环太湖地区气候变化特征研究

根据1971—2010年环太湖地区苏州、常州、长兴等9个气象台站日平均气温和日降水量资料,采用EOF正交经验分析法、线性倾向率法、小波分析法和Mann-Kendall检验法研究了环太湖地区近40 a来的气候变化特征。结果表明:1) 1971—2010年间,环太湖地区整体上呈增暖趋势,环太湖地区的季节性增暖存在空间差异,西北部的气温在春、夏季明显升高,而东南部则在秋、冬季明显增暖,1990年前后该地区的增暖率存在完全相反的空间分布。2)该40 a中,降水表现为北部增加,南部减少。整个环太湖地区的降水在冬季普遍呈现增加趋势,春、夏季降水的空间分布差异性大于秋、冬季。3) M orlet小波分析结果表明,环太湖地区年平均温度存在16～17 a和6 a、26 a左右的变化周期;年降水量存在15～16 a和24 a的强显著性变化周期,各地区在年均温、年降水量周期振荡的强度上存在一定的差异。4) Mann-Kendall突变检验显示,1971—2010年环太湖地区各站点均表现为气温由低向高的突变,突变发生在1992—1993年。

Patterns and characteristics of climate changes around the Taihu Lake area

The area around the Taihu Lake is quick and sensitive in response to climate elements changes,such as temperature and precipitation with regard to complex and variable climate,special geographical location and landform morphology.Therefore the study in this area is profound and significant for explaining the local special climate changes and laying the foundations for the research about the impact of urbanization on the climate changes around the Taihu Lake area in the future.Based on the daily mean temperature and daily precipitation data of 9 meteorological stations around the Taihu Lake area from 1971 to 2010,the methods of linear regression,EOF analysis,Morlet wavelets analysis and Mann-Kendall Test were used in this paper to analyze the spatial and temporal pattern and characteristics of climate changes.The results are as follows:(1)During the period 1971-2010,the air temperature around the Taihu Lake area has been increasing in general,and the precipitation distribution had an increasing tendency in the northern part of the area and a reducing tendency in the southern part.There is a spatial difference of seasonal heating rate in the area around the Taihu lake area,the air temperature in the northwest area increased significantly in spring and summer,while there was a significantly heating rate in autumn and winter in the southeast area.Besides,there was a completely opposite spatial-distribution in heating rate around the year of 1990.In the whole area the precipitation was increasing generally in winter,the spatial precipitation distribution differs widely in spring and summer.(2)The annual mean temperature fluctuated significantly with an interval of 16 years or 17 years,and fluctuated with the intervals of 6 years and 26 years in the small scale of the whole area around the Taihu Lake area.The annual precipitation in the area fluctuated significantly with interval of 15 years or 16 years and 24 years.Whereas,there were some differences in intensity of the annual mean temperature fluctuation and the annual precipitation fluctuation in terms of different regions.(3)During the period 1992-1993,there was an abrupt climate change from low temperature to high temperature for all stations in this area.