1961-2018年河西走廊寒潮频次时空变化特征及其环流影响因素研究

Spatial-temporal variation of cold wave frequency and its influencing factors of circulation in Hexi Corridor during 1961-2018

寒潮是我国北方地区冬、春、秋季节常见气象灾害之一,产生的危害严重影响社会经济发展和人们生产生活。河西走廊生态环境脆弱且处于寒潮影响的重要区域,揭示河西走廊寒潮频次时空变化特征可以为农牧业防灾减灾提供参考。基于1961-2018年河西走廊12个气象站逐日最低气温数据,采用数据统计和空间可视化表达方法,分析近60a河西走廊寒潮频次时空变化特征,并探讨北极涛动(AO)异常与寒潮频次的响应关系。结果表明:从时间上看,河西走廊的寒潮主要发生在10月至4月,其中11月、12月、4月为寒潮高发时期,近60a河西走廊寒潮频次呈现出下降的趋势,其中在20世纪80年代出现明显的低值,下降趋势在季节上表现为秋季>春季>冬季;河西走廊寒潮发生频次具有显著的空间差异,其中西部地区最多,东部地区居中,中部地区最少;北极涛动(AO)强弱与河西走廊寒潮频次变化具有时空响应关系,当AO处于负相位时,河西走廊各气象站寒潮发生频次较多,并且在河西走廊东部和西部表现的较为明显。

The cold wave is one of the common meteorological disasters in winter,autumn and spring in northern China,and has severely impacted on socioeconomic development and people’s lives.The Hexi Corridor is a fragile ecological environment and affected by the cold wave,revealing the characteristics of the spatial and temporal of the cold waves’frequency can provide a reference for disaster prevention and mitigation in agriculture and animal husbandry.In our study,we collected the daily minimum temperature data of12 meteorological stations in Hexi Corridor from1961 to2018,data statistics and spatial visualization methods were used to analyze the spatial-temporal variation characteristics of the cold wave frequency in the Hexi Corridor in recent60 years,and the response relation between the Arctic Oscillation(AO)anomaly and the cold wave variation was discussed.The results showed that:(1)From the perspective of time series analysis,the cold wave mainly occurred from October to April,of which November,December and April were high frequency of cold wave.The cold wave frequency showed gradual decrease from1961 to2018,and a lowest value appeared in the1980 s.From the perspective of seasonal variation,the cold wave frequency is decreasing,the trend was high in autumn,middle in spring,and low in winter.(2)The frequency of cold waves in the Hexi Corridor has obviously spatial differences.The cold wave frequency was high in the western region,while the frequency was low in the central region,and the eastern region was middle level.(3)The conditions of AO has a spatial-temporal response relation with the frequency of the cold wave in the Hexi Corridor.Cold wave was high frequency in all meteorological stations of Hexi Corridor when the AO was negative phase,especially in the eastern and western.