摘要
提出了一种风暴轴逐日监测的方法,可以获得逐日的风暴轴变化情况。并且采用了动态阈值定义了新的风暴轴的强度和位置指数,从而可以有效对比不同层次、不同区域、不同时间的风暴轴变化情况。利用NCEP/NCAR再分析资料进行了监测结果的诊断分析。结果表明：各气象要素滤波结果都能表现出两个风暴轴主体,但有位置上的差别。同时可以利用逐日检测的结果求得逐候、逐月的风暴轴监测结果。在不同高度的风暴轴中,250~300 h Pa高度的风暴轴强度最大,850 h Pa有极小值出现,各层风暴轴强度呈现准正压结构。采用500 h Pa高度场风暴轴监测结果做代表,讨论了两大洋上各自的风暴轴偏强/偏弱、偏东/偏西、偏北/偏南时同期大气环流的500 h Pa高度场和300 h Pa纬向风场差异。
A daily monitoring method was proposed to get daily variation of storm track. Moreover,a dynamic threshold was used to indentify the intensity and location index of the new storm tracks in order to compare the storm tracks at different levels,in different areas and at different time effectively. Furthermore,the NCEP / NCAR reanalysis data was used to analyze the monitoring results diagnostically.Results show that all the meteorological elements presented two main bodys of storm tracks,but the differenc in position was quite evident. The pentadly and monthly storm tracks index can be derived from the daily monitoring results. The maximum value of storm tracks＇ intensity existed at 250 h Pa-300 h Pa while the minimum one at 850 h Pa,all of which showed a quasi-barotropic structure. The monitoring results at 500 h Pa geopotential height field were selected to discuss the differences of 500 h Pa height field and300 h Pa zonal wind field of atmospheric circulation when extreme storm tracks process happened.
出处
《气象科学》
北大核心
2015年第3期268-278,共11页
Journal of the Meteorological Sciences
基金
公益性行业(气象)科研专项(GYHY201306028)
国家自然科学基金资助项目(41075070)
关键词
大气环流
风暴轴
遥相关
北大西洋涛动
Atmospheric circulation
Storm tracks
Teleconnection pattern
North Atlantic Oscillation
