Southern Hemisphere Planetary-scale Waves and Blocking

[摘要] The importance of stationary and travelling planetary-scale waves for southen hemisphere blocking has been investigated. The data used are 500-mb geopotential height data from nine winter seasons. The first three zonal harmonics of these data were decomposed in a low-pass filtered quasi-stationary part, and a travelling part being the difference between the unfiltered and filtered values.The behaviour of the planetary-scale waves during periods with blocked flow is documented. It is found that unlike blocking in the northern hemisphere there is no systematic behaviour of the ultra-long waves during southern hemisphere blocking.

[学科分类] 大气科学