近56年江西省极端高温事件的时空演变特征研究

Temporal and Spatial Characteristics of Extreme High Temperature Events in Jiangxi Province in Recent 56 years

本文根据江西省1961—2016年81个台站逐日最高气温资料,采用百分位值法、EOF分析、morlet小波等方法分析了江西年极端高温事件的时空演变特征及其对区域性增暖的响应程度。结果表明:(1)近56a江西省极端高温阈值在34℃～36.7℃之间,高值区主要出现在赣东北和赣中大部分地区,低值区位于赣北北部环鄱阳湖区和赣南南部地区;出现频次最多的地区位于赣东北和赣中吉安地区,赣南地区极端高温出现频次相对较少。(2)江西省年极端高温事件发生频次全省比较一致,此外还有北部与中南部出现相反的变化特征。(3)江西省年极端高温频次呈增长趋势,出现过2次明显的突变,同时存在12～14a、23a左右的年代际振荡周期和6～9a的年际周期。(4)江西省年极端高温事件发生频次同平均气温呈正相关,且南部地区对区域性增暖的响应较中北部明显。

The paper uses daily maximum temperature data during 1961-2016 from 81 stations in Jiangxi to determine the threshold value of daily extreme high temperature for different stations by centesimal value method, estimates the yearly extreme high temperature event frequency of different stations, diagnoses their spatial-temporal distribution and analyzes their response to regional warming. The results show that the threshold values of the extreme high temperature in Jiangxi Province vary from 34 to 36.7 degrees Centigrade, and extreme high temperature events are prone to take place in northeast and middle areas of Jiangxi compared to the southern areas. The consistent anomaly distribution character is the main spatial model of annual extreme high temperature event frequency in Jiangxi, and the spatial distribution of extreme precipitation event frequency is complex with anomaly difference between in the north and the in the mid-south of Jiangxi. The extreme high temperature event frequency all manifest increasing tendency during 1961～2016, showing two abrupt changes, and have obvious fluctuating period of 12 to14 years, 23 years and6 to 9 years. The extreme high temperature event frequency of Jiangxi positively responded to regional warming, and the response from southern regions is more significant.