CMIP5/6气候模式对ElNiño多样性模拟能力的评估

Assessment of El Niño diversity simulations using CMIP6 and CMIP5 models

利用第五次和第六次国际间耦合模式比较计划(coupled model intercomparison project,CMIP)中全球气候模式的历史时期和未来增暖情景模拟结果,结合观测资料,文章对比评估了23个CMIP6模式和32个CMIP5模式对El Niño多样性的模拟能力,并预估了东部(eastern Pacific,EP)型和中部(central Pacific,CP)型El Niño对未来全球变暖的响应特征。结果表明,绝大多数CMIP5/6气候模式能够合理地模拟El Niño的多样性特征,且CMIP6多模式的模拟性能较CMIP5有明显提升。CMIP6模式不仅减弱了EP型El Niño空间模态模拟的离散性,而且还显著提高了CP型El Niño空间模态的模拟能力;CMIP5/6多模式基本能够模拟出两类El Niño的季节锁相性特征,但CP型El Niño衰亡时间较观测明显滞后3个月;同时CMIP5/6多模式模拟的EP型El Niño强度与观测值较为接近,但CP型El Niño的振幅却强于观测。在未来全球变暖背景下,CP型El Niño事件的发生频率相对于EP型事件将趋于降低;EP型和CP型El Niño振幅强度随着全球变暖加剧将被增强,且EP型增强幅度显著强于CP型。

Based on the observations and the global climate model simulation outputs of historical run and future warming scenarios from phase 5 and phase 6 of the coupled model intercomparison project(CMIP),we assessed the performance of 23 CMIP6 and 32 CMIP5 models in reproducing El Niño diversity,and then projected the responses of the eastern Pacific(EP)and central Pacific(CP)type of El Niño to global warming.The results show that most CMIP5/6 models can reasonably simulate the characteristics of El Niño diversity,and the simulation performance of CMIP6 models is significantly improved compared with CMIP5 models.Not only do the CMIP6 models weaken the discreteness of the simulated EP El Niño-related spatial patterns,but also significantly improve the simulation ability of the CP El Niño-associated spatial patterns.The CMIP5/6 models can basically simulate the seasonal phaselocking characteristics of the EP and CP El Niño events,however,compared to the observation,the decay time of the simulated CP El Niño is obviously delayed by 3 months.The intensity of EP El Niño simulated by CMIP5/6 is close to the observation,but the counterpart of CP El Niño is stronger than the observation.Under global warming,the frequency of CP El Niño will tend to decrease relative to EP El Niño.The amplitudes of EP and CP El Niño will be enhanced along with the intensification of global warming,and the enhanced amplitude of EP El Niño is greatly stronger than that of CP El Niño.