摘要
基于2010-2018年我国119个站点L波段探空秒级资料,通过对位温廓线法所得边界层高度进行Kmeans聚类,将我国分为青藏地区、西北地区、中部地区和东部地区4个分区,分析我国边界层高度及边界层状态(对流、中性和稳定边界层)发生频率的变化特征。结果表明:2010-2018年08:00我国年平均边界层高度均为200~600 m,以稳定边界层为主,20:00年平均边界层高度从青藏地区、西北地区、中部地区到东部地区逐渐减小,其中青藏地区和西北地区全年以对流和中性边界层状态为主,中部地区和东部地区以中性边界层为主;4个分区的月平均边界层高度在08:00逐月变化不明显,且各分区间差异不大,而4个分区20:00月平均边界层高度随时间呈单峰结构,最大值出现在春夏季,最小值出现在秋冬季,从青藏地区、西北地区、中部地区到东部地区变化幅度逐渐减小;青藏地区、西北地区和中部地区的边界层高度日变化幅度春夏季大、秋冬季小,而东部地区边界层高度日变化在不同季节特征相近。
Using K-means cluster method,the whole country is divided into four regions(Qinghai-Tibet region,northwest region,central region and eastern region)by boundary layer height(BLH)derived from potential temperature gradient method based on L-band radar sounding secondly data of 119 stations from January 2010 to December 2018.Characteristics of BLH and frequency of different boundary layer state are investigated,including convective boundary layer(CBL),neutral boundary layer(NBL)and stable boundary layer(SBL),through their interannual,annual and diurnal variations respectively.Results show that there is no significant difference in the annual average BLH and the frequencies of different boundary layer states in four regions at 0800 BT and 2000 BT from 2010 to 2018.At 0800 BT,the annual average BLH is around 200-600 m and mainly in SBL.At 2000 BT,the annual average BLH in Qinghai-Tibet region is the highest(about 1500 m),followed by northwest region and central region(about 1000 m and 500 m),and that of eastern region is the lowest(about 400 m).Qinghai-Tibet region and northwest region are mainly with CBL and NBL,while central region and eastern region are mainly with NBL.Besides,the annual variation of BLH in four regions is similar at 0800 BT,but it’s significantly different at 2000 BT.At0800 BT,the difference of one-year monthly average BLH in four regions are not obvious,and there is no clear difference among these regions.But at 2000 BT,the monthly average BLH in each region reaches maximum in spring and summer,and minimum in autumn and winter.As for corresponding annual variation of different boundary layer state frequencies,SBL’s frequency first increases then decreases while the frequencies of CBL and NBL first decrease then increase overall at 0800 BT and 2000 BT.And their turning point is in May to July.In general,the variation range of monthly average BLH and boundary layer state frequencies gradually descend from Qinghai-Tibet region,northwest region,central region to eastern region.The diurnal variations of BLH are different in four regions.In particular,the diurnal variations of Qinghai-Tibet region,northwestern region and central region show distinct seasonal difference.In Qinghai-Tibet region,the amplitude of diurnal variation can reach 2000—2300 m in spring and summer,but relatively weaker in autumn and winter.The diurnal variation in eastern region is similar in all seasons,and amplitudes are around 600 m.
作者
梁智豪
王东海
梁钊明
Liang Zhihao;Wang Donghai;Liang Zhaoming(School of Atmospheric Sciences,Sun Yat-Sen University,Zhuhai 519082;Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies,Zhuhai 519082;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081)
出处
《应用气象学报》
CSCD
北大核心
2020年第4期447-459,共13页
Journal of Applied Meteorological Science
基金
国家自然科学基金国际(地区)合作与交流项目(41861164027)
广东省科技计划(20170244,2017B020218003)
国家自然科学基金项目(41775097,41705026)。
关键词
L波段探空
边界层高度
边界层状态
时空变化
L-band sounding
boundary layer height
boundary layer state
spatio-temporal variation
