Climate Dynamics

, Volume 46, Issue 7–8, pp 2673–2688 | Cite as

Interannual variability of the Asian subtropical westerly jet in boreal summer and associated with circulation and SST anomalies

  • Yin Du
  • Tim Li
  • Zhiqing Xie
  • Zhiwei Zhu


The interannual variability of the Asian Subtropical Westerly Jet (ASWJ) in boreal summer is investigated through the diagnosis of 54-year (1960–2013) NCEP/NCAR reanalysis data. The main characteristics of two leading empirical orthogonal function patterns of 200 hPa zonal wind anomalies are the meridional displacement and southwest–northeast tilting of ASWJ. The first leading mode has significant periods of 4.9 years, whereas the second mode has significant periods of 3.6 and 7.7 years, respectively. The two modes exhibit an equivalent barotropic structure, and are associated with a distinctive north–south and east–west dipole rainfall pattern in China, respectively. The positive phase of the first leading mode appears during El Nino developing phase, whereas the positive phase of the second mode occurs during La Nina decaying phase. A mechanism is put forth based on observational analysis and AGCM sensitivity experiments. The positive phase of the first mode is primarily driven by the combined effect of a cold SST anomaly (SSTA) in mid-latitude North Pacific and a warm SSTA in tropical Indian Ocean and Pacific. In response to the SSTA forcing, a zonally oriented north–south tropospheric temperature dipole is induced. While the tropospheric warming in the tropics arises from El Nino like heating, the tropospheric cooling in the mid-latitudes arises possibly from the local SSTA forcing. For the positive phase of the second mode, the upper-tropospheric anticyclonic vorticity anomaly in the east pole arises from local SSTA forcing in North Pacific, whereas the cyclonic anomaly in the west pole results from southeastward Rossby wave energy emanation from North Atlantic to East Asia.


Asian Subtropical Westerly Jet Meridional temperature gradient Sea surface temperature anomaly AGCM experiments 



This study was supported by China National 973 Project 2015CB453200, NSFC Grants 41205063 and 41475084, Jiangsu Province Grant BK2012888 and BK2011831, and Jiangsu Shuang—Chuang Team. The International Pacific Research Center (IPRC) is partially sponsored by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC). This is SOEST contribution number 1127, IPRC contribution number 1127 and ESMC number 054.


