Amplifying effect of ENSO on heat waves in China
- 279 Downloads
This paper investigates the impacts of the El Niño Southern Oscillation (ENSO) on various aspects of heat waves (HWs), including frequency, duration, and magnitude, over China during 1961–2014. Results show that El Niño (La Niña) significantly amplifies (weakens) the HW activities in most areas of China. Such influences are particularly strong in southern China. HW activities are enhanced (weakened) during the summers following mature El Niño (La Niña) episodes, with increased (reduced) occurrence of HW events and number of HW days, as well as prolonged (shortened) duration and elevated (decreased) amplitude of such events. These amplifying effects are substantially stronger for severe HWs (i.e., hottest and longest episodes) than for those events of average duration and intensity. Diagnosis by compositing reanalysis data over ENSO events indicates that the atmospheric circulation during the summers following El Niño is characterized by anomalous rising motion over the tropical central Pacific and Indian Oceans, and sinking motion over the western North Pacific (WNP). The anomalous subsidence over the WNP is accompanied by reduced precipitation and condensational heating, as well as anomalous anticyclonic flows in the lower troposphere. El Niño also induces a stronger South Asian high, which can strengthen the WNP anticyclone and subtropical high. These changes provide a favorable environment for the occurrence and sustenance of HWs in China. Analogous arguments apply to changes with the opposite polarity in association with La Niña events.
This study is partially supported by the National Natural Science Foundation of China (no. 41401052). The appointment of NCL at The Chinese University of Hong Kong is partially supported by the AXA Research Fund.
- Ding T, Qian W, Yan Z (2010) Changes in hot days and heat waves in China during 1961–2007. Int J Climatol 30:1452–1462Google Scholar
- Grotjahn R, Black R, Leung R, Wehner MF, Barlow M, Bosilovich M, Gershunov A, Gutowski WJ, Gyakum JR, Katz RW, Lee Y-Y, Lim Y-K, Prabhat (2016) North American extreme temperature events and related large scale meteorological patterns: a review of statistical methods, dynamics, modeling, and trends. Clim Dyn 46:1151–1184CrossRefGoogle Scholar
- Kalnay E, Kanamitsu M, Kistler R, Collins W, Deaven D, Gandin L, Iredell M, Saha S, White C, Woollen J, Zhu Y, Chelliah M, Ebisuzaki W, Higgins W, Janowiak J, Mo KC, Ropelewski C, Wang J, Leetmaa A, Reynolds R, Jenne P, Joseph D (1996) The NCEP/NCAR 40-year reanalysis project. Bull Am Meteorol Soc 77:437–471CrossRefGoogle Scholar
- Liang N, Jian L, Bin W (2017) How does the South Asian high influence extreme precipitation over eastern China? J Geophys Res Amos 122:4281–4298Google Scholar
- Rohde R, Muller R, Jacobsen R, Perlmutter S, Rosenfeld A, Wurtele J, Curry J, Wickham C, Mosher S (2013) Berkeley Earth temperature averaging process. Geoinform Geostat Overv 1:1000103Google Scholar
- Wang W, Zhou W, Wang X, Fong SK, Leong KC (2013) Summer high temperature extremes in southeast China associated with the East Asian jet stream and circumglobal teleconnection. J Geophys Res Amos 118:8306–8319Google Scholar
- Xu W, Li Q, Wang XL, Yang S, Cao L, Feng Y (2013) Homogenization of Chinese daily surface air temperatures and analysis of trends in the extreme temperature indices. J Geophys Res Amos 118:9708–9720Google Scholar
- Xu X, Wen C, Shangfeng C, Dingwen Z (2015) Modulation of the connection between boreal winter ENSO and the South Asian high in the following summer by the stratospheric quasi-biennial oscillation. J Geophys Res Amos 120:7393–7411Google Scholar
- Yang J, Liu Q, Xie SP, Liu Z, Wu L (2007) Impact of the Indian Ocean SST basin mode on the Asian summer monsoon. Geophys Res Lett 34:L02708Google Scholar
- Zhang Q, Qian YF, Zhang X (2000) Interannual and interdecadal variations of the South Asia high. Chin J Atmos Sci 24:67–78Google Scholar