The El Niño-Southern Oscillation cycle simulated by the climate system model of Chinese Academy of Sciences
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摘要: 基于中国科学院气候系统模式200年的模拟结果, 评估了该模式对ENSO循环的模拟能力, 包括ENSO的发生、发展和衰减过程. 结果表明, 模式能模拟出热带太平洋海表温度的季节和年际变化以及ENSO的季节锁相. 此外, 模式还抓住了El Niño爆发的两个先决条件, 即赤道西太平洋的西风异常和偏暖的海表温度. 由于外热带经向风强迫偏强, 模式中西风异常偏强, 加之模式中温跃层偏浅、倾斜程度偏弱, 西太平洋暖海表温度异常东传速度偏快, 导致El Niño发展偏快. 在衰减阶段, 由于模式中El Niño偏强, 热带大气对东太平洋变暖的二次Gill型响应也偏强, 导致西太平洋出现持续的东风异常. 与此同时, Ekman抽吸抬升了西太平洋的温跃层, 暖池出现冷异常, 二者共同作用导致了El Niño衰减为La Niña. 模式中ENSO周期偏短、振幅偏大, 这与赤道太平洋温跃层偏浅有关, 温跃层偏浅将导致上层海洋中热量的再分配加速完成.Abstract: On the basis of more than 200-year control run, the performance of the climate system model of Chinese Academy of Sciences (CAS-ESM-C) in simulating the El Niño-Southern Oscillation (ENSO) cycle is evaluated, including the onset, development and decay of the ENSO. It is shown that, the model can reasonably simulate the annual cycle and interannual variability of sea surface temperature (SST) in the tropical Pacific, as well as the seasonal phase-locking of the ENSO. The model also captures two prerequisites for the El Niño onset, i.e., a westerly anomaly and a warm SST anomaly in the equatorial western Pacific. Owing to too strong forcing from an extratropical meridional wind, however, the westerly anomaly in this region is largely overestimated. Moreover, the simulated thermocline is much shallower with a weaker slope. As a result, the warm SST anomaly from the western Pacific propagates eastward more quickly, leading to a faster development of an El Niño. during the decay stage, owing to a stronger El Niño in the model, the secondary Gill-type response of the tropical atmosphere to the eastern Pacific warming is much stronger, thereby resulting in a persistent easterly anomaly in the western Pacific. Meanwhile, a cold anomaly in the warm pool appears as a result of a lifted thermocline via Ekman pumping. Finally, an El Niño decays into a La Niña through their interactions. In addition, the shorter period and larger amplitude of the ENSO in the model can be attributed to a shallower thermocline in the equatorial Pacific, which speeds up the zonal redistribution of a heat content in the upper ocean.
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Key words:
- climate system model of Chinese Academy of Sciences /
- El Niñ /
- o-Southern Oscillation cycle /
- El Niñ /
- o /
- thermocline
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AchutaRao K, Sperber K R. 2006. ENSO simulation in coupled ocean atmosphere models: are the current models better? Climate dyn, 27(1): 1-15 An S I, Jin F F. 2004. Nonlinearity and asymmetry of ENSO. J Climate, 17(12): 2399-2412 Bellenger H, Guilyardi E, Leloup J, et al. 2014. ENSO representation in climate models: from CMIP3 to CMIP5. Climate dyn, 42(7-8): 1999-2018 Bjerknes J. 1969. Atmospheric teleconnections from the equatorial Pacific. Mon Wea Rev, 97(3): 163-172 Briegleb B P, Bitz C M, Hunke E C, et al. 2004. Scientific description of the sea ice component in the community climate system model, version three. NCAR Technical Note NCAR/TN-463+STR, Colorado: National Center for Atmospheric Research, doi: 10.5065/d6HH6H1P. Carton J A, Chepurin G, Cao X, et al. 2000. A simple ocean data assimilation analysis of the global upper ocean 1950-1995, Part 1: methodology. J Phys Oceanogr, 30(2): 294-309 dickinson R E, Oleson K W, Bonan G, et al. 2006. The community land model and its climate statistics as a component of the community climate system model. J Climate, 19(11): 2302-2324 Fedorov A V, Philander S G. 2001. A stability analysis of tropical ocean-atmosphere interactions: Bridging measurements and theory for El Niño. J Climate, 14(14): 3086-3101 Guilyardi E. 2006. El Niño-mean state-seasonal cycle interactions in a multi-model ensemble. Climate dyn, 26(4): 329-348 Guilyardi E, Wittenberg A, Fedorov A, et al. 2009. Understanding El Niño in ocean-atmosphere general circulation models: progress and challenges. Bull Amer Meteor Soc, 90(3): 325-340 Ingleby B, Huddleston M. 2007. Quality control of ocean temperature and salinity profiles-Historical and real-time data. J Marine Syst, 65(1-4): 158-175 Jin F F. 1997. An equatorial ocean recharge paradigm for ENSO. Part I: Conceptual model. J Atmos Sci, 54(7): 811-829 Kanamitsu M, Ebisuzaki W, Woollen J, et al. 2002. NCEP-dOE AMIP-II reanalysis (R-2). Bull Amer Meteor Soc, 83(11): 1631-1643 Larkin N K, Harrison d E. 2002. ENSO warm (El Niño) and cold (La Niña) event life cycles: Ocean surface anomaly patterns, their symmetries, asymmetries, and implications. J Climate, 15(10): 1118-1140 Latif M, Sperber K, Arblaster J, et al. 2001. ENSIP: the El Niño simulation intercomparison project. Climate dyn, 18(3-4): 255-276 Leloup J, Lengaigne M, Boulanger J P. 2008. Twentieth century ENSO characteristics in the IPCC database. Climate dyn, 30(2-3): 277-291 Li Chongyin, Mu Mingquan. 