鄱阳湖生态经济区近60年极端温度事件变化特征研究

利用环鄱阳湖生态经济区6站逐日气象数据，建立了该区1952~2011年近60 a极端温度事件演化序列。研究表明：（1） 环鄱阳湖生态经济区极端高、低温事件线性趋势分别为04、-27 d/10 a；冷、热日持续指数线性趋势分别为-04、-24 d/10 a；（2）近60 a间，环鄱阳湖生态经济区内极端温度事件表现出两个明显的高频数（不稳定阶段）和低频数（稳定阶段）。其中极端高温事件和热日持续指数两个阶段分别为：1952~1979年和1980 ~2002年；极端低温事件和冷日持续指数两个阶段分别为：1952~1985年和1986~2007年；（3）近60 a以来，极端高温事件和热日持续指数在1970s晚期至1980s初期发生了较大变化，此前主要表现为叠加在弱准12~13 a周期下的强准7 a周期，之后主要表现为准9 a周期，并有不连续的4~5 a周期；极端低温日数和冷日持续指数周期性在1950s~1990s表现为弱11~12 a周期，1970s晚期至1990s则表现为弱准5 a周期；（4）环鄱阳湖生态经济区内极端低温事件是气候变暖背景下对冬季风强度的敏感响应，极端低温事件的高频数（强烈波动）主要发生在强冬季风背景下，弱冬季风条件下则出现相反情况。而极端高温事件与夏季风强度关系复杂的多，其原因尚待进一步研究

VARIATION CHARACTERISTICS OF EXTREME TEMPERATURE EVENTS IN THE POYANG LAKE ECO-ECONOMIC REGION IN THE LAST 60 YEARS

Under the global climate change,the frequency of extreme climate events increases gradually.In this context,more and more scholars pay close attention to the change of extreme temperature events.Based on daily temperature at 6 meteorological stations over the Poyang Lake eco economic region observed by the China Meteorological Administration during the 1952-2011,the extreme temperature events were analyzed.The results are as follows.(1) Over the 1952-2011 period, the linear trends of extreme temperature events in the Poyang lake eco economic region were remarkable.The linear trends of extreme high temperature events and extreme low temperature events of this region were 0.4 d/10 a, -2.7 d/10 a;the linear trends of cold and hot days sustainability index were -0.4 d/10 a,-2.4 d/10 a.(2) Over the 60 years,there were obviously two phases in terms of extreme temperature events in the Poyang lake eco economic region:high frequency and low stability phase and low frequency and high stability phase.Two phases of extreme high temperature events and hot day sustainability index were 1952-1979 and 1980-2002;two phases of extreme low temperature events and cold day sustainability index were 1952-1985 and 1986-2007.(3)Wavelets Analysis was used to analyze the periodicities of extreme temperature events in the Poyang lake eco economic region.The results of wavelet analysis indicated that the different kinds of extreme temperature events in the Poyang lake eco economic region had various periodicities in different phase from 1952 to 2011.Extreme high temperature events and hot day sustainability index had a big change from late 1970s to early 1980s.Before that time,it was shown as weak primary 12-13 a periodicity and strong primary 7 a overlying.After that,it was mainly shown primary 9 a periodicity with discontinuous 4-5 a periodicity.Extreme low temperature events and cold day sustainability index had a weak 11-12 a periodicity from 1950s to 1970s,but then changed into a weak primary 5 a periodicity from late 1970s to 1990s.(4) In this study,in order to research the relevance of extreme temperature events in the Poyang lake eco economic region and Asia monsoon change, we compared the extreme low temperature events with Asia winter monsoon and compared extreme high temperature events with Asia summer monsoon, respectively.The extreme low temperature event of this region was a sensitive response of winter monsoon under a global warming background.High frequency and strong fluctuation of extreme low temperature events were mainly seen when the winter monsoon was strong,while low frequency and weak fluctuation were mainly happened when the winter monsoon was weak.Therefore,focusing on the Asia winter monsoon change is a sort of effective way to prevent the disastrous weather which result from extreme low temperature events over the Poyang lake eco economic region.The relevance,however,between extreme high temperature events and summer monsoon is much more complex and still needs further research