摘要
利用西藏自治区38个气象站点1981-2014年逐日02：00、08：00、14：00和20：00北京时4个时次气温数据，采用线性回归、Mann．Kendall非参数检验等方法，分析了近34年来西藏时次气温变化的时空分布、突变特征，并探讨了气温变化率与经纬度、海拔高度之间的关系。结果表明：近34年西藏四季各时次气温表现一致的升高趋势，升温率为0．14-0．80℃／10a，以冬季升温最为显著。在各时次中，除夏季08时升温率大之外，其他三季均以14时升温率最大。各站年时次气温最大升温率为0．36～0．94℃／10a（P〈0．001），只有32％的站点出现在08时，主要分布在昌都市大部、阿里地区大部以及那曲、拉萨、日喀则等站点，其余站点都出现在14时。春、秋季时次气温升温率与经度有关，西部大于东部；冬季时次气温升温最大区域主要在高海拔和纬度较高地区，夏季气温升幅最大区域位于较高纬度。20世纪80年代四季和年各时次气温均为负距平，而21世纪最初的10年各时次气温一年四季都为正距平。在时间转折上，34年来西藏年、季绝大部分时次的气温都发生了气候突变，夏季4个时次气温突变时间都发生在21世纪最初的10年；冬季02时和08时气温突变点发生20世纪90年代末，14时和20时气温的突变点却出现在21世纪最初的10年。影响西藏高原气温变化的因素有很多，主要包括地形、高原内部气象要素以及外部环流影响等。
Based on 6-hourly （02：00, 08：00, 14：00 and 20：00 Bejing time （BJT）） air temperature data of 38 meteorological stations over Tibet from 1981 to 2014, the spatial- temporal distribution and climate abrupt characteristics of air temperature are analyzed by using the methods including linear regression and Mann-Kendall test. Also, the correlation between the change rates of surface air temperature and latitude （longitude, and altitude） is discussed. The results showed that, the seasonal air temperature in Tibet exhibits unanimously increasing trend with a rate of 0.14-0.80 %/10a during the past 34 years, and the most significant increase occurred in winter. In terms of the rate per decade for the 6-hourly air temperature observations, 08：00 BJT during summer experienced the highest increasing rate, while 14：00 BJT showed the highest values for the other three seasons. The maximum rate for the increasing air temperature ranges from 0.36 ℃/10a （P 〈 0.001） to 0.94 ℃/10a （P 〈 0.001）. Among all the 38 stations, there were only 32% （about 12） showing the peak time with the highest rate of changes at 08：00 BJT air temperature, which are predominantly located in much of Qamdo, Ngari prefecture and at weather stations such as Nagqu, Lhasa and Xigaze, while the rest of weather stations showed the highest increasing rate at 14：00 BJT. In spring and autumn, as the increasing rate was related to longitude, it has a larger rate in western than that in eastern Tibet. In winter, the highest increasing rate of air temperature occurred in the regions with higher altitudes and latitudes, and the higher increasing rate of air temperature was observed at higher latitudes in summer. As for the decadal characteristics of 6-hourly air temperature, the 1980s experienced negative anomalies, compared with positive anomalies in the first decade of the 21st century. Additionally, it was found with abrupt change test that at the annual and seasonal scales most of hourly air temperatures have abrupt
出处
《地理学报》
EI
CSCD
北大核心
2016年第3期422-432,共11页
Acta Geographica Sinica
基金
国家科技部公益性行业科研专项(GYHY201306029)
中国气象局气候变化专项(CCSF201333)~~
关键词
时次气温
变化趋势
时空分布
西藏
6-hourly air temperature
linear trend
climate abrupt change
Tibet
