中国近58年温度极端事件的区域特征及其与气候突变的联系

Regional characteristics of temperature changes in China during the past 58 years and its probable correlation with abrupt temperature change

运用动力学自相关因子指数Q分析中国温度的时空变化特征,得到8个不同的动力学温度变化特征区:准噶尔区、东北区、西北区、西南东区、西南西区、华北区、东南区和中南区.初步讨论了这些特征区的年均温度变化和极端温度年出现天数及其与温度突变的关系,以及不同温度段对中国近58年增暖的可能影响.研究结果表明:(1)准噶尔区、东北区等7个温度特征区近58年的年均温和极端高温的年出现天数均表现为增长趋势,极端低温天数则为降低趋势,极端高温的变化与温度增暖呈正相关,与极端低温则呈负相关.同时,北方涛动、南方涛动、北太平洋涛动和ENSO与中国北方及西南各区域温度变化相关性较显著,ElNio与中国东南区和中南区温度变化的相关性较显著;(2)对中国各区域(除东南区外)的温度增暖起主要作用的温度段为极端/相对高温段年发生天数的增加和极端/相对低温段年发生天数的减少,而常温段的作用相对较小;正是这种两头变化较大,中间变化较小的跷跷板现象导致了中国各区域的增温;(3)极端高温/低温突变发生的时间较温度突变的时间晚3—4年,即温度突变的过程可能是极端温度事件由一个相对稳定状态向另一个稳定状态演变的过程.

Based on recent studies of nonlinear science, we reconstruct dynamics of National Centre of Environment Prediction （NCEP） daily temperature series from 1948 to 2005 of grids located in China with the time-delay method and then analyse the dynamics structure by using dynamical correlation factor exponent Q. Eight significant temperature change regions are obtained. The characteristics of temperature changes and frequencies of extreme temperature in these regions are discussed, and the probable correlations between temperature changes and frequencies of extreme temperature are studied. Results indicate that, 1） the temperature and frequencies of extreme high temperature in ZhunGe＇ Er and North China both increased during the past 58 years, while frequencies of extreme low temperature in South China decreased. Furthermore, north oscillation, south oscillation, North Pacific oscillation and El Nifio-south oscillation have distinct influence on temperature changes in North China, North-East China, west of West-South China and east of West-South China, while El Nifio has distinct influence on South China and South East China. 2） The reason for warming during the past 58 years might be the increase of frequencies of extreme high temperature and the decrease of frequencies of extreme low temperature. 3） The abrupt change of extreme high/low temperature in the 1970s is 3--4 years later than that of abrupt temperature change. That is to say, the process of abrupt temperature change might be the inter-grade of extreme temperature from one stationary period to another stationary one.