Abstract
Rainfall amount in mid-summer (July and August) is much greater over eastern than western Sichuan, which are characterized by basin and plateau, respectively. It is shown that the interannual variations of extreme rainfall over these two regions are roughly independent, and they correspond to distinct anomalies of both large-scale circulation and sea surface temperature (SST). The enhanced extreme rainfall over western Sichuan is associated with a southward shift of the Asian westerly jet, while the enhanced extreme rainfall over eastern Sichuan is associated with an anticyclonic anomaly in the upper troposphere over China. At low levels, on the other hand, the enhanced extreme rainfall over western Sichuan is related to two components of wind anomalies, namely southwesterly over southwestern Sichuan and northeasterly over northeastern Sichuan, which favor more rainfall under the effects of the topography. Relatively speaking, the enhanced extreme rainfall over eastern Sichuan corresponds to the low-level southerly anomalies to the east of Sichuan, which curve into northeasterly anomalies over the basin when they encounter the mountains to the north of the basin. Therefore, it can be concluded that the topography in and around Sichuan plays a crucial role in inducing extreme rainfall both over western and eastern Sichuan. Finally, the enhanced extreme rainfall in western and eastern Sichuan is related to warmer SSTs in the Maritime Continent and cooler SSTs in the equatorial central Pacific, respectively.
摘 要
四川东部盆地盛夏(7、8月)的降水量显著大于四川西部的高原地区。本研究发现,四川东西部极端降水的年际变化基本是相互独立的,分别对应不同的大尺度环流和海温异常。在对流层高层,川西地区极端降水的偏多与亚洲西风急流位置偏南有关,而川东地区极端降水的偏多则与中国上空的反气旋异常环流相联系。在对流层低层,川西地区极端降水的偏多对应四川西南上空的西南风异常和四川东北上空的东北风异常。在地形作用的影响下,这两支风场异常都有利于川西地区降水增加。相对而言,川东地区极端降水的偏多对应四川以东的低层南风异常。该南风异常受盆地北部的山脉阻挡,在盆地上空转为东北风异常,有利于川东地区的降水。因此,四川及其周边地区的地形是川西和川东极端降水异常的重要因素。此外,川西地区极端降水的偏多对应海洋性大陆周边的暖海温异常,而川东地区极端降水的偏多则对应赤道中太平洋的冷海温异常。
Similar content being viewed by others
References
Amante, C., and B. W. Eakins, 2009: ETOP01 1 arc-minute global relief model: Procedures, data sources and analysis. NOAA Technical Memorandum NESDIS NGDC-24, 19 pp, https://doi.org/10.7289/V5C8276M.
Chen, Q. L., X. R. Liu, Z. G. Fan, and W. Hua, 2010: Features of summer precipitation change over the West Sichuan Plateau and its relationship with large-scale circulations. Journal of Desert Research, 30(3), 706–711. (in Chinese with English abstract)
Dee, D. P., and Coauthors, 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation system. Quart. J. Roy. Meteor. Soc., 137(656), 553–597, https://doi.org/10.1002/qj.828.
Deng, G. W., J. Sun, G. B. Ruan, and Z. F. Ma, 2017: Rainstorm and flood disaster characteristics and analysis of circulation background in main flood season in Sichuan. Plateau Meteorology, 36(6), 1521–1532, https://doi.org/10.7522/j.issn.1000-0534.2016.00099. (in Chinese with English abstract)
Hu, D. Q., R. Y. Lu, Q. Su, and G. Z. Fan, 2014: Interannual variation in the mid-summer rainfall over the western Sichuan Basin and the associated circulation anomalies. Chinese Journal of Atmospheric Sciences, 38(1), 13–20, https://doi.org/10.3878/j.issn.1006-9895.2013.12192. (in Chinese with English abstract)
Huang, B., and Coauthors, 2017: Extended reconstructed sea surface temperature, version 5 (ERSSTv5): Upgrades, validations, and intercomparisons. J. Climate, 30(20), 8179–8205, https://doi.org/10.1175/JCLI-D-16-0836.1.
Ji, Y. H., G. S. Zhou, S. D. Wang, and L. X. Wang, 2015: Increase in flood and drought disasters during 1500–2000 in Southwest China. Natural Hazards, 77(3), 1853–1861, https://doi.org/10.1007/s11069-015-1679-9.
Jiang, X. W., Y. Q. Li, S. Yang, J. C. Shu, and G. B. He, 2015: Interannual variation of mid-summer heavy rainfall in the eastern edge of the Tibetan Plateau. Climate Dyn., 45(11), 3091–3102, https://doi.org/10.1007/s00382-015-2526-0.
Jiang, X. W., Y. Q. Li, S. Yang, K. Yang, and J. W. Chen, 2016: Interannual variation of summer atmospheric heat source over the Tibetan Plateau and the role of convection around the western Maritime Continent. J. Climate, 29(1), 121–138, https://doi.org/10.1175/JCLI-D-15-0181.1
Li, Q., S. Yang, X. P. Cui, and L. K. Ran, 2016: Diagnosis and forecasting of dynamical parameters for a heavy rainfall event in Sichuan province. Chinese Journal of Atmospheric Sciences, 40(2), 341–356, https://doi.org/10.3878/j.issn.1006-9895.1507.14296. (in Chinese with English abstract)
Li, Z. X., and Coauthors, 2012: Changes of daily climate extremes in southwestern China during 1961–2008. Global and Planetary Change, 80–81, 255–272, https://doi.org/10.1016/j.gloplacha.2011.06.008.
