer precipitation in the west of Sichuan basin and its relationship with large-scale circulation. Chinese Journal of Atmospheric Sciences, 27(6), 1045–1056, https://doi.org/10.3878/j.issn.1006-9895.2003.06.08. (in Chinese with English abstract)
This work was jointly supported by the National Key R&D Program of China (Grant No. 2018YFC1507603) and the National Natural Science Foundation of China (Grant No. 41875112).
• In August 2020, the precipitation in the northern slope of the EPTP was more frequent and intense than the climatological mean, and the variation of precipitation with terrain height was more significant than that in previous years.
• The western Pacific subtropical high was stronger in August 2020 and extended westward.
• The enhanced low-level southerly wind on the periphery of the subtropical high injected warm, moist air further north than the climatological mean, which was conducive to the occurrence of heavy precipitation.
This paper is a contribution to the special issue on Summer 2020: Record Rainfall in Asia—Mechanisms, Predictability and Impacts.
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Hu, X., Yuan, W. & Yu, R. The Extraordinary Rainfall over the Eastern Periphery of the Tibetan Plateau in August 2020. Adv. Atmos. Sci. 38, 2097–2107 (2021). https://doi.org/10.1007/s00376-021-1134-7
- intense rainfall
- summer 2020
- Eastern Periphery of the Tibetan Plateau
- western Sichuan Basin
- 2020 年夏季