1999. El Niño occurrence and sub-surface ocean temperature anomalies in the Pacific warm pool. Chinese Journal of Atmospheric Sciences (in Chinese), 23(5): 513-521 Liebmann B, Smith C A. 1996. description of a complete (interpolated) outgoing longwave radiation dataset. Bull Amer Meteor Soc, 77: 1275-1277 Liu Changzheng, Xue Feng. 2008. The persistent maintenance of the strong westerly anomalies over the equatorial western Pacific during the onset and development of ENSO. Climatic and Environmental Research (in Chinese), 13(2): 161-170 Liu Changzheng, Xue Feng. 2010a. The decay of El Niño with different intensity. Part I, The decay of the strong El Niño. Chinese Journal of Geophysics, 53(1): 14-25 Liu Changzheng, Xue Feng. 2010b. The decay of El Niño with different intensity. Part II, The decay of the moderate and relatively-weak El Niño. Chinese Journal of Geophysics, 53(6): 915-925 Liu Changzheng, Xue Feng. 2012. The abortion of El Niño event in 1993 and its comparison with the typical El Niño event. Climatic and Environmental Research (in Chinese), 17(2): 197-204 Liu Hailong, Yu Yongqiang, Li Wei, et al. 2004. Manual for LASG/IAP Climate System Ocean Model (LICOM1.0) (in Chinese). Beijing: Science Press, 107 Philander S G H. 1983. El Niño and Southern Oscillation phenomena. Nature, 302(5906): 295-301 Philander S G H. 1985. El Niño and La Niña. J Atmos Sci, 42(23): 2652-2662 Philander S G H, Fedorov A. 2003. Is El Nino sporadic or cyclic? Annu Rev Earth Planet Sci, 31: 579-594 Picaut J, Masia F, du Penhoat Y. 1997. An advective-reflective conceptual model for the oscillatory nature of the ENSO. Science, 277(5326): 663-666 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 Rayner N A, Parker d E, Horton E B, et al. 2003. Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J Geophys Res, 108(d14): doi: 10.1029/2002Jd002670 Suarez M J, Schopf P S. 1988. A delayed action oscillator for ENSO. J Atmos Sci, 45(21): 3283-3287 Sun Hongchuan, Zhou Guangqing, Zeng Qingcun. 2012. Assessments of the climate system model (CAS-ESM-C) using IAP AGCM4 as its atmospheric component. Chinese Journal of Atmospheric Sciences (in Chinese), 36(2): 215-233 Trenberth K E. 1997. The definition of El Niño. Bull Amer Meteor Soc, 78(12): 2771-2777 Weisberg R H, Wang Chunzai. 1997. A western Pacific oscillator paradigm for the El Niño-Southern Oscillation. Geophys Res Lett, 24(7): 779-782 Wu Bo, Li Tim, Zhou Tianjun. 2010. Asymmetry of atmospheric circulation anomalies over the western north Pacific between El Niño and La Niña. J Climate, 23(18): 4807-4822 Wyrtki K. 1975. El Niño-The dynamic response of the Equatorial Pacific Ocean to atmospheric forcing. J Phys Oceanogr, 5(4): 572-584 Xue Feng, He Juanxiong. 2007. The influence of the extratropical atmospheric disturbances on ENSO. Chinese Journal of Geophysics, 50(5): 1130-1138 Xue Feng, Liu Changzheng. 2008. The influence of moderate ENSO on summer rainfall in eastern China and its comparison with strong ENSO. Chinese Science Bulletin, 53 (5): 791-800 Yu J Y, Kim S T. 2010. Identification of central-Pacific and eastern-Pacific types of ENSO in CMIP3 models. Geophys Res Lett, L15705, doi: 10.1029/2010GL044082 Zebiak S E, Cane M A. 1987. A model El Niño-Southern Oscillation. Mon Wea Rev, 115(10): 2262-2278 Zhang He. 2009. development of IAP atmospheric general circulation model version 4.0 and its climate simulations [dissertation]. Beijing: University of Chinese Academy of Sciences, 194 Zhou Guangqing, Li Chongyin. 1999. Simulation on the relation between the subsurface temperature anomaly in western Pacific and ENSO by using CGCM. Climatic and Environmental Research (in Chinese), 4(4): 346-352 Zhou Guangqing, Zeng Qingcun, Zhang Ronghua. 1999. An improved air-sea coupled model and its numerical simulation. Progress in Natural Science (in Chinese), 9(6): 542-551
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