  1. Alexander MA, Blande I, Newman M et al (2002) The atmospheric bridge: the influence of ENSO teleconnections on air–sea interaction over the global oceans. J Clim 15:2205–2231CrossRefGoogle Scholar
  2. Cherchi A, Navarra A (2003) Reproducibility and predictability of the Asian summer monsoon in the ECHAM4-GCM. Clim Dyn 20:365–379Google Scholar
  3. Ding Q, Wang B, Wallace JM et al (2011) Tropical-extratropical teleconnections in boreal summer: observed interannual variability. J Clim 24:1878–1896CrossRefGoogle Scholar
  4. Dong M, Zhu WM, Wei FY (1987) The characteristics of zonal winds at 500 hPa in Eurasian region and its relation to the weather in China. J Appl Meterol Sci 2(2):166–173Google Scholar
  5. Dong M, Yu JR, Gao ST (1999) A study on the variations of the westerly jet over East Asia and Its relation with the tropical convective heating. Chin J Atmos Sci (in Chinese) 23(1):62–70Google Scholar
  6. Du Y, Zhang YC, Xie ZQ (2009) Impacts of the zonal position of the East Asian westerly jet core on precipitation distribution during Meiyu of China. Acta Meteorol Sin 23(4):506–516Google Scholar
  7. Duan AM, Wu GX (2009) Weakening trend in the atmospheric heat source over the Tibetan Plateau during recent decades part II: connection with climate warming. J Clim 22:4197–4212CrossRefGoogle Scholar
  8. Fu XH, Wang B, Li T (2002) Impacts of air–sea coupling on the simulation of mean Asian summer monsoon in the ECHAM4 model. Mon Weather Rev 130:2889–2904CrossRefGoogle Scholar
  9. Gill AE (1980) Some simple solutions for heat-induced tropical circulation. Q J R Meteorol Soc 106:447–462CrossRefGoogle Scholar
  10. Jiang DB, Wang HJ, Lang XM (2005) Evaluation of East Asian climatology as simulated by seven coupled models. Adv Atmos Sci 22(4):479–495CrossRefGoogle Scholar
  11. Kalnay E, Kanamitsu M, Kistler R et al (1996) The NCEP/NCAR 40-year reanalysis project. Bull Am Meteorol Soc 77:437–470CrossRefGoogle Scholar
  12. Krishnamurti TN (1979) Compendium of meteorology part 4: tropical meteorology. World Meteorology Organization, GenevaGoogle Scholar
  13. Kuang XY, Zhang YC (2006) The impacts of position abnormalities of the East Asia subtropical westerly jet on summer precipitation in the middle-lower reaches of the Yangtze River. Plateau Meteorol (in Chinese) 25(3):382–389Google Scholar
  14. Lau NC, Nath MJ (2006) ENSO modulation of the interannual and intraseasonal variability of the East Asian Monsoon—a model study. J Clim 19:4508–4529CrossRefGoogle Scholar
  15. Li T, Wang B (2005) A review on the western North Pacific monsoon: synoptic-to-interannual variabilities. Terr Atmos Ocean Sci 16:285–314Google Scholar
  16. Li CY, Wang ZT, Lin SZ et al (2004) The relationship between east Asian summer monsoon activity and northward jump of the upper westerly jet location. Chin J Atmos Sci (in Chinese) 28(5):641–658Google Scholar
  17. Liao QH, Gao ST, Wang HJ et al (2004) Anomalies of the extratropical westerly jet in the north hemisphere and their impacts on east Asian summer monsoon climate anomalies. Chin J Geophys (in Chinese) 47(1):10–18Google Scholar
  18. Liao QH, Tao SY, Wang HJ (2006) Internal dynamics related to anomalies of seasonal evolution of summer circulations in East Asia during July–August. Chin J Geophys (in Chinese) 49(1):28–36Google Scholar
  19. Lin ZD, Lu RY (2005) Inter-annual meridional displacement of the East Asian up-tropospheric jet stream in summer. Adv Atmos Sci 22(2):199–211CrossRefGoogle Scholar
  20. Lu RY, Ye H, Jhun JG (2011) Weakening of interannual variability in the summer East Asian upper-tropospheric westerly jet since the mid-1990s. Adv Atmos Sci 28(6):1246–1258. doi: 10.1007/s00376-011-0222-5 CrossRefGoogle Scholar
  21. North G, Bell T, Cahalan R et al (1982) Sampling errors in the estimation of empirical orthogonal functions. Mon Weather Rev 110:699–706CrossRefGoogle Scholar
  22. Reinhard S, Daniel L, Christoph S (2009) Seasonality and inter-annual variability of the westerly jet in the Tibetan Plateau Region. J Clim 22:2940–2957CrossRefGoogle Scholar
