应用转折点与游程的气候分析与预报  

AN APPLICATION OF TURNING POINTS AND RUNS TO CLIMATIC ANALYSIS AND PREDITION

作　　者：么枕生[1] 

机构地区：[1]南京大学大气科学系

出　　处：《地理研究》1986年第3期1-11,共11页Geographical Research

摘　　要：本文把游程和转折点结合起来,研究不同游程转折点和不同游程所组成的转折周期,以游程转折点作为持久循环事件加以推导和用于气候分析或预报。In this paper, flood/drought runs combined with tunaing points were called flood/drought run-turning points. Consider the flood/drought run-turning points in the historical flood/drought records of the last 500 years as recurrent events.Then, the theory of recurrent events may be applied to the historical records for climatic analysis. Now, let F be flood year with probabilityP, while D the drought year with probability q. If e+ = FFF--FD,then thecri-tical point between F and D is called the positive run-turning point, while the critical point between D and F is called the negative run-turning point, ife' = DDD--DF. Let fn(+)=p (e+occurs for the first time at thenth trial) andfn(-)=p (e-occurs for the first time at thenth trial) for n>1 with f0(+) =0. Then, mean and variance of the run-turning times were derived by means of generating function, and the calculated results of these parameters at different stations are likely useful in climatic analysis.Convolution of the sequences { fn(-)} and { f (+) } is { fn* } = { fn(-)}* { fn(+)}, where f* = p (turning period or flood-drought period e* occurs for the firsttime at the n th trial) . In accordance with definition of the convolution, we have found that f * = pq (qn -1-pn-1/q - p) . Mean and variance of theturning period constituted by combination of the flood-run and drought run are 1/pq and p3+q3/P2q2 respectively.Though the time series of annual records is nearly a purely random process, the intercorrelation in the time series of run-lengths combined positive run-lengths with negative run-lengths is sufficiently high. Therefore, the author suggested that the run AR models obtained from AR models of run-lengths could be used to predict the flood/drought runs, and it was concluded that the climatic analysis might be performed by the same models as well.

关 键 词：转折周期 长期预报 分析与预报 时间序列 折点 年降水量 随机循环 预报方程 气候预报 预报准确率 

分 类 号：P9[天文地球—自然地理学]