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投稿时间:2009-03-26 修订日期:2010-04-12
投稿时间:2009-03-26 修订日期:2010-04-12
中文摘要: 系统地研究了1961—2008年三峡库区不同极端高温指标(包括极值、绝对阈值和相对阈值指标)变化规律及其与区域性增暖的关系,并分析了三峡库区夏季高温干旱异常年的环流形势。结果表明:近48年三峡库区各极端高温指数年代际变化与该区域年平均气温有较好的一致性,20世纪80年代中前期之前为下降趋势,之后转为上升趋势。逐年代变化上均表现为80年代偏低,其他年代均偏高。相对阈值指标(HWDI、WSDI和TX90p)在偏高/低年份、线性趋势、相关系数上都与年平均气温表现出较其他指数更好的一致性。相关分析表明极值指标与绝对阈值指标之间、相对阈值指标之间的关系甚好,而极值指标/绝对阈值指标与相对阈值指标之间的相关关系相对较差。三峡库区夏季高温酷暑年和凉夏年的环流形势存在着明显的差异。酷暑年,乌拉尔山和鄂霍次克海地区无持续性阻塞高压,东亚大槽偏弱,西太平洋副热带高压东撤、位置偏北,同时,青藏高原上升运动减弱。这种环流形势配合有利于三峡库区夏季高温干旱的发生、发展。
中文关键词: 三峡库区, 极端高温, 环流形势, 区域性增暖
Abstract:Based on the daily temperature data during years 1961—2008, the variation regularity and relationship of the extreme high temperature indices (extreme, absolute and relative threshold indices) and its response to regional warming in the Three Gorges reservoir area were analyzed, and the changing characteristics of the high temperature days of the Three Gorges reservoir area in summer and its circulation patterns in anomalous years were studied. The results showed that the interdecadal variation of the extreme high temperature indices was the same as the average annual temperature in the recent 48 years. The variation performed a downward trend before the early 1980s, and then converted to an upward trend. The yearly change shows that in the 1980s both are low and high in other years. The relative threshold indices (HWDI,WSDI and TX90p) in the low/high years all have better consistency than the annual average temperature in the linear tendency and the correlation coefficient. The correlation analysis gave great idea on the relationship of both the extreme indices and the absolute threshold indices and the extreme indices together with the relative threshold indices. However, the relationship of the extreme indices/the absolute threshold indices and the relative threshold indices is not so optimistic. The circulation patterns have the obvious difference between in hot summer years and in cool summer years.There are not continuing block highs in Okhotsk Sea and Ural Mountains, the East Asian trough become weak, the West Pacific subtropical high retreated eastward and shifted northward, and the updraft over the Tibetan Plateau is weak. These circulation patterns are advantageous to the genesis and development of the high temperature and drought in the Three Gorges reservoir area.
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基金项目:重庆市自然科学基金计划重点项目(CSTC,2008BA0022)“三峡库区成库后极端气候事件的研究”,中国气象局业务建设项目“极端天气气候事件监测指标与业务系统建设”,重庆市气象局科技计划项目“《重庆市气候业务技术手册》相关科学技术研究”资助
引用文本:
张天宇,程炳岩,李永华,唐红玉,2010.1961—2008年三峡库区极端高温的变化及其与区域性增暖的关系[J].气象,36(12):86-93.
ZHANG Tianyu,CHENG Bingyan,LI Yonghua,TANG Hongyu,2010.Variability of Extreme High Temperature and Response to Regional Warming in the Three Gorges Reservoir During 1961—2008[J].Meteor Mon,36(12):86-93.
张天宇,程炳岩,李永华,唐红玉,2010.1961—2008年三峡库区极端高温的变化及其与区域性增暖的关系[J].气象,36(12):86-93.
ZHANG Tianyu,CHENG Bingyan,LI Yonghua,TANG Hongyu,2010.Variability of Extreme High Temperature and Response to Regional Warming in the Three Gorges Reservoir During 1961—2008[J].Meteor Mon,36(12):86-93.