1961~2020年浙江省极端气候事件的时空演变特征

Extreme Climate Events in Zhejiang Province from 1961 to 2020 Space-Time Evolution Characteristics

摘要: 近年来，频繁的极端气候事件严重影响了浙江省社会发展和人类生产生活。作为亚热带典型山地区域，浙江省极端气候事件对环境和生态系统的影响更加显著。本文利用了浙江省内23个气象站点近60年的气温和降水数据，运用RClimDex模型计算了极端气候事件指数。使用线性趋势分析和Mann-Kendall检验等方法研究浙江省极端气候指数的时空变化特征并采用交叉小波变换方法研究了导致浙江省极端降水事件发生的影响因素。结果显示：(1)过去60年，浙江省气候总体呈现变暖和湿润趋势，极端高温事件和发生频率增加，极端低温事件则减少，气温上升显著。(2)极端气温持续指数与极端气温指数一致，暖事件数量和持续性增加。(3)极端降水事件指数增加，持续湿润指数减少，表明降水总量和强度显著增加，但集中在特定时间段。(4)极端温度事件在90年代发生突变，21世纪后变化更为迅速；极端降水事件主要在80年代产生突变。(5)在空间尺度上，南部极端暖指数较高，北部较低，降水指数表现为南部高于北部。交叉小波变换的结果表明太阳黑子与极端降水指数的共振周期时间最长，说明太阳黑子对极端降水事件影响最大。

Abstract: Over the past few years, recurrent severe weather patterns have significantly impacted the societal progress and the daily lives of people in Zhejiang Province. As a typical mountainous area in the subtropics, extreme climate events in Zhejiang Province have more significant impacts on the environment and ecosystems. This paper uses the temperature and precipitation data of 23 meteorological stations in Zhejiang Province in the past 60 years, and uses the RClimDex model to calculate the extreme climate event index. By employing linear trend analysis and the Mann-Kendall test, the temporal variation characteristics and significance of extreme weather index in Zhejiang Province were studied. Ultimately, the spatiotemporal evolution traits and influencing elements of extreme temperature and precipitation occurrences in Zhejiang Province were scrutinized through cross-wavelet transformation and supplementary methodologies. The results show: (1) In the past 60 years, the climate in Zhejiang Province has generally shown a warming and humid trend, with an increase in the frequency of extreme high temperature events, a decline in extremely cold weather occurrences and a notable rise in temperatures. (2) The extreme temperature persistence index is consistent with the extreme temperature index, and the number and persistence of warm events increase. (3) The extreme precipitation event index increases and the sustained wetness index decreases, indicating that the total amount and intensity of precipitation increase significantly, but are concentrated in a specific time period. (4) Extreme temperature events mutated in the 1990s, and changed more rapidly after the 21st century; extreme precipitation events mutated earlier, mainly in the 1980s. (5) On a spatial scale, the extreme warm index is higher in the south and lower in the north, and the precipitation index is higher in the south than in the north. Cross wavelet transform shows that the East Asian summer monsoon, El Niño-Southern Oscillation and sunspots have a certain resonance period with the extreme precipitation index, among which sunspots have the greatest impact on extreme precipitation events.