四种客观定量表征阻塞高压方法的对比分析

已有的阻塞高压客观定量化表征方法可归纳为距平方法、 T&M方法、 动力学方法和环流型方法四种。以2008年1月1日~2月2日中国持续性低温雨雪冰冻灾害期间的阻塞高压事件为例， 利用NCEP/NCAR逐日再分析等压面资料， 检验对比了上述四种方法的优点与缺点。结果表明， 每种方法都有其优点和局限性， 表明仅以某种标准或公式的客观方法实现对多种形态的阻塞高压的精确识别是极其困难的。同时还指出， 研究者和业务技术人员在了解各种阻塞高压客观表征方法的优、 缺点基础上， 针对具体需求选取适合的方法， 也可以结合实际情况予以改进， 都将可能获得更好的应用效果。

Comparison and Analysis among Four Objective and Quantificational Blocking Indexes

Existing objective, quantificational blocking indexes can be summed up by four: Departure method, T&M method, PV-θ index and circumfluent type method. Taking blocking highs in durative weather disaster including low temperature, snowfall and freezing in China from January 1 to February 2, 2008 as an instance, the merits and demerits of these four objective means are researched one by one according to the daily reanalysis data provided by NCEP/NCAR. The results are as follows: Every method has its merits and ineluctable demerits because of algebra operational conformation for objective blocking index. These reflect that it′s difficult to identify blocking accurately in some sense created by earth′s atmosphere with its almost infinite degrees of freedom. Based on what merits and demerits of these blocking indexes have, investigator and operation department could apply blocking indexes better if they select compatible one or improve and innovate a method according to their selves practice.