利用向下控制原理对Brewer-Dobson环流变化趋势的研究

 利用ERA-Interim 1979—2011年的逐日数据，通过向下控制原理研究了Brewer-Dobson(BD)环流的季节变化和年际变化.结果表明：对流层剩余环流在15°～30°间为下沉运动，在30°～50°呈上升运动，50°～极地又呈现出下沉运动，且低纬度的上升强度大于中高纬度的上升强度.平流层中环流在30°～45°间下沉，而在45°～60°间又呈上升运动，再在60°～极地间下沉.剩余环流的分布形势具有明显的季节变化特征，冬半球的环流形势要强于夏半球，春秋季期间，环流在两半球呈相对的对称形势.且穿越100hPa面上热带和热带外两半球的质量通量也具有明显的季节变化特征.在过去的33a间平流层BD环流有微弱的增强趋势.
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A study on the trend of the Brewer-Dobson Circulation inlight of the downward control principle

Based on ERA-Interim daily data from 1979 to 2011,downward control principle has been used to study the Brewer-Dobson Circulation (BD).The results show that tropospheric residual circulation descended between 15°and 30°,ascended between 30°and 50°,then again descended poleward of 50°,The rising strength of the low latitude was greater than that of the middle and high latitudes.In stratospheric region the residual circulation descended between 30°and 45°,ascended between 45°and 60°,then again descended poleward of 60°.The results also show that residual circulation has obviously seasonal variation; the circulation pattern in the winter hemisphere is stronger than the summer hemisphere.In spring and autumn,circulation are relatively symmetrically for two hemispheres.And mass flux across the 100hPa pressure surface in tropical and extratropical also has obviously seasonal variation.In addition,it can be concluded that stratospheric BD circulation has been enhanced in the past 33 years.