POEM2模式对热带季节内振荡模拟能力的评估  

DIAGNOSTICS OF THE ABILITY OF POEM2 MODEL IN SIMULATING TROPICAL INTRASEASONAL OSCILLATION

作　　者：王阔[1,2,3] 马浩[1] 李娟[3] 顾伯辉 吴浩[4] 

机构地区：[1]浙江省气候中心,浙江杭州310017 [2]兰州大学大气科学学院,甘肃兰州730000 [3]国际太平洋研究中心,美国夏威夷大学96822 [4]湖南省气候中心,湖南长沙410118

出　　处：《热带气象学报》2016年第3期358-367,共10页Journal of Tropical Meteorology

基　　金：国家自然科学基金(41375078;41175067;41475096);国家重点基础研究发展计划项目(2013CB430204)共同资助

摘　　要：大气季节内振荡与天气和气候系统关系密切，是延伸期数值天气预报研究的重要方面。这种现象在热带地区更为显著，成为衡量气候模式模拟能力的主要指标之一。为了加深数值模式对热带季节内振荡模拟的理解，基于美国夏威夷大学参与研发的POEM2气候系统模式10年回算资料，利用方差分析、功率谱分析等方法对比评估了该模式对热带地区季节内振荡的模拟能力。结果表明，POEM2对850hPa纬向风和OLR方差模拟结果与观测整体分布形势相同，在北印度洋和西太平洋地区模式方差更大。冬季模式模拟MJO东传运动更好，对应对850hPa纬向风的模拟优于夏季。夏季模拟MJO北传运动更好，对应对大气降水的模拟优于冬季。模式模拟MJO信号向东传播速度偏快，气象要素异常功率谱频率大值区主要在2—3波，而观测为1～2波。多变量联合EOF结果表明模式可以模拟出东印度洋和西太平洋高低层风配置和降水的关系，但幅度较弱。POEM2模式前两个EOF模态时间系数时滞相关也呈现与观测类似的周期变化。以上结论表明，未来POEM2气候系统模式需要完善其物理过程和参数化方案，在动力学上加强对混合Rossby重力波的描述，进一步提高对1波的模拟能力。Weather and climate systems are related to Intraseasonal Oscillation （ISO） closely, which is an important aspect for extended range weather forecast. This phenomenon is more significant in tropical regions and becomes one of the indices evaluating climate model simulations. Based on 10 years of hindcast data from PO- EM2 Climate System Model developed by University of Hawaii, we use variance, power spectrum analysis and some other methods to diagnose simulating ability for tropical ISO. Results show that the overall distribution of 850 hPa zonal wind and OLR variance in the POEM2 model is consistent with the observation; the model-simu- lated variances are higher in North Indian Ocean and West Pacific. POEM2 simulates the eastward movement and 850 hPa zonal wind better in winter than in summer, while it simulates the northward movement and precipitation better in summer than in winter. The propagation speed of eastward MJO signal is faster in the model than in the observation, and high frequency spectra of abnormal 850 hPa zonal wind and OLR concentrate in wavenumber 1 - 2 in the observation but in wavenumber 3 - 4 in model simulation. The multivariate combined EOF modes of model shows that POEM2 can simulate the relationship between zonal wind and precipitation in the East Indian Ocean and West Pacific, but it is relatively weak as compared with the observation. The lagging correlation of time series of leading combined EOFs between model and observation also shows a similar cycle. These conclusions suggest that, in the future, POEM2 model needs to improve the interior physical process and parameterization scheme, strengthen the dynamic description of mixed Rossby-gravity modes and improve the simulated ability of wavenumber 1.

关 键 词：气候学 模式评估 功率谱分析 POEM2模式 MJO 

分 类 号：P466[天文地球—大气科学及气象学]