Spatial Structure of Ultra-Low-Frequency Variability of the Flow In A Simple Atmospheric Circulation Model
Spatial Structure of Ultra-Low-Frequency Variability of the Flow In A Simple Atmospheric Circulation Model
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简单大气环流模型中气流超低频变化的空间结构
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
P. James
中科院分区：
文献类型：
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作者：
I. N. James;P. James
使用具有中等分辨率的动力过程的多级斜压原始方程模型研究了超过一年的时间尺度上全球环流内部产生的变化。该模型包括理想化的加热和摩擦。最大变化出现在十年左右的时间尺度上。经验正交函数分析表明，这种变化的主要成分是副热带和中纬度急流的交替分裂和合并。发现了涡流活动的强度和分布的相关变化。超低频变化的特征在极低分辨率下完全改变，但在更高分辨率下似乎对模型公式的细节相对不敏感。考虑导出包含超低频变化的低阶模型的可能性。
The internally generated variability of the global circulation on time-scales in excess of one year is investigated using a multilevel baroclinic primitive-equation model with moderate resolution of dynamical processes. the model includes idealized heating and friction. Maximum variability is found on time-scales of around a decade. Empirical orthogonal-function analysis reveals that the principal component of this variability is an alternate splitting and coalescence of the subtropical and mid-latitude jets. Associated changes in the strength and distribution of eddy activity are found. the character of the ultra-low-frequency variability is completely changed for very low resolutions, but seems relatively insensitive to details of model formulation at higher resolution. the possibilities of deriving a low-order model which includes ultra-low-frequency variability are considered.