摘要
用中国科学院大气物理研究所发展的一个大气环流模式,使用不同的积云参数化方案和分辨率进行了6个模拟试验,考察了积云参数化方案和模式分辨率对热带大气季节内振荡(MJO)模拟的影响。结果显示:积云参数化方案和分辨率都会影响MJO的模拟。但积云参数化方案决定了模式对MJO模拟的基本能力,决定了模拟的MJO的基本特征。分辨率的变化并不能使模拟的MJO发生本质的改变,分辨率的作用更多的是对MJO的模拟起一定的调制作用,而这种调制作用又受到积云参数化方案的制约。在改进积云参数化方案的基础上提高模式的分辨率会在某些方面改善MJO的模拟。但是分辨率的提高需要同时提高水平分辨率和垂直分辨率,单独提高水平分辨率会降低模式模拟MJO的能力,引入更多的小尺度的高频扰动。非绝热加热垂直廓线对模式模拟MJO有重要的影响,而非绝热加热廓线很大程度上取决于所使用的积云参数化方案。模式水平分辨率的变化不会对加热廓线的结构产生明显的影响,而垂直分辨率的变化会对加热廓线的垂直结构产生一定的调制作用,进而对模拟的MJO起到调制作用。
To investigate their impacts on the MJO simulation, Madden Julian Oscillations are examined in six integrations using an AGCM developed at the Laboratory for Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics（LASG） of Institute of Atmospheric Physics（IAP） of Chinese Academy of sciences with different cumulus parameterization schemes and different resolutions. Results suggest that both resolutions and cumulus parameterizations can impact the MJO simulation, but the cumulus parameterization is more crucial than the resolution, which determines the most fundamental ability of the AGCM in simulating the MJO, whereas, impacts of resolution on the MJO simulation are depended on the cumulus parameterization. Only if the cumulus parameterization scheme in an AGCM simulates eastward propagating intraseasonal signals, can the resolution increase further to improve the MJO simulation. Increasing the horizontal resolution alone is likely to introduce high frequency noises into simulated MJO. Thereby, the vertical resolution needs to be increased simultaneously. The vertical profile of diabatic heating may be a factor that is responsible for these different modeling results. Among the six integrations, three that well simulate the MJO also produce similar heating profile with heating peak near the middle-troposphere. In contrast, the diabatic heating produced by the other three is very weak and nearly uniform with height in vertical. Meanwhile, the three integrations also fail to simulate reasonable MJO features. The vertical profile of diabatic heating is determined by cumulus parameterization scheme to a large extent.
出处
《热带气象学报》
CSCD
北大核心
2009年第1期1-12,共12页
Journal of Tropical Meteorology
基金
国家自然科学基金(40575027
40675051)
中科院创新项目(KZCX3-sw-226)共同资助
关键词
MJO
数值模拟
积云参数化
分辨率
非绝热加热廓线
Madden Julian Oscillation
AGCM
cumulus parameterizations
resolution
adiabatic heating profile
