Cite this paper:
HU Haibo, WU Qigang, WU Zepeng. Influences of two types of El Niño event on the Northwest Pacific and tropical Indian Ocean SST anomalies[J]. HaiyangYuHuZhao, 2018, 36(1): 33-47

Influences of two types of El Niño event on the Northwest Pacific and tropical Indian Ocean SST anomalies

HU Haibo1,2, WU Qigang1, WU Zepeng1,3
1 CMA-NJU Joint Laboratory for Climate Prediction Studies, Instituted for Climate and Global Change Research, School of Atmospheric Science, Nanjing University, Nanjing 210093, China;
2 Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing 210044, China;
3 Meteorology Center of Middle South Regional Air Traffic Management Bureau of Civil Aviation of China, Guangzhou 510406, China
Abstract:
Based on the HadISST1 and NCEP datasets, we investigated the influences of the central Pacific El Niño event (CP-EL) and eastern Pacific El Niño event (EP-EL) on the Sea Surface Temperature (SST) anomalies of the Tropical Indian Ocean. Considering the remote effect of Indian Ocean warming, we also discussed the anticyclone anomalies over the Northwest Pacific, which is very important for the South China precipitation and East Asian climate. Results show that during the El Niño developing year of EP-EL, cold SST anomalies appear and intensify in the east of tropical Indian Ocean. At the end of that autumn, all the cold SST anomaly events lead to the Indian Ocean Dipole (IOD) events. Basin uniform warm SST anomalies exist in the Indian Ocean in the whole summer of EL decaying year for both CP-and EP-ELs. However, considering the statistical significance, more significant warm SST anomalies only appear in the North Indian Ocean among the June and August of EP-EL decaying year. For further research, EP-EL accompany with Indian Ocean Basin Warming (EPI-EL) and CP El Niño accompany with Indian Ocean Basin Warming (CPI-EL) events are classified. With the remote effects of Indian Ocean SST anomalies, the EPI-and CPI-ELs contribute quite differently to the Northwest Pacific. For the EPI-EL developing year, large-scale warm SST anomalies arise in the North Indian Ocean in May, and persist to the autumn of the El Niño decaying year. However, for the CPI-EL, weak warm SST anomalies in the North Indian Ocean maintain to the El Niño decaying spring. Because of these different SST anomalies in the North Indian Ocean, distinct zonal SST gradient, atmospheric anticyclone and precipitation anomalies emerge over the Northwest Pacific in the El Niño decaying years. Specifically, the large-scale North Indian Ocean warm SST anomalies during the EPI-EL decaying years, can persist to summer and force anomalous updrafts and rainfall over the North Indian Ocean. The atmospheric heating caused by this precipitation anomaly emulates atmospheric Kelvin waves accompanied by low level easterly anomalies over the Northwest Pacific. As a result, a zonal SST gradient with a warm anomaly in the west and a cold anomaly in the east of Northwest Pacific is generated locally. Furthermore, the atmospheric anticyclone and precipitation anomalies over the Northwest Pacific are strengthened again in the decaying summer of EPI-EL. Affected by the local WindEvaporation-SST (WES) positive feedback, the suppressed East Asian summer rainfall then persists to the late autumn during EPI-EL decaying year, which is much longer than that of CPI-EL.
Key words:    EPI-EL|CPI-EL|Indian Ocean SST anomalies|zonal SST gradient in the Northwest Pacific|Northwest Pacific anticyclone anomaly|East Asian Summer rainfall   
Received: 2016-11-04   Revised: 2016-12-20
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Articles by WU Qigang
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References:
Annamalai H, Murtugudde R, Potemra J et al. 2003. Coupled dynamics over the Indian Ocean:Spring initiation of the zonal mode. Deep Sea Res. Part Ⅱ Top Stud Oceanogr., 50(12-13):2 305-2 330.
Annamalai H, Xie S P, McCreary J P et al. 2005. Impact of indian ocean sea surface temperature on developing El Niño. J. Climate, 18(2):302-319.
Ashok K, Behera S K, Rao S A et al. 2007. El Niño modoki and its possible teleconnection. J. Geophys. Res., 112(C11):C11007.
Choi J, An S I, Yeh S W et al. 2012. ENSO-like and ENSOinduced tropical Pacific decadal variability in CGCMs. J. Climate, 26(5):1 485-1 501.
Du Y, Xie S P, Huang G et al. 2009. Role of air-sea interaction in the long persistence of El Niño-induced North Indian Ocean warming. J. Climate, 22(8):2 023-2 038.
Du Y, Yang L, Xie S P. 2011. Tropical Indian ocean influence on northwest pacific tropical cyclones in summer following strong El Niño. J. Climate, 24(1):315-322.
Fan L, Shin S I, Liu Q Y et al. 2013. Relative importance of tropical SST anomalies in forcing East Asian summer monsoon circulation. Geophys. Res. Lett., 40(10):2 471-2 477.
