Enhanced connections between summer precipitation over the Three-River-Source region of China and the global climate system
- 133 Downloads
This study reveals an enhanced correlation between the interannual variability of summer precipitation over the Three-River-Source (TRS) region of China and North Atlantic Oscillation (NAO), western Indian Ocean sea surface temperature (SST), El Niño-Southern Oscillation (ENSO), and the East Asian summer monsoon (EASM) for past decades, revealing an enhanced connection between the summer climate of the TRS region and the global climate system. Underlying causes are investigated based on a comparison on the climate effects associated with the aforementioned factors between periods 1961–1980 and 1991–2014. Enhanced connections to NAO are mainly attributed to the fact that the increased atmospheric moisture over the Arctic region has an enhanced latent heating on convective activity over the Hudson Bay-Davis Strait region under negative-phase NAO, generating an intensified anomalous high over Greenland and further stimulating an Eurasian wave-train influencing the TRS region. Similarly, for an El-Niño decaying summer, convection anomalies over the Maritime Continent are more significant due to enhanced latent heating observed in 1991–2014, which in turn have a more significant influence on the summer climate in TRS region. Regarding western Indian Ocean SSTs, warming in the western Indian Ocean is characterized by a warming center north (south) of the equator for 1991–2014 (1961–1980); correspondingly, the associated Kelvin wave-induced Ekman divergence mechanism is more pronounced over the Bay of Bengal and South China Sea for 1991–2014. Enhanced connections to the EASM are mainly attributable to a combined effect of Indian Ocean warming and anomalous convective activity over the Maritime Continent associated with ENSO.
KeywordsThree-River-Source Precipitation Interannual variability NAO ENSO Indian Ocean
This study is funded by the National Key Research and Development Program of China (2016YFA0600703), the Jiangsu Innovation and Entrepreneurship Team, the Startup Foundation for Introducing Talent of NUIST (No. 2243141701093), and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
- Huang RH (1992) The East Asia/Pacific pattern teleconnection of summer circulation and climate anomaly in East Asia. Acta Meteorol Sin 6:25–37Google Scholar
- Hurrell JW, Kushinir Y, Ottersen G, Visbeck M (2003) An overview of the North Atlantic Oscillation. In: Hurrell JW, Kushnir Y, Ottersen G, Visbeck M (eds) The North Atlantic Oscillation: climatic significance and environmental impact. American Geophysical Union, Washington, pp 1–35. https://doi.org/10.1029/134GM01 CrossRefGoogle Scholar
- Kalnay E, Kanamitsu M, Kistler R, Collins W, Deaven D, Gandin L, Iredell L, Saha S, White G, Woollen J, Zhu Y, Leetmaa A, Reynolds R, Chelliah M, Ebisuzaki W, Higgins W, Janowiak J, Mo KC, Ropelewski C, Wang J, Jenne R, Joseph D (1996) The NCEP/NCAR 40-year reanalysis project. Bull Am Meteor Soc 77:437–470CrossRefGoogle Scholar
- Li S, Li D, Zhao P, Zhang G (2009) The climatic characteristics of vapor transportation in rainy season of the origin area of three rivers in Qinghai-Xizang Plateau. Acta Meteorol Sin 67:591–598 (in Chinese) Google Scholar
- Saji NH, Goswami BN, Vinayachandran PN, Yamagata T (1999) A dipole mode in the tropical Indian Ocean. Nature 401:360–363Google Scholar