The Vertical Structure of the Stratospheric Sudden Warming
The Vertical Structure of the Stratospheric Sudden Warming
复制标题
平流层突然变暖的垂直结构
DOI：
10.2151/jmsj1965.45.5_422
复制
发表时间：
1967
期刊：
影响因子：
--
通讯作者：
I. Hirota
中科院分区：
文献类型：
--
作者：
I. Hirota
The vertical structure of the stratospheric temperature field and its time variations were analyzed throughout the period of the sudden warming phenomenon by use of the daily synoptic weather maps published by Free University of Berlin. The sudden warming in January 1963, which was observed over southeastern Canada, was the chief study with further analyses of the sudden warmings of January 1958 and March 1965. The vertical cross sections of temperature and its time variations were shown along the western semi-circle at 50*N in the five levels from 300 mb up to 10 mb. It is found from these analyses that the vertical trough line is strongly tilted westward above the 50 mb level with increasing height, where isotherms are nearly parallel to the tilted trough line, and this disturbance, as a whole, moves westward (or northwestward) when the warming reaches its maximum. As the result of the westward movement of the tilted axis, the vertical time-section at one station shows that the warming first occurred in the upper level and moved downward. On the contrary, vertical cross sections of the time change of temperature show that the warming appears first at the 100 mb or 50 mb level and then it propagates upward with a phase speed of about 10 mb/day. The upward propagation of the warming is also verified by the vertical cross sections along longitude 50*W from the North pole to 20*N. Thus the sudden warming phenomenon is considered to consist of two stages, i, e., the intensification stage in which the disturbance propagates upward from lower to the upper stratosphere, and the migratory stage in which it moves westward in connection with the breakdown of the polar vortex. These features of the warming phenomenon are common at least to these three cases.
