气候变暖前后我国热度日和冷度日的特征分析

Analysis of Heating/Cooling Degree Days in China under Background of Climate Warming

基于全国1960—2011年气象台站的逐日资料,运用度日分析法、Mann-Kendall检验法研究了气候变暖前后我国热度日(HDD)、冷度日(CDD)的变化情况。结果表明,我国北方及高原地区冬季气温在1987年前后发生突变,气候变暖后HDD有所下降;我国南方夏季气温在1997年前后发生突变,气候变暖后CDD有所上升。利用NCEP/NCAR再分析资料和环流指数资料进一步分析气候变暖前后的环流场特征,发现冬季AO指数与我国东北、华北、新疆西藏部分地区HDD具有显著的负相关关系,AO指数偏强(弱)时,强冷空气活动减少(增加),HDD减小(增大);夏季西太平洋副高面积指数与我国南方地区CDD具有显著的正相关关系,副高面积指数偏强(弱)时,晴热高温天气增加(减少),CDD增大(减小)。

Based on the observed data from 1960 to 2011,the Heating Degree Days（HDD）and Cooling Degree Days（CDD）in China are calculated and analyzed by using the Mann-Kendall test.The results show that an abrupt change of winter temperature in the northern China and its adjacent plateau region occurred at around 1987,along with the decreasing HDD on the background of climate warming.The summer temperature in the southern China changed abruptly around 1997,with CDD increasing after that.The circulation characteristics before and after the climate warming are further analyzed by using the NCEP/NCAR reanalysis data and the circulation index data.It is found that the Arctic Oscillation（AO）index is negatively correlated with HDD in the northern China and its adjacent plateau region.When the AO index is stronger（weaker）than normal,the heavy cold air events decrease（increase）,along with the decreasing（increasing） HDD.On the other hand,the Subtropical High Area（SHA）index has a significantly positive correlation with CDD in southern China.When the SHA index is stronger（weaker）than normal,the fair weather with high temperature will increase（decrease）,along with the increasing（decreasing）CDD.