論气压波和温度波的移动

ON THE DISPLACEMENT OF PRESSURE AND TEMPERATURE WAVES IN A BAROCLINIC ATMOSPHERE

中文摘要:

      利用一个修正的二层模式,作者推导了在均匀基本气流情况下大气中层气压波和其以下平均溫度波的移速公式.其主要結果如下:1)在一般情况下除波数为3-10的波外,溫度波的移动速度大子气压波;2)当地面基本气流为西风时,气压槽接近地势高的地方加速,离开时減速,而气压脊則相反.把这些結果和气压波、溫度波的发生发展联系起来,可以解释一些天气图上出現的現象.作为上述情况的推广,对在不均匀基本气流情况下气压波和溫度波的移速也进行了討論,其主要結果是:1)气压波、溫度波的移速和基本气流的分布有极密切的关系,并主要由后者所决定;2)一般气压波和溫度波在高原北侧比在高原南側移动快,但在它們之間位相差很小而振幅差較大时則有例外.最后,对这些結果和高原以西斜槽、急流沿高原分支、切断低压形成等的联系也作了討論.

英文摘要:

      This paper consists of two parts. First, using a modified、two-layer model, two formulas for evaluating the velocity of pressure waves and that of temperature waves in the case of a uniform basic current, are derived. The main results are as follows: 1. In the general case, the velocity of a temperature wave is greater than that of a pressure wave of same wave length, except for wave number 3 to 10. 2. In the westwind belt, the velocity of a pressure trough is accelerated when it is moving from lowland to highland, and vice versa. For the pressure ridge, the reverse is true. In the second part, a case with a basic current changing with latitude, is discussed. The main results are as follows 1) Both the velocity of pressure waves and that of temperature waves are closely related to and in a large part determined by the distribution of basic current: Roughly speaking, the magnitude of their speeds is proportional to the speed of basic current.averiged with respect to latitude. 2) In the general case, the velocity of a.pressure wave passing through the north of a certain highland, is faster than that of a wave passing through the south of the same highland, except in some special cases. By application of the above results, some synoptic fact, such as the genesis of tilted trough, the splitting of jet stream to the west of Tibet plateau, etc., may be explained reasonably.