Feng J, Chen W, Tam C Y et al. 2011. Different impacts of El Niño and El Niño modoki on China rainfall in the decaying phases. Int. J. Climatol., 31(14):2 091-2 101.
Feng J, Li J P. 2011. Influence of El Niño modoki on spring rainfall over south China. J. Geophys. Res., 116(D13):D13102.
Feng J, Wang L, Chen W et al. 2010. Different impacts of two types of Pacific Ocean warming on southeast Asian rainfall during boreal winter. J. Geophys. Res., 115(D24):D24122.
Fu C B, Fletcher J. 1985. Two types of tropical warming event during EL Niño. Chinese Science Bulletin, 31(8):38-41.
Guo F Y, Liu Q Y, Sun S et al. 2015. Three types of Indian Ocean dipoles. J. Climate, 28(8):3 073-3 092.
Hu H B, He J, Wu Q G, Zhang Y. 2011. The Indian Ocean's asymmetric effect on the coupling of the Northwest Pacific SST and anticyclone anomalies during its springsummer transition after El Niño. J. Oceanogr., 67(3):315-321.
Hu H B, Hong X Y, Zhang Y et al. 2013a. The critical role of Indian summer monsoon on the remote forcing between Indian and Northwest Pacific during El Niño decaying year. Sci. China Earth Sci., 56(3):408-417.
Hu H B, Hong X Y, Zhang Y et al. 2013b. Remote forcing of Indian Ocean warming on Northwest Pacific during El Niño decaying years:a FOAM model approach. Chin. J.
Oceanol. Limnol., 31(6):1 375-1 383, https://doi.org/10.1007/s00343-013-3075-1.
Huang G, Hu K M, Xie S P. 2010. Strengthening of tropical Indian Ocean teleconnection to the Northwest Pacific since the Mid-1970s:an atmospheric GCM study. J. Climate, 23(19):5 294-5 304.
Kao H Y, Yu J Y. 2009. Contrasting eastern-pacific and centralpacific types of El Niño. J. Climate, 22(3):615-632.
Klein S A, Soden B J, Lau N C. 1999. Remote sea surface temperature variations during ENSO:evidence for a tropical atmospheric bridge. J. Climate, 12(4):917-932.
Kug J S, Jin F F, An S I. 2009. Two types of El Niño events:cold tongue El Niño and warm pool El Niño. J. Climate, 22(6):1 499-1 515.
Larkin N K, Harrison D E. 2005. On the definition of El Niño and associated seasonal average U.S. weather anomalies. Geophys. Res. Lett., 32(13):L13705.
McPhaden M J, Busalacchi A J, Cheney R et al. 1998. The tropical ocean-global atmosphere observing system:a decade of progress. J. Geophys. Res., 103(C7):14 169-14 240.
McPhaden M J, Lee T, McClurg D. 2011. El Niño and its relationship to changing background conditions in the tropical Pacific Ocean. Geophys. Res. Lett., 38(15):L15709.
Murtugudde R, McCreary J P Jr, Busalacchi A J. 2000. Oceanic processes associated with anomalous events in the Indian Ocean with relevance to 1997-1998. J. Geophys. Res., 105(C2):3 295-3 306.
Nagura M, Konda M. 2007. The seasonal development of an SST anomaly in the Indian Ocean and its relationship to ENSO. J. Climate, 20(1):38-52.
Peng J B, Zhang Q Y, Chen L T. 2011. Connections between different types of El Niño and Southern/Northern Oscillation. Acta Meteor. Sinica, 25(4):506-516.
Rasmusson E M, Carpenter T H. 1982. Variations in tropical sea surface temperature and surface wind fields associated with the Southern Oscillation/El Niño. Mon. Wea. Rev., 110(5):354-384.
Ren H L, Jin F F. 2011. Niño indices for two types of ENSO. Geophys Res Lett, 38(4):L04704.
Rong X Y, Zhang R H, Li T. 2010. Impacts of Atlantic sea surface temperature anomalies on Indo-East Asian summer monsoon-ENSO relationship. Chin. Sci. Bull., 55(22):2 458-2 468.
Roxy M, Gualdi S, Drbohlav H K L et al. 2011. Seasonality in the relationship between El Niño and Indian Ocean dipole. Climate Dyn., 37(1-2):221-236.
Saji N H, Goswami B N, Vinayachandran P N et al. 1999. A dipole mode in the tropical Indian Ocean. Nature, 401(6751):360-363.
Tan Y K, Zhang R H, He J H et al. 2004. Relationship of the interannual variations of sea surface temperature in tropical Indian ocean to ENSO. Acta Meteorologica Sinica, 62(6):831-840. (in Chinese)
Trenberth K E, Tepaniak D P. 2001. Indices of El Niño Evolution. J Climate, 14(8):1 697-1 701.
