摘要
利用第五次和第六次国际间耦合模式比较计划(CMIP)中piControl情景下的模拟结果,结合观测资料,对比评估了19个CMIP5模式和23个CMIP6模式对太平洋年代际振荡(PDO)调制厄尔尼诺-南方涛动事件爆发频率不对称的模拟能力,并进一步揭示了PDO的调制过程。结果表明:在观测中,PDO正(负)位相下厄尔尼诺(El Niño)的爆发频率比拉尼娜(La Niña)多300%(少73%),53%(78%)的CMIP5(6)模式模拟出这一特征;尽管两个模式整体都低(高)估了PDO正(负)位相的调制能力,但CMIP6模式对PDO调制能力的模拟有所改进。进一步研究发现,在PDO正(负)位相下,赤道太平洋中西部会产生较强的西(东)风异常,风场通过平流的作用使得暖水向东流动,从而在太平洋中东部的海表面温度背景场中出现正(负)异常变化,而这有利于PDO正(负)位相下El Niño(La Niña)事件的发生。
Based on the observations and the simulation outputs under piControl scenario from the phase 5 and phase 6 of the Coupled Model Intercomparison Projects(CMIP),this study compares and evaluates the simulation ability of 19 CMIP5 models and 23 CMIP6 models on the El Niño-Southern Oscillation frequency asymmetry modulated by Pacific Decadal Oscillation(PDO),and further reveals the modulation process of PDO.The results show that the frequency of El Niño is 300%higher by 300%(lower by 73%)than that of La Niña in the positive(negative)phase of PDO.53%(78%)of CMIP5(6)models can simulate this feature.Although CMIP5/6 models underestimate(overestimate)the modulation ability of PDO in the positive(negative)phase,the simulation performance of CMIP6 on the modulation ability of PDO is improved compared with CMIP5 models.Further work shows that in the positive(negative)phase of PDO,a strong west(east)wind anomaly will occur in the central and western equatorial Pacific.Wind drives the warm water flow eastward through horizontal advection,thus a positive(negative)anomaly of sea surface temperature will occur in the central and eastern equatorial Pacific,which promotes the occurrence of El Niño(La Niña)event under the positive(negative)phase of PDO.
作者
胡伟
陈权亮
林壬萍
陈幸荣
HU Wei;CHEN Quanliang;LIN Renping;CHEN Xingrong(Chengdu University of Information Technology,Chengdu 610225,China;Center for Earth System Modeling and Prediction of CMA,Beijing 100081,China;National Marine Environmental Forecasting Center,Beijing 100081,China)
出处
《海洋预报》
CSCD
北大核心
2023年第3期104-113,共10页
Marine Forecasts
基金
国家自然科学基金面上项目(42175045)。
