摘要
基于1970—2020年逐日最高温和最低温数据,对秦岭南北夏季昼夜复合高温时空变化特征进行分析,探讨不同分区昼夜复合高温变化与海温、大气环流异常的相关关系。结果表明:①1970—2020年,秦岭南北夏季昼夜复合高温显著增加。其中,关中平原昼夜复合高温增速最快(0.93 d/10a),是秦岭南坡(0.54 d/10a)的1.7倍。②空间上,昼夜复合高温天数格局呈现“谷地高、山地低”的分布特征,高值区主要分布于:关中平原、汉中盆地、安康盆地和丹江口水库周边。有35.0%的区域昼夜复合高温呈显著增加趋势,空间分布于:关中平原西段黄土台塬区、嘉陵江流域、秦岭山地西段和大巴山区。③在影响因素上,春季青藏高原500hPa气压变化与3个子区夏季昼夜复合高温异常呈显著正相关。即春季青藏高原500hPa气压异常偏强时,秦岭南北夏季昼夜复合高温天气发生风险较高。
In a warming climate,compared to individual hot days or nights,summertime compound hot extremes(SCHEs)that daytime and nighttime heat sustained are more dangerous for urban residents.Based on the daily maximum and minimum temperature data,the study investigated the spatiotemporal variation of SCHEs over the north and south of the Qinling Mountains during 1970-2020.Meanwhile,we analyzed the relationship between SCHEs and sea surface temperature anomalies(SSTAs),atmosphere anomalies to understand the possible mechanisms for the decadal variation.The results show that:(1)The SCHEs increased significantly in the north and south of the Qinling Mountains.Stage of 2013-2020 was the burst period of the SCHEs,the number of days which occurred SCHEs reached an unprecedented record in the past 51 years.(2)Spatially,the pattern of the SCHEs was characterized by"higher in valley and lower in mountain".The regions with most frequently occurring events were Guanzhong Plain,Hanzhong Basin,Ankang Basin and areas around the Danjiangkou Reservoir.Notably,the SCHEs increased significantly accounted for 35.0%of the regions,which were mainly distributed in the loess tableland of western Guanzhong Plain,Jialing River Basin,western Qinling Mountains and Daba Mountains areas.(3)For the period of 1991-2020,regions observing stronger increases in the occurrence area see larger increases in compound hot extremes days(relative to 1971-2020).The stage between mid-July and the end of August is the key period of the increases in frequency and intensity of SCHEs.(4)In terms of teleconnection patterns,the SSTAs of Niño W region(0°-10°N,140°E-180°E)in the preceding winter or spring showed a significant positive correlation with the SCHEs in the Guanzhong Plain(p<0.05).And the spring atmospheric pressure at 500 hPa of the QinghaiTibet Plateau showed a significant positive correlation with the SCHEs in three sub-regions,which could be regarded as an early warning signal for hot extremes.When the spring 500 hPa pressure over the Qinghai-Tibet Plateau is abnormally higher,the SCHEs will be abnormally more frequent in the north and south of the Qinling Mountains.The conclusions can provide a theoretical basis for understanding the law of climate change in the north-south transitional zone of China and formulating adaptation measures such as spatial management,hydropower resource allocation and hot extremes warning.
作者
李双双
胡佳岚
何锦屏
任涛涛
延军平
LI Shuangshuang;HU Jialan;HE Jinping;REN Taotao;YAN Junping(School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,China)
出处
《地理研究》
CSSCI
CSCD
北大核心
2023年第5期1410-1424,共15页
Geographical Research
基金
国家自然科学基金项目(42171095、41877519、41771030、41701592)。
关键词
气候变化
昼夜复合高温
厄尔尼诺
时空分析
秦岭南北
climate change
compound hot extremes
El Niño
spatiotemporal analysis
north and south of Qinling Mountains
