青藏高原气温序列的均一性研究

Research on the homogeneity of air temperature series over Tibetan Plateau

气象观测资料是气候变化研究的基础,对气象资料进行均一性检验与订正能够提高气候变化研究的精度和准确性.利用青藏高原及周边地区1961-2010年65个气象站的逐月平均气温资料,运用PMFT方法对资料进行均一性检验与订正.结果表明:高原平均气温资料均一性状况较差,有32个站被检测出存在间断点,占总数的49%.用订正后均一的气温数据分析得出,高原1961-2010年年平均气温的升温率为0.32℃·(10a)-1,春、夏、秋、冬季的升温率依次为0.24℃·(10a)-1、0.26℃·(10a)-1、0.32℃·(10a)-1及0.48℃·(10a)-1,略小于用原始数据分析得到的结果.研究还发现,数据均一与否对高原整体气候变化分析结果影响不大,但对局地尺度的气候变化分析结果影响较大.鉴于高原的气候变化具有显著的区域差异性特征,因此,未来在对高原进行气候变化的差异性进行研究时,气象数据均一性的检验与订正工作就显得尤为重要.为提高数据均一性检验的精度,未来应加强气候资料均一性检验技术的研究并尽可能详尽地收集台站的元数据信息.

Meteorological observation data is the basis of climate change research. Detection and correction of homogeneity of meteorological data can improve the precision and accuracy of the climate change research.Based on the monthly mean temperature data from 65 meteorological stations over the Tibetan Plateau and the surrounding areas from 1961-2010,detection and correction of homogeneity of temperature series were carried out by using the PMFT method. The results show that condition of homogeneity of mean air temperature data over the Tibetan Plateau is poor. There are 32 detected stations,accounting for 49% of the total,at least having one breakpoint. The adjusted temperature data is homogeneity. Analyzing the data found that the annual mean temperature had risen with a rate of 0. 32 ℃ ·（ 10a）^-1in the Tibetan Plateau from 1961-2010; the seasonal warming rates over the Tibetan Plateau had been 0. 24,0. 26,0. 32 and 0. 48 ℃ ·（ 10a）^-1for spring,summer,autumn and winter,respectively,slightly smaller than the results obtained by using the original data. The study also found that the data homogeneity or not has little effect on the analysis result of climate change for the plateau as a whole,but has much effect on the result for part of the plateau. Spatially,climate change in the Tibetan Plateau is very different from one area to another area. Therefore,for researching the difference of the climate change over the Tibetan Plateau in the future,detection and correction of homogeneity of meteorological data is particularly necessary. The metadata from meteorological station plays an important role in the process of the climate data homogeneity test and correction,which may provide basical information that affect climate sequence homogeneity,such as the changing site,observation time,method and instrument,and provides reference for analysis,inspection and correction of climate data sequence. In order to improve the accuracy of data homogeneity test,it is necessary to strengthen the study of climate data homogeneity test technique in the future and as far as possible to collect more detail metadata.