【作者】 陆晓波；

【导师】 徐海明； 何金海；

【作者基本信息】 南京信息工程大学 ， 气象学， 2006， 硕士

【摘要】 本文利用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50年,全国年平均地温的年代际变化特征大致可分为下降阶段,相对气候冷期及上升阶段。地温的区域变化特征显著,东北地区地温90年代后增温最显著,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它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。 同时,还利用1961～2000年695站的月平均0cm地温和气温的资料计算了各测站的地气温差,分析了地气温差的时空分布特征及其与夏季西太平洋副高强度和位置的关系,并通过定义春季地气温差的指数(IDGA),研究了IDGA与同期大气环流异常及其夏季降水和夏季风强弱年代际变化的相互关系。结果表明:(1)我国地气温差场除冬季北方地区出现负值外,春、夏、秋三季均为正值。不同季节之间地气温差异常的空间分布型差异显著。(2)夏季西太平洋副高指数与3月至6月的地气温差场存在正负偶极子型相关分布,即我国中纬度地区东西向的地气温差呈相反的变化趋势。(3)春季地气温差的指数(IDGA)存在明显的年代际变化,并与同期大气环流异常之间存在对应关系。(4)春季IDGA指数与长江中游、内蒙东部及新疆东部等地的夏季降水存在显著正相关,且IDGA指数的年代际变化特征与夏季风环流强弱的年代际变化相对应。更多还原

【Abstract】 Based on the data of monthly mean soil temperature in the depth of 0.8m from 532 stations in 1954-2001, the characteristics of the soil temperature variation over different areas in China are analyzed. The results indicate that in recent 50 years, the annual mean soil temperature experienced a cooling period, a relative cold period and a warming period. In Northeast China, soil temperature obviously increases after 1990s, while in the eastern part of Southwest China, soil temperature exhibits decreasing tendency. In around 1980, the eastern part of the Tibetan Plateau experienced a climatic jump that is featured by the decrease of soil temperature. In every area, Soil temperature interdecadal variation in winter is different from other seasons, while interannual variation in spring is the most obvious.Meantime, the data of monthly mean ground temperature in the depth of 0cm and air temperature from 695 stations in 1961-2000 are used to calculate the differences between ground temperature and air temperature (DGAT). The distribution of the DGAT in space-time and the correlation between the DGAT and the intensity and location of subtropical high in the western Pacific are analyzed. Then, the index of the DGAT in spring is defined and the relations between the index and the atmospheric circulation anomaly in the same term and the precipitation in summer and the summer monsoon interdecadal variation are analyzed. The results show that firstly, the value of the DGAT is positive all over the country except for the DGAT in Northeast China in winter and there are the different space-time distributions of the DGAT in different seasons. Secondly, the correlated distribution of the positive-negative dipole between the DGAT from March to June and the area of subtropical high in the western Pacific indicates the reverse trend of the zone differences of the DGAT. Thirdly, the interdecadal variation of the index of the DGAT is obvious and there is a corresponding correlation between the index and the atmospheric circulation anomaly in the same term. Fourthly, the positive correlations between the index and the summer precipitation in the middle and lower of the Yangtse Rive, the eastern of the Inner Mongolia and the SinKiang are evident. The interdecadal variation of the index of the DGAT corresponds to the summer monsoon interdecadal variation.更多还原