摘要
台风系统为中α尺度系统,接近大尺度系统.为了研究环境气流与台风的相互作用,需要将台风从环境风场中分离出来.分别采用时间滤波、空间滤波和动力学方法将2010年第13号(1013号)超强台风"鲶鱼"(Megi)从环境风场中分离出来,对比分离得到的台风环境场,结果表明:时间滤波和空间滤波具有相对的随机性,容易留下台风风场的残留,同时也会减弱环境风场,而采用动力学方法可以将台风"Megi"较好地分离出来.3种方法各有优缺点,采用时间滤波可以使风场、高度场和温度场很好地平衡,但是需要较长的时间序列;空间滤波方法,仅采用一个时刻的时间,方法相对简单易用,但是由于台风风场、高度场和温度场的尺度并不相同,采用同一尺度对台风滤波容易造成风场、高度场和温度场的不平衡;动力学滤波方法分离效果较好,但是相对复杂,在低层也容易产生不平衡的现象.
Typhoon is meso-α scale system and sometimes comparable to large scale system. The isolation of typhoon from the environment flow is an important step in order to investigate the interaction between the environ-ment flow and typhoon circulation.Three methods including time filter,space filter and dynamic method are applied to separate the typhoon Megi （1013） of year 2010 from the environmental flow.The separation results show that, time filter and space filter methods have relative randomness and are somewhat subject to the life cycle and the size of typhoon,which will leave residual typhoon wind to the environmental field,thus weaken the environmental flow;while the dynamic method can well separate the typhoon from the environmental flow.Both advantages and disadvan-tages exist in the three methods.The time filtered wind field is well balanced with other time filtered fields such as temperature and height.While when using space filter,wind may not be consistent with height due to the different scale between wind,height and temperature field.Nevertheless space filter is relatively simple to use and only need one time series,while time filter needs longer time series,which result in no application of time filter in operational forecasting. Dynamic method is better in performance,but relatively complex and sometimes prone to imbalance in lower level and has much space to improve.
出处
《南京信息工程大学学报（自然科学版）》
CAS
2014年第2期152-157,共6页
Journal of Nanjing University of Information Science & Technology（Natural Science Edition）
基金
国家重点基础研究发展计划(973计划)(2013CB430202
2012CB417205)
