近40年气候变化及其空间分异的多尺度研究——以内蒙古自治区为例

利用小波变换对内蒙古27个气象台站40年(1956~1995)的年平均气温和降水数据进行多尺度分析,结果表明,1956~1958是40年中最冷的年份,20世纪60年代初和90年代初是两个主要的气温升高和降水增加时期。在大时间尺度上,气温和降水基本处于相对高值,气温有逐渐增加趋势,部分气象台站的降水有减少趋势;中小尺度上气温和降水变化具有更多的表现形式,体现在气温冷暖变化和降水多少变化的频率和强度上。内蒙古气温变化的空间分布格局具有明显的沿纬度分布的特征,降水变化基本上体现了一种沿经度分布的空间格局。对内蒙古3~5月气候干湿状况研究表明,20世纪50年代末和80年代初是两个相对湿润时期,1994年后气候最为干燥,大时间尺度存在非常明显的气候由湿润到干燥的变化趋势;中小尺度上干湿状况变化较频繁。

Multiscale Studies on Climatic Change and It's Spatial Heterogeneity in Recent 40 Years:a Case Study in Inner Mongolia

After analyzing average annual temperature and precipitation of the 27 meteorological stations in Inner Mongolia from 1956 to 1995 using wavelets transformation, the authors draw following conclusions. (1) The coldest period was from 1956-1958 and there were two main accretion periods of both air temperature and precipitation at the beginning of the 1960s and 1990s. Observed from large scale of time, i.e. between 36 years and 40 years, both air temperature and precipitation were in the state of relatively high values. Meanwhile, temperature had an increasing trend while some meteorological stations' precipitation was gradually decreasing. On the moderate scale and small scale of time, i.e., between 16 years and 20 years and between 4 years and 8 years, air temperature and precipitation both had more varying forms embodied in their changing frequency and fluctuation intensity. (2) Based on multiscale characters of air temperature and precipitation respectively, the authors use some numeric numbers to describe those characters and sort the meteorological stations as four types. This paper shows the spatial patterns of air temperature and precipitation change using the ordinary Kriging interpolating method. The spatial pattern of air temperature change of Inner Mongolia has the trend of varying with latitude while the spatial pattern of precipitation change has the rough trend of varying with longitude. (3) In the end, the dry-humid features from March to May of Inner Mongolia are studied in this article that include two humid periods happened at the end of the 1950s and in 1980-1982 and a driest period happened after 1994. On the large scale, a clear trend of turning from humidity to dryness can be detected. On the moderate scale and small scale, the change between humidity and dryness are relatively frequent.