基于Γ分布的气压序列非均一性检验方法初探

The Inhomogeneity Test Method of Atmospheric Pressure Sequences Based on Γ-distribution

通过对安徽省内23个代表台站1961—2006年平均气压序列均一性检验的研究,提出了一种基于Γ分布气压序列非均一性检验方法——Γ检验法。以桐城市数据为例,给出了检验和分析的具体过程,最后将该方法检验结果与常见的基于正态分布的SNHT法检验结果进行了对比分析,结果表明:该方法具有更广泛的使用范围和较高的准确性,可以检验大部分年平均气压的非均一性。检验结果表明:气压计高度的调整、台站迁址是安徽省内气压序列非均一性的主要原因。

Climate change research is built on the basis of homogeneity sequence data which can reflect the real changes. Therefore the homogeneity and/or the inhomogeneity of the meteorological observation data should be tested before using the data for climate change research. Currently, the main methods of homogeneity test are based on the hypothesis that the data sequences obey the normal distribution. However, in Anhui Province, it is found the average pressure sequence homogeneity test for 23 representative stations from 1961 to 2006 that some sequences are not subject to normal distribution, which can not be tested by the common method based on normal distribution. At the same time, it is found that some sequences obey Г-distribution （pass the significant level of 0.05 Kolmogorov goodness-of-fit tests）. A new homogeneity test method, Г-test, for atmospheric pressure sequences is presented, in which the hypothesis should be met at first that the sequence is subject to Г-distribution. Firstly, some reference stations are used to construct a reference sequence; then the ration sequences of stations which will be the test sequences to reference sequences are gotten; thirdly, the ration sequences are tested by Г-test sequence homogeneity test; finally, the cause of the inhomogeneity sequences are analyzed by checking the history of the stations. The method is briefly introduced, and the data of Tongcheng are taken as an example, the concrete process of Г-testing and analysis are given. Furthermore, the result of Г-test is compared with SNHT which is a wideIy use method. The results show that the 23 stations can be tested by Г-test and the accuracy rate reaches 78.3 %. In contrast, four stations can not be tested by SNHT and the accuracy only reaches 53.8%. In other words, Г- test is superior to SNHT in scope and accuracy. Nevertheless, Г-test also has some problems such as the high computational complexity and missing of some change points. The Homogeneity test results show that the change of barometer height and the station location is the main reason of the significant inhomogeneity of atmospheric pressure sequences in Anhui Province.