Dynamical Processes Related to the Appearance of Quasi-Stationary Waves on the Subtropical Jet in the Midsummer Northern Hemisphere
Dynamical Processes Related to the Appearance of Quasi-Stationary Waves on the Subtropical Jet in the Midsummer Northern Hemisphere
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DOI：
10.1175/jcli3697.1
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发表时间：
2006-04
影响因子：
4.9
通讯作者：
N. Sato;M. Takahashi
中科院分区：
文献类型：
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作者：
N. Sato;M. Takahashi
利用客观分析资料和卫星资料，研究了北方半球盛夏副热带急流准定常行星波的统计特征。其结果是，一个准定常波列，是高度相关的盛夏气候在日本被确定。一个明确的相位依赖性的波的外观也得到了证实。时间演变和波活动通量的分析表明，波包的东向传播始于中东，经过东亚，到达北美。在中东亚洲急流入口附近，通过动能转换，异常型得到加强。异常斑图与基本场的相互作用导致了异常波状斑图的出现。虽然波列与西北太平洋和印度洋对流活动的异常相关，但这意味着内部动力在确定副热带急流上出现异常准定常波的统计特征方面是重要的。
Statistical features of quasi-stationary planetary waves were examined on the subtropical jet in the midsummer Northern Hemisphere by using objectively analyzed data and satellite data. As a result, a quasi-stationary wave train that is highly correlated with the midsummer climate over Japan was identified. A clear phase dependency of the appearance of waves was also confirmed. An analysis of temporal evolution and wave activity flux revealed that the eastward propagation of the wave packet starts in the Middle East, passes over East Asia, and reaches North America. The anomaly pattern is strengthened through kinetic energy conversion near the entrance of the Asian jet over the Middle East. The interaction between the anomaly pattern and the basic field contributes to the appearance of the anomalous wavelike pattern. Although the wave train is correlated with the anomaly of convective activity over the western North Pacific and the Indian Ocean, it is implied that internal dynamics are important in determining the statistical features of the appearance of anomalous quasi-stationary waves on the subtropical jet.