摘要
本文用1980年11月16日至1981年3月16日共4个月的资料,分析了冷空气活动关键区和影响区的各物理量的变化规律,发现存在明显的单周和准40天活动的振荡周期,冷空气的活动与这两种周期振荡有密切关系,其中强冷空气的活动主要受准40天周期振荡控制。关键区对流层底层温度场的准40天振荡位相比影响区(华中地区)提前约5天左右,其振幅大小也较好地反映了冷空气的强弱,为预报强冷空气活动提供了参考条件。另外,强冷空气在向南传播过程中的不同阶段可能具有不同的传播特征。最后讨论了低纬高空东风气流的加强西伸与强冷空气活动的联系。
In this paper, characteristics of variation in different physical elements in the key area and affected areas of the cold activities in East Asia during winter are, studied. Significant one-week and quasi-40-day oscillations are observed, which have close relation to the cold air activities. It is found that the strong cold air activity is mainly under the control of the low frequency oscillation. The phase of the quasi-40-day oscillation of temperature in the key area is about 5 days earlier than that in the affected areas (central China) and its amplitude responds quite well to the strength of cold air.This provides a good reference for the forecasting of cold air. Besides, the cold air may show different characteristics at different stages of its southward propagation. In the end, the relation between the intensification and westward extension of the upper easterly jet in the lower latitudes in East Asia and the strong cold air activities is discussed.
出处
《南京气象学院学报》
CSCD
1990年第3期339-347,共9页
Journal of Nanjing Institute of Meteorology
基金
国家自然科学基金(编号 4870263)