  23. Reockner E et al (1996) The atmospheric general circulation model ECHAM-4: model description and simulation of present-day climate. Max Planck Institute Rep 218, 90 ppGoogle Scholar
  24. Sampe T, Xie SP (2010) Large-scale dynamics of the Meiyu-Baiu rainband: environmental forcing by the westerly Jet. J Clim 23:113–134CrossRefGoogle Scholar
  25. Smith TM, Reynolds RW (2004) Improved extended reconstruction of SST (1854–1997). J Clim 17:2466–2477CrossRefGoogle Scholar
  26. Takaya K, Nakamura H (2001) A formulation of a phase-independent wave-activity flux for stationary and migratory quasi-geostrophic eddies on a zonally varying basic flow. J Atmos Sci 58:608–627CrossRefGoogle Scholar
  27. Van Storch H, Zwiers FW (1999) Statistical analysis in climate research. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  28. Wallace JM, Kousky VE (1968) Observational evidence of Kelvin waves in the tropical stratosphere. J Atmos Sci 25:900–907CrossRefGoogle Scholar
  29. Wang B, Bao Q, Hoskins B et al (2008) Tibetan Plateau warming and precipitation changes in East Asia. Geophys Res Lett 35:L14702. doi: 10.1029/2008GL034330 CrossRefGoogle Scholar
  30. Wu GX, Liu YM, Yu JJ et al (2008) Modulation of land-sea distribution on air-Sea interaction and formation of subtropical anticyclones. Chin J Atmos Sci (in Chinese) 32(4):720–740Google Scholar
  31. Wu B, Zhou TJ, Li T (2009a) Seasonally evolving dominant inter-annual variability mode over the East Asia. J Clim 22:2992–3005CrossRefGoogle Scholar
  32. Wu ZW, Wang B, Li JP et al (2009b) An empirical seasonal prediction model of the East Asian summer monsoon using ENSO and NAO. J Geophys Res. doi: 10.1029/2009JD011733 Google Scholar
  33. Wu B, Li T, Zhou TJ (2010) Relative contributions of the Indian Ocean and local SST anomalies to the maintenance of the western North Pacific anomalous anticyclone during El Niño decaying summer. J Clim 23:2974–2986CrossRefGoogle Scholar
  34. Xuan SL, Zhang QY, Sun SQ (2011) Anomalous midsummer rainfall in Yangtze River-Huaihe River valleys and its association with the East Asia westerly jet. Adv Atmos Sci 28(2):387–397. doi: 10.1007/s00376-010-0111-3 CrossRefGoogle Scholar
  35. Yang S, Webster PJ (1990) The effect of summer tropical heating on the location and intensity of the extratropical westerly jet streams. J Geophys Res 95:18705–18721CrossRefGoogle Scholar
  36. Ye DZ, Tao SY, Li MC (1958) The catastrophe of general circulation in June and October. Acta Meteorol Sin (in Chinese) 29(4):250–263Google Scholar
  37. Zhang JC (1980) The thermal effect of meridional sea-land distribution on the general atmospheric circulation in Eurasia and its contiguous areas. Acta Meteorol Sin (in Chinese) 38(3):119–226Google Scholar
  38. Zhang YC, Kuang XY, Guo WD et al (2006) Seasonal evolution of the upper tropospheric westerly jet core over East Asia. Geophys Res Lett 33:L11708. doi: 10.1029/2006GL026377 CrossRefGoogle Scholar
  39. Zhou B, Han GR, He JH (2003) Numerical experiment of effects of the upper level westerly jet on a torrential rain over the middle-lower reaches of the Yangtze River. J Nanjing Inst Meteorol (in Chinese) 26(5):595–604Google Scholar
  40. Zhu XJ, Sun JL (2006) Positive feedback of winter ocean-atmosphere interaction in Northwest Pacific. Chin Sci Bull 51(10):2268–2274CrossRefGoogle Scholar
  41. Zhu YL, Wang HJ, Zhou W et al (2010) Recent changes in the summer precipitation pattern in East China and the background circulation. Clim Dyn 36:1463–1473. doi: 10.1007/s00382-010-0852-9 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Climate Dynamics Research Center and Earth System Modeling Center, International Laboratory on Climate and Environment ChangeNanjing University of Information Science and TechnologyNanjingChina
  2. 2.Department of Atmospheric Sciences, International Pacific Research Center, School of Ocean and Earth Science and TechnologyUniversity of Hawaii at ManoaHonoluluUSA
  3. 3.Jiangsu Climate CenterNanjingChina

Personalised recommendations