陈秋士,林本达. 1965. 北半球冬季副热带高压带维持的涡度机制[J]. 气象学报, 37(3):364-370, doi:10.11676/qxxb1965.042
北半球冬季副热带高压带维持的涡度机制
THE VORTICITY BUDGET OF THE ZONE OF SUBTROPICAL HIGHS IN NORTHERN HEMISPHERE FOR WINTER
投稿时间:1964-06-21  
DOI:10.11676/qxxb1965.042
中文关键词:  
英文关键词:
基金项目:
作者单位
陈秋士 北京大学地球物理系 
林本达 北京大学地球物理系 
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中文摘要:
      本文利用涡度平衡方程讨论北半球冬季副热带高压的维持,计算发现,30°N副热带高压带地区,大型扰动所造成的涡度输送的辐散是维持这地区反气旋涡度的主要因子,这种辐散作用所造成的反气旋涡度主要发生在对流层上层,平均经圈环流对地转祸度的输送可以把它引导到对流层下层来。此外,我们还根据涡度输送的计算,讨论了西风急流的维持。向北的扰动涡度输送在45°N上空达极大值,因此它对中纬度西风和纬向平均急流的维持起着重要作用。但30°N上空,扰动的涡度输送为零,而平均经圈环流对地转涡度和相对涡度的输送都比较大,因此,可以认为副热带急流是在平均经圈环流作用下维持的。
英文摘要:
      In this paper, the maintenance of the sub-tropical high in northern hemisphere for winter is discussed by means of the balance equation of the vorticity. The calculated results show that the divergence of the vorticity transfer due to the large-scale eddies is the dominant factor for maintainning anticyclonic vorticity in the region near 30°N. The anticyclonic vorticity due to this divergence process occurs mainly in the upper troposphere; at the same time, the transfer of earth rotation vorticity may effect the anticyclonic vorticity downward to the lower troposphere. The maintenance of the westerly jet is also discussed from the view-point of the vorticity transfer. The northward vorticity transfer by the large-scale eddies reaches its maximum value over 45°N, so that it may play an important role both for the maintenance of the mean zonal westerlies and its jet in the middle latitude. Over 30°N, however, the vorticity transfer by large scale eddies vanishes, and on the contrary, both the transfer of earth rotation vorticity and of the relative vorticity have larger value. Thus, it may be considered that the subtropical jet is maintained by the mean mcridional circulation.
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