中国西北近45a来极端高温事件及其对区域性增暖的响应

Extreme High Temperature Events and Response to Regional Warming in Recent 45 Years in Northwest China

利用中国西北五省（区）1960-2004年100个台站逐日最高温度资料，根据百分位值法定义了不同台站逐日极端高温阈值，然后统计出了逐年逐站极端高温事件的发生频次，并进行了时空特征诊断，同时也分析了同期西北区域性增暖的响应程度。结果表明：一致性异常分布是西北年极端高温事件发生频次的最主要空间模态；西北年极端高温事件发生频次的异常空间分布可分为以下5个关键区：青海北部区、北疆区、南疆区、西北东部区及青南高原区；在西北年极端高温事件发生频次的5个空间分区中，年极端高温事件发生频次均表现．为增加趋势，除青海北部区外，其他分区年极端高温事件发生频次均未发生突变现象；在西北年极端高温事件发生频次的5个空间分区中，12～14a的周期振荡表现得比较显著；另外西北年极端高温事件发生频次同区域性增暖呈显著的正响应。

The day-to-day maximum temperature data in 1960-2004 from 100 stations in northwest China were used to determine the threshod value of daily extreme high temperature for different stations by centesimal value method, then to estimate the yearly extreme high temperature event frequency of different stations, then to diagnose their spatial-temporal distribution and analyzed their response to regional warming of northwest China. The results show that consistent anomaly distribution character is the main spatial model of annual extreme high temperature event frequency in northwest China. The spatial model in northwest China is divided into five key areas： north of Qinghai area, north of Xinjiang area, south of Xinjiang area, east of northwest China area, and south of Qinghai Plateau area. The extreme high temperature event frequency all displayed remarkable increasing tendency in the five areas during 1960-2004, showed no abrupt change except in the north of Qinghai area, and had obvious fluctuating period of 12-14 years. The extreme high temperature event frequency of northwest China positively responded to regional warming, this positive response weaken gradually from north of Xinjiang area to south of Shanxi area.