作　　者： (曲姝霖）; (仝纪龙）; (唐睿）; (李佳芸）;

机构地区： 兰州大学大气科学学院,甘肃兰州730107

出　　处： 《气象与环境学报》 2017年第4期78-85,共8页

摘　　要： 利用国家气候中心整编的中国西北地区日最高气温的观测资料,通过对中国西北地区极端高温变化特征进行较全面的分析,揭示了近20 a(1996—2015年)与近55 a(1961—2015年)中国西北地区极端气温变化的新特征。结果表明:除新疆维吾尔自治区部分和陕西省南部部分地区外,1961—2015年西北地区极端高温事件出现频次普遍呈增加的趋势,大值中心集中分布在新疆维吾尔自治区东南部、青海省北部、甘肃省西部和宁夏回族自治区中部地区,线性增加率为3.00次/10 a以上,其中大部地区增加趋势通过了99.5%以上信度的显著性检验,与全球气候变暖的特征较为一致。近20 a来西北地区极端高温事件出现频次呈西部和南部地区增多、东部和北部地区减少的空间变化特征。近20 a西北地区极端高温事件出现频率呈"西南部地区多、北部和东部地区少"的变化趋势,与前20 a(1961—1980年)极端高温事件出现频次的变化趋势相近,与近30 a(1981—2010年)极端高温事件出现频率的"西南部地区少、中东部地区多"的变化趋势相反。近55 a西北地区极端高温事件平均出现频次呈增加的趋势,平均值为1.73次/10 a;主要阶段变化率分别为:前20 a极端高温事件平均出现频次为0.06次/10 a,近30 a极端高温事件平均出现频次为3.90次/10 a,近20 a极端高温事件平均出现频次为-0.46次/10 a。近20 a西北地区极端高温事件出现频次呈弱递减的趋势与全球1998年以后增温的停滞现象较一致,说明西北地区的区域极端高温事件减少的特征对全球气候变暖停滞现象存在响应。由西北地区极端高温事件出现频次异常偏多年和偏少年的典型温度场可知,西北地区夏季异常高温变化对印度洋和太平洋的海温变化具有明显的正响应。西北地区极端最高气温和极端高温事件的温度强度分布主要取决于海拔高度,其次与局地地形和下垫面性� Based on the daily maximum temperature data from the National Meteorological Information Center,the characteristics of extremely high temperature in Northwest China were analyzed in order to reveal some new fea-tures in extreme temperature in recent 20 （ from 1996 to 2015 ） and 55 years （ from 1961 to 2015 ） . The results show that except the southern parts of Xinjiang Uygur Autonomous region and Shaanxi province,the frequency of extremely high-temperature events in Northwest China generally increases from 1961 to 2015 . The high number of extreme event is mainly located in the southeastern Xinjiang Uygur Autonomous region,northern Qinghai prov-ince,western GanSu province,and central Ningxia province,with a linearly increasing number of extreme event more than 3. 00 per decade. Most of them pass 99. 5% or more significant tests. This is consistent with the charac-teristics of global warming. For the last 20 years （from 1996 to 2015）,the frequency of extremely high-tempera-ture events increases in the west and south parts,and reduces in the east and north parts. This is consistent with that in the previous 20 years （1961-1980）,but opposite to that in nearly 30 years （from 1981 to 2010） . In the past 55 years,the average number of extremely high-temperature events in Northwest China is on the rise with 1. 73 per decade,and that in the previous 20,nearly 30,and the last 20 years rises 0. 06,3. 90 and-0. 46 per decade,respec-tively. The decreasing trend in the number of extremely high-temperature events in the last 20 years is consistent with the stagnation status of global warming occurring after 1998 . It suggests that this decreasing trend is a kind of responses to the stagnation of global warming. Based on the typical temperature field analysis,it indicates that the abnormal variation in high temperature in Northwest China has a significant response to the change in sea surface temperature in the Indian Ocean and the Pacific Ocean. The distributions of temperature intensity both in extreme max

关 键 词： 西北地区 极端高温 气候变暖 停滞 海拔高度