中国西北近45a来极端低温事件及其对区域增暖的响应  

Extreme Low Temperature Events in Northwest China and Their Response to Regional Warming in the Recent 45 Years

作　　者：杨金虎[1] 沈永平[2] 王鹏祥[1] 杨启国[1] 

机构地区：[1]中国气象局兰州干旱气象研究所甘肃省干旱气候变化与减灾重点实验室中国气象局干旱气候变化与减灾重点开放实验室 [2]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000

出　　处：《冰川冻土》2007年第4期536-542,共7页Journal of Glaciology and Geocryology

基　　金：科技部科研院所社会公益研究专项(2005DIB3J100;2004DIB5J192);甘肃省科学技术攻关计划项目(ZGS042-A44-017);干旱气象科学研究基金项目(IAM200609)资助

摘　　要：利用中国西北五省(区)1960-2004年100个台站逐日最低温度资料,通过百分位法定义了不同台站的逐日极端低温阈值,对近45 a来西北地区逐年极端低温事件发生频次进行了时空诊断,并分析其同西北区域性增暖的响应.结果表明:一致性异常分布是中国西北年极端低温事件发生频次的最主要空间模态;中国西北年极端低温事件发生频次的空间分布可分为以下5个关键区:北疆区、青海北部区、西北东部区、南疆区及青南高原区;年极端低温事件发生频次除了青南高原区表现为微弱的减少趋势外,北疆区、青海北部区、西北东部区和南疆区均表现为显著的减少趋势,并且发生了突变现象.在年极端低温事件发生频次的各主要空间分区中,13～15 a和7～8 a的周期在所有分区中反映得比较清楚;年极端低温事件发生频次对西北区域性增暖呈显著负响应.Using the daily minimum temperature data of 100 stations in Northwest China in 1960-2004, the thresholds of daily extreme low temperature are determined for different stations, diagnosis of the frequencies of temporal and spatial distributions of annual extreme low temperature events is made for the recent 45 a, and their response to regional warming in Northwest China is analyzed. The result shows that consistent anomaly distribution is the principal spatial mode of the frequencies of annual extreme low temperature events in Northwest China ; it is found that the spatial mode can be divided into five key areas： north of Xinjiang Region, north of Qinghai Province, east of Northwest China, south of Xinjiang Region, and the plateau in south of Qinghai Province; It is proved that the frequencies of extreme low temperature events show a remarkable decreasing tendency in the north of Xinjiang Region, north of Qinghai Province, east of Northwest China and south of Xinjiang Region, with some abrupt changes. However, there is a weak decreasing tendency in the plateau in south of Qinghai Province. It is also found that the vibration periods of 13～15 a and 7-8 a are displayed very clear in all the five key areas. It is also proved that the frequencies of extreme low temperature events in Northwest China show a remarkable negative response to regional warming.

关 键 词：中国西北 极端低温 时空演变 增暖响应 

分 类 号：P467[天文地球—大气科学及气象学]