海气耦合对MJO数值模拟的影响  

Impact of Air–Sea Coupling on MJO Simulation

作　　者：赵雨晴 凌健[1,2] ZHAO Yuqing;LING Jian(State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,Chinese Academy of Science,Beijing 100029;University of Chinese Academy of Science,Beijing 100049)

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029 [2]中国科学院大学,北京100049

出　　处：《气候与环境研究》2020年第4期353-365,共13页Climatic and Environmental Research

基　　金：中国科学院前沿科学重点研究项目QYZDB-SSW-DQC017;国家重点基础研究发展计划项目2015CB453200;国家自然科学基金项目41575062、41520104008。

摘　　要：采用一种基于降水异常追踪MJO(Madden–Julian Oscillation)东传的MJO识别方法(MJO Tracking)评估了参与MJOTF/GASS(MJO Task Force/Global Energy and Water Cycle Experiment Atmospheric System Study)全球模式比较计划的全海气耦合模式(CNRM-CM)、半海气耦合模式(CNRM-ACM)和大气模式(CNRMAM)1991~2010年模拟MJO的能力,探究了海气耦合过程对模式模拟MJO能力的影响机理。CNRM-CM模式模拟的MJO结构更加接近观测,该模式不仅具有最高的MJO生成频率,也能够模拟较强的MJO强度以及较远的传播距离。海气耦合过程会造成CNRM-CM和CNRM-ACM模式中印度洋—太平洋暖池区域海温气候态的冷偏差。但是这种海温气候态的偏差基本没有改变模式模拟MJO的能力。CNRM-CM中MJO对流中心东(西)侧存在较强的季节内尺度海温暖(冷)异常,纬向梯度明显,而CNRM-ACM和CNRM-AM中不存在这样的海温东西不对称结构。结果表明在CNRM模式中海气耦合过程调控模式海温季节内尺度变率对模式MJO模拟能力的影响比调控模式海温气候态更加重要。The MJO(Madden–Julian Oscillation)simulation ability of the numerical experiments from CNRM GCMs(General Circulation Models)participated in the MJOTF/GASS(MJO Task Force/Global Energy and Water Cycle Experiment Atmospheric System Study)project was evaluated by tracking the eastward propagating positive equatorial precipitation anomalies.The GCMs included a fully coupled simulation(CNRM-CM),a half-coupled simulation(CNRM-ACM),and an uncoupled simulation(CNRM-AM)based on 1991–2010 data.The possible impacts of air–sea coupling on the MJO simulation were investigated.The CNRM-CM showed the highest ability in simulating the MJO characteristics,in terms of the occurrence frequency,amplitude,and propagation range.The climatological sea surface temperature(SST)of the CNRM-CM and CNRM-ACM showed a distinct cold bias over the Indo–Pacific warm pool region,compared with that of the CNRM-AM.The cold bias did not strongly impact the MJO simulation ability compared with the impacts on the MJO simulation abilities of the CNRM-ACM and CNRM-AM.The zonal gradient of the intraseasonal SST was significant in the CNRM-CM,with a strong positive intraseasonal SST anomaly to the east of the MJO convection center and a negative intraseasonal SST anomaly to the west of the MJO convection center when the MJO was over the Indian Ocean.In contrast,such a gradient was lost in the CNRM-ACM and CNRM-AM.The results indicate that the impact of the air–sea coupling on the MJO simulations by the CNRM GCMs was mainly through the influences on the intraseasonal SST variability.

关 键 词：热带大气季节内振荡 模式模拟 海气耦合 海表面温度 

分 类 号：P444[天文地球—大气科学及气象学]