Wallace J M, Rasmusson E M, Mitchell T P et al. 1998. On the structure and evolution of ENSO-related climate variability in the tropical Pacific:lessons from TOGA. J. Geophys. Res., 103(C7):14 241-14 259.
Wang B, Wu R G, Fu X H. 2000. Pacific-East Asian teleconnection:how does ENSO affect East Asian climate?. J. Climate, 13(9):1 517-1 536.
Wang C Z, Wang X. 2013a. Classifying El Niño modoki I and Ⅱ by different impacts on rainfall in southern China and typhoon tracks. J. Climate, 26(4):1 322-1 338.
Wang X, Wang C Z. 2013b. Different impacts of various El Niño events on the Indian Ocean Dipole. Climate Dyn., 42(3-4):991-1 005.
Wang X, Zhou W, Li C Y et al. 2014. Comparison of the impact of two types of El Niño on tropical cyclone genesis over the South China Sea. Int. J. Climatol., 34(8):2 651-2 660, doi:10.1002/joc.3865.
Weng H Y, Ashok K, Behera S K et al. 2007. Impacts of recent El Niño modoki on dry/wet conditions in the Pacific Rim during boreal summer. Climate Dyn., 29(2-3):113-129.
Weng H Y, Wu G X, Liu Y M et al. 2011. Anomalous summer climate in China influenced by the tropical Indo-Pacific Oceans. Climate Dyn., 36(3-4):769-782.
Wu B, Tim L, Zhou T J. 2010. Relative contributions of the Indian Ocean and local SST anomalies to the maintenance of the Western North Pacific anomalous anticyclone during the El Niño decaying summer. J. Climate, 23(11):2 974-2 986.
Wu G X, Meng W. 1998. Gearing between the Indo-monsoon circulation and the Pacific-Walker circulation and the ENSO. Part I:data analyses. Chinese Journal of Atmospheric Sciences, 24(1):15-25. (in Chinese)
Wu R G, Kirtman B P. 2004. Understanding the impacts of the Indian Ocean on ENSO variability in a coupled GCM. J. Climate, 17(20):4 019-4 031.
Xiang B, Wang B, Ding Q et al. 2012. Reduction of the thermocline feedback associated with mean SST bias in ENSO simulation. Climate Dynamics, 39(6):1 413-1 430.
Xiao Y, Zhang Z Q, He J H. 2009. Progresses in the studies on Indian ocean dipoles. Journal of Tropical Meteorology, 25(5):621-627. (in Chinese)
Xie S P, Hu K M, Hafner J et al. 2009. Indian ocean capacitor effect on indo-western Pacific Climate during the Summer following El Niño. J. Climate, 22(3):730-747.
Xie S P, Philander S G H. 1994. A coupled ocean-atmosphere model of relevance to the ITCZ in the Eastern Pacific. Tellus A, 46(4):340-350.
Xu K, Zhu C W, He J H. 2012. Linkage between the dominant modes in Pacific subsurface ocean temperature and the two type ENSO events. Chin. Sci. Bull., 57(26):3 491-3 496.
Yang J L, Liu Q Y, Xie S P et al. 2007. Impact of the Indian Ocean SST basin mode on the Asian summer monsoon. Geophys. Res. Lett., 34(2):L02708.
Yeh S W, Kug J S, Dewitte B et al. 2009. El Niño in a changing climate. Nature, 461(7263):511-514.
Yu J Y, Kao H Y. 2007. Decadal changes of ENSO persistence barrier in SST and ocean heat content indices:1958-2001. J. Geophys. Res., 112(D13):D13106.
Yu J Y, Kim S T. 2011. Relationships between extratropical sea level pressure variations and the central Pacific and eastern Pacific types of ENSO. J. Climate, 24(3):708-720.
Yuan Y, Yan H M. 2013. Different types of La Niña events and different responses of the tropical atmosphere. Chin. Sci. Bull., 58(3):406-415.
Yuan Y, Yang S, Zhang Z Q. 2012. Different evolutions of the philippine sea anticyclone between the eastern and central Pacific El Niño:possible effects of Indian ocean SST. J. Climate, 25(22):7 867-7 883.
Yuan Y, Yang S. 2012. Impacts of different types of El Niño on the East Asian climate:focus on ENSO cycles. J. Climate, 25(21):7 702-7 722.
Zhang R H. 1999. The role of Indian summer Monsoon water vapor transportation on the summer rainfall anomalies in the northern part of China during the El Niño mature phase. Plateau Meterology, 18(4):567-574. (in Chinese)
Zhang W J, Jin F F, Li J P et al. 2011. Contrasting impacts of two-type El Niño over the western north Pacific during Boreal Autumn. J. Meteor. Soc. Japan, 89(5):563-569.
Zhao S S, Yang X Q. 2004. Numerical experiments on interaction between the tropical Pacific and the Indian Ocean through the wind-stress "bridge". Acta Oceanologica Sinica, 26(4):33-48. (in Chinese)