湿球温度动态阈值法在秦岭南北降雪时空规律分析的适用性研究  

Evaluation of wet bulb temperature dynamic threshold method on rainfallsnowfall separation performance in south and north of Qinling Mountains

作　　者：李双双 刘青雯 何锦屏 尚溦 LI Shuangshuang;LIU Qingwen;HE Jinping;SHANG Wei(School of Geography and Tourism,Shaanxi Normal University,Xi’an 710119,China)

机构地区：[1]陕西师范大学地理科学与旅游学院,陕西西安710119

出　　处：《冰川冻土》2023年第5期1490-1500,共11页Journal of Glaciology and Geocryology

基　　金：国家自然科学基金项目(41771030,41877519,41701592);陕西省自然科学基础研究计划青年项目(2021JQ-311);陕西师范大学研究生创新团队项目课题(TD2020035Y)资助。

摘　　要：基于秦岭南北72个气象站点逐日观测数据,对湿球温度动态阈值法在中国南北过渡带降雪研究的适用性进行分析。结果表明:受冬季风、山地地形和下垫面性质等因素影响,秦岭南北降雪判断准确率的时空规律存在两阶段特征。第1阶段为:11月—次年1月,区域降雪判断准确率空间呈现“南北分异”分布,关中平原和秦岭山地,是降雪判断准确率的高值区;第2阶段为:次年2—3月,降雪判断准确率空间呈现“东西分异”分布,汉江流域上游、秦岭山地西段、关中平原东部为降雪判断准确率的高值区。[-2.0℃,2.0℃]气温区间,是秦岭南北降雪类型判断准确的关键温度区间。当区域强烈降温至0℃以下,湿球温度动态阈值法,可准确地识别11月—次年1月关中平原、秦岭山地和汉江流域上游的降雪相态。本研究结论启示,客观降雪相态方法验证研究可借鉴地理时空思维,关注不同时间、不同温度、不同地理单元的组合关系,重视雨雪相态判断准确率的时空差异规律。Snowfall is a critical component of hydrological process in the mountainous regions,which can re⁃flect climate change effectively due to its high sensitivity to alternations in temperature and precipitation.Gain⁃ing a better understanding of rain-sleet-snow performance is therefore essential for hydrological process studies.Based on daily meteorological data from 72 stations in the south and north of Qinling Mountains,the research is an analysis of applying wet bulb temperature dynamic threshold method in China’s north-south transition zone from three perspectives,differing in month,temperature range and geographical sub-region.The results showed that:(1)Under the influences of winter wind,water vapor transport,mountain terrain and underlying surface properties,most snowfall in the north and south of Qinling Mountains fall in December to February of the follow⁃ing year.Typically,the spatial variations of snowfall days increase from late autumn and early winter to late winter and early spring,compounded by reaching the peak value in February.(2)There are‘two-stage’charac⁃teristics in the accuracy of snow judgment in the north and south of Qinling Mountains.The first stage is from November to January of the following year.At this stage,the accuracy of snowfall judgment is above 0.75 in most areas.The second stage is February to March of the following year.Accuracy of regional snowfall judg⁃ment has decreased among this stage.(3)Spatially,at the first stage,the spatial distribution shows‘North-South differentiation’.The high value areas for judging the accuracy of regional snowfall are Guanzhong Plain and Qinling Mountains.While at the second stage,the spatial distribution shows the characteristics of‘East-West differentiation’.The high value areas for judging the accuracy of regional snowfall are upper reaches of Hanjiang River Basin,western Qinling Mountains and eastern Guanzhong Plain.(4)The key temperature range for accurate judgment of snowfall in the north and south of Qinling Mountains

关 键 词：气候变化 降水类型 湿球温度动态阈值法 降雪 秦岭南北 

分 类 号：P468.025[天文地球—大气科学及气象学]