瞬时经圈环流与西风带环流变化的关系

ON THE RELATION BETWEEN THE MID LATITUDE MERIDIONAL CELL AND THE CHANGE OF ZONAL CIRCULATION

中文摘要:

      用一九七六年冬半年八个个例,对纬圈平均非热成风,瞬时经圈环流和西风带环流变化的关系进行了个例分析和统计分析。指出。当纬圈平均非热成风产生率(∂u'_T/∂t)为较大的负值时,出现逆瞬时经圈环流,并有利于长波的阻尼和纬向环流的维持或加强;反之,当∂u'_T/∂t为正值时,出现正瞬时经圈环流,并有利于长波的发展和纬向环流的减弱或崩溃。对于上述关系,本文还从物理上进行了初步的讨论。

英文摘要:

      The relation between the zonal averaged non-thermal wind, the instantaneous mean meridional cell and the change of zonal circulation is investigated synoptitally and statistically for eight cases which are selected from the winter half year of 1916-77.Preliminary results are obtained. When the rate of change of zonal averaged non-thermal wind, denoted by (∂u'_T/∂t), is a large negative value there exists an indirect meridional circulation in middle latitudes. Under such situation, planetary waves tend to decay and zonal circulation tends to intensify. In contrast, when (∂u'_T/∂t) is a positive, there exists a direct meridional cell Under this condition, planetary waves will develop and zonal circulation decreases. Finally, the above results are discussed by making use of the conception of adjustment of thermal wind.