地理学报 ›› 2013, Vol. 68 ›› Issue (9): 1269-1280.doi: 10.11821/dlxb201309010

• 气候变化 • 上一篇    下一篇

1961-2010 年西藏极端气温事件的时空变化

杜军1,2, 路红亚2, 建军3   

  1. 1. 中国气象局成都高原气象研究所, 成都 610071;
    2. 西藏自治区气候中心, 拉萨 850001;
    3. 西藏自治区山南地区气象局, 泽当 856000
  • 收稿日期:2013-04-01 修回日期:2013-05-09 出版日期:2013-09-05 发布日期:2013-11-05
  • 作者简介:杜军(1969- ), 男, 贵州绥阳人, 正研高级工程师, 主要从事青藏高原气候变化和农业气候研究。E-mail: dujun0891@163.com
  • 基金资助:
    国家自然科学基金项目(41165011); 中国气象局气候变化专项(CCSF201333)

Variations of extreme air temperature events over Tibet from 1961 to 2010

DU Jun1,2, LU Hongya2, JIAN Jun3   

  1. 1. Institute of Plateau Meteorology, China Meteorological Administration, Chengdu 610071, China;
    2. Tibet Climatic Center, Lhasa 850001, China;
    3. Shannan Meteorological Service of Tibet, Tesdang 856000, Tibet, China
  • Received:2013-04-01 Revised:2013-05-09 Online:2013-09-05 Published:2013-11-05
  • Supported by:
    Foundation National Natural Science Foundation of China, No.41165011; The Research Item of the China Meteorological Administration, No.CCSF201333

摘要: 利用18 个气象站点1961-2010 年逐日最高、最低气温和平均气温资料,分析了西藏极端气温事件的变化规律。结果表明:近50a 西藏霜冻日数和结冰日数明显减少,结冰日数减少显著的区域集中在藏北,霜冻日数则在整个区域都显著减少;生长季长度以4.71 d/10a 的速度明显延长,以拉萨、泽当最显著。极端最低气温在全区范围均呈显著升高,尤其是近30a 升幅更大,达1.06 oC/10a;最高气温的极大值在沿雅鲁藏布江一线东段和那曲地区上升较明显,而在南部边缘地区有下降的趋势。冷夜(昼) 日数普遍明显减少,减幅为9.38 d/10a (4.96 d/10a);暖夜(昼) 日数显著增加,增幅为10.99 d/10a (6.72 d/10a)。大部分极端气温指数的变化趋势与海拔高度有较高的相关性,其中极端最低气温与海拔高度呈正相关,极端最高气温、结冰日数、暖昼(夜) 日数和生长季长度呈负相关。极端最高、最低气温和气温暖指数呈逐年代增加趋势,极端气温冷指数和生长季长度表现为下降的年代际变化特征。在时间转折上,极端最低气温、冷(暖) 夜指数和生长季长度的突变点发生在20 世纪90 年代中期前,霜冻、结冰日数和冷(暖) 昼指数的突变点则推迟到21 世纪初期。多数情况下,西藏极端气温指数的变幅比全国、青藏高原及其周边地区偏大,说明西藏极端气温变化对区域增温的响应更为敏感。

关键词: 趋势, 西藏, 突变, 极端气温指数

Abstract: Based on homogeneity-adjusted daily temperature (maximum, minimum and average) data of 18 stations, spatial and temporal changes of extreme temperature events over Tibet were analyzed for the period 1961-2010. The result shows that the number of frost days and ice days reduced significantly, with the most significant reduction in northern Tibet for ice days, but more extensively across the autonomous region for frost days. The length of growing season (GSL) presented a statistically significant increasing trend at a rate of 4.71 d/ 10a, especially in Lhasa and Zedang. The extra-maximum air temperature (TXx) and extra-minimum air temperature (TNn) generally increased. TXx significantly increased along the east section of the Yarlung Zangbo River and in Nagqu Prefecture, and decreased at the southern edge of Tibet, while TNn significantly increased across the region of Tibet, especially during 1981-2010 with a rate of 1.06oC/10a. Significant reduction at a rate of 9.38 d/10a (4.96 d/10a) occurred on cool nights (days), and significant increase at a rate of 10.99 d/ 10a (6.72 d/10 a) occurred for warm nights (TN90p) (days (TX90p)). There is a close correlation between the trends of most extreme temperature indices and altitude, i.e., positive correlations between altitude and TNn, negative correlations between altitude and TXx, TX90p, TN90p and GSL. In terms of decadal variations, TXx, TNn and other warm indices showed an increasing trend, while the cold indices and GSL decreased. It is also found that the abrupt change points of the TNn, warm (cool) nights and GSL were mainly observed before the mid-1990s, while frost days, ice days and warm (cool) days occurred in the early 2000s. In most cases, the linear trend magnitudes of extreme air temperature indices in Tibet were larger than those in the whole country, Tibetan Plateau and its surrounding areas (Qinghai Province, Hengduan Mountains), which show that the extreme air temperature indices response are more sensitive to the regional warming.

Key words: linear trend, climate abrupt change, extreme temperature indices, Tibet