中国近50 a地温的变化特征

利用1954-2001年中国532站的月平均0．8m层地温资料，对我国及其不同区域地温的变化特征进行了分析。结果表明，近50a，全国年平均地温的年代际变化大致为下降阶段，相对气候冷期及上升阶段。地温的区域变化特征显著，90年代后东北地区地温增温最显著，西南东部地区地温下降趋势明显，青藏高原东部地温在1980年前后发生一次急剧下降的突变过程。地温季节变化中，冬季地温年代际变化特征与其他季节相比差异较显著，而春季地温年际变化出现异常的频率最大。

Characteristics of Soil Temperature Variations in China in Recent 50 Years

Based on the data of monthly mean soil temperature at the depth of 0.8 m at 532 stations in 1954-2001 ,the characteristics of the soil temperature variation in six sub-regions in China are analyzed. The results indicate that in the recent 50 years, the annual mean soil temperature successively experienced a cooling period, a relative cold period and then a warming period. In Northeast China, soil temperature has remarkably increased after 1990s, while in the eastern part of Southwest China, soil temperature exhibited an evident decreasing tend. Around 1980, the eastern part of the Tibetan Plateau experienced a climatic jump featured with a dramatic decrease of soil temperature. In every sub-region, the interdecadal variation of soil temperature in winter differs obviously from those of other seasons, while the interannual variation of soil temperature in spring is most distinctive.