Liang, P., W. Li, L. X. Chen, J. H. He, and Z. J. Ren, 2005: Features and sources of the anomalous moisture transport for the severe summer rainfall over the upper reaches of the Yangtze River. Journal of Meteorological Research, 19(2), 202–215.
Lu, R. Y., 2004: Associations among the Components of the East Asian Summer Monsoon System in the Meridional Direction. J. Meteor. Soc. Japan Ser. II, 82(1), 155–165, https://doi.org/10.2151/JMSJ.82.155.
Lu, R. Y., and H. Ye, 2011: Decreasing trend in summer precipitation over the western Sichuan basin since the 1950s. Atmos. Ocean. Sci. Lett., 4(2), 114–117, https://doi.org/10.1080/16742834.2011.11446915.
Lu, R. Y., and S. Lu, 2014: Local and remote factors affecting the SST-precipitation relationship over the western North Pacific during Summer. J. Climate, 27(13), 5132–5147, https://doi.org/10.1175/JCLI-D-13-00510.1.
Qian, T. T., P. Zhao, F. Q. Zhang, and X. H. Bao, 2015: Rainy-season precipitation over the Sichuan basin and adjacent regions in southwestern China. Mon. Wea. Rev., 143(1), 383–394, https://doi.org/10.1175/MWR-D-13-00158.1.
Qian, W., H. S. Kang, and D. K. Lee, 2002: Distribution of seasonal rainfall in the east Asian monsoon region. Theor. Appl. Climatol., 73(3), 151–168, https://doi.org/10.1007/s00704-002-0679-3.
Sun, C., J. P. Li, and R. Q. Ding, 2016: Strengthening relationship between ENSO and western Russian summer surface temperature. Geophys. Res. Lett., 43(2), 843–851, https://doi.org/10.1002/2015GL067503.
Tan, W., Z. X. Wei, Q. Liu, Q. J. Fu, M. Y. Chen, B. T. Li, and J. Li, 2020: Different influences of two El Niño Types on low-level atmospheric circulation over the subtropical western North Pacific. J. Climate, 33(3), 825–846, https://doi.org/10.1175/JCLI-D-19-0223.1.
Uppala, S. M., and Coauthors, 2005: The ERA-40 re-analysis. Quart. J. Roy. Meteor. Soc., 131(612), 2961–3012, https://doi.org/10.1256/qj.04.176.
You, Q. L., S. C. Kang, E. Aguilar, and Y. P. Yan, 2008: Changes in daily climate extremes in the eastern and central Tibetan Plateau during 1961–2005. J. Geophys. Res.: Atmos., 113, D07101, https://doi.org/10.1029/2007JD009389.
Zeng, W., Z. Yu, S. H. Wu, and J. B. Qin, 2016: Changes in annual, seasonal and monthly precipitation events and their link with elevation in Sichuan province, China. International Journal of Climatology, 36(5), 2303–2322, https://doi.org/10.1002/joc.4496.
Zhai, P. M., X. B. Zhang, H. Wan, and X. H. Pan, 2005: Trends in total precipitation and frequency of daily precipitation extremes over China. J. Climate, 18(7), 1096–1108, https://doi.org/10.1175/JCLI-3318.1.
Zhang, Q., and Y. Q. Li, 2014: Climatic variation of rainfall and rain day in Southwest China for last 48 years. Plateau Meteorology, 33(2), 372–383, https://doi.org/10.7522/j.issn.1000-0534.2013.00032. (in Chinese with English abstract)
Zhao, B., and Coauthors, 2021: Emergency response to the reactivated Aniangzhai landslide resulting from a rainstorm-triggered debris flow, Sichuan province, China. Landslides, 18(3), 1115–1130, https://doi.org/10.1007/s10346-020-01612-2.
Acknowledgements
This work was supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDA23090102) and the Second Tibetan Plateau Scientific Expedition and Research (STEP) program (Grant No. 2019QZKK0102).
Author information
Authors and Affiliations
Corresponding author
Additional information
Article Highlights
• Interannual variations of extreme rainfall over western and eastern Sichuan are roughly independent.
• Interannual variations of extreme rainfall over western and eastern Sichuan correspond to distinct circulation and SST anomalies.
• Topography induces extreme rainfall both over western and eastern Sichuan through modulating lower-level wind anomalies.
Rights and permissions
About this article
Cite this article
Deng, M., Lu, R. & Li, C. Contrasts between the Interannual Variations of Extreme Rainfall over Western and Eastern Sichuan in Mid-summer. Adv. Atmos. Sci. 39, 999–1011 (2022). https://doi.org/10.1007/s00376-021-1219-3
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00376-021-1219-3