北京山区和平原地区夏季雨滴谱特征分析  

Microphypical Characteristics of the Raindrop Size Distribution Between Mountain and Plain Areas over Beijing in Summer

作　　者：赵城城 张乐坚[2] 梁海河[2] 李林 柳云雷 ZHAO Chengcheng;ZHANG Lejian;LIANG Haihe;LI Lin;LIU Yunlei(Weifang Meteorological Office of Shandong Province,Weifang 261011;CMA Meteorological Observation Centre,Beijing 100081;Beijing Municipal Meteorological Observation Centre,Beijing 100089;Dalian Meteorological Bureau of Liaoning Province,Dalian 116001)

机构地区：[1]山东省潍坊市气象局,潍坊261011 [2]中国气象局气象探测中心,北京100081 [3]北京市气象探测中心,北京100089 [4]辽宁省大连市气象局,大连116001

出　　处：《气象》2021年第7期830-842,共13页Meteorological Monthly

基　　金：国家重点研发计划(2018YFC1507502);山东省气象局青年科研基金项目(2018SDQN14)共同资助。

摘　　要：山区和平原地区降水的雨滴谱特征由于下垫面等因素的影响有时存在较大的差别,分析两者的差异有助于深入理解降雨的微物理特征以及对提高不同下垫面雷达定量估测降水的准确性起到重要作用。利用2017—2018年北京地区夏季雨滴谱站和自动站资料,选取延庆站和大兴站分别代表北京山区和平原地区,通过降水分类方法研究了两站不同降水类型雨滴谱分布的特征。研究结果表明,北京地区夏季雨强(R)≤5 mm·h^(-1)的降水频次较多(山区和平原站均为86.0%),但对整体雨量贡献较小(山区站为33.0%,平原站为29.0%);而R>5 mm·h^(-1)的降水频次较少,却对整体雨量贡献较大。较为深入的研究表明,对流云降水比层状云降水具有更大的质量平均直径(D_(m))、标准化参数lgN_(w)和分布谱宽。两站相比,延庆站(山区站)不同降水类型的D_(m)(lgN_(w))均大于(小于)大兴站(平原站),表明北京山区滴谱粒径偏大、数浓度偏低。与国外经典对流滴谱相比,山区(平原)更倾向于大陆性(海洋性)对流滴谱。对D_(m)-R关系、lgN_(w)-R关系、μ(谱型)-Λ(斜率)关系和Z-R关系的分析表明,这些关系都符合经典研究结论,但是拟合的参数与其他地区具有一定的差别,体现出北京地区不同下垫面与其他研究结果的差别。延庆站和大兴站的Z-R拟合关系分别为Z=764R^(1.20)和Z=386R^(1.32),其中大兴站的Z-R关系与代表夏季对流云降水的Z=300R^(1.40)较为一致,而延庆站的则与其存在一定差别,体现出北京山区和平原降水的差异。Due to the influence of surface and other factors,the raindrop size distribution characteristics of rainfall in mountainous and plain areas have significant differences in some cases.Understanding their differences in mountain and plain is useful to deeply learn the microphysical characteristics of rainfall and improve the accuracy of radar quantitative precipitation estimation(QPE)with different underlying surfaces.Based on the raindrop spectrum data from laser optical disdrometer and the rainfall data from automatic weather stations over Beijing during summers of 2017 and 2018,the representative mountain-area Yanqing Station and plain-area Daxing Station were selected.The raindrop size distribution characteristics of convective and stratiform rain types at the two stations were studied by the rain type classification method.The results show that the contribution of rainfall intensity(R)greater than 5 mm·h^(-1)with lower frequency to the total rainfall is dramatically larger than that(mountain/plain station is 33%/29%)less than or eaqual to 5 mm·h^(-1)with higher frequency(both stations are 86%)in the Beijing summer.Further research indicates that convective rain spectra has larger mass-weighted mean diameter D_(m),logarithmic generalized intercept parameter lgN_(w) and distribution spectrum width than the stratiform rain spectra.Comparing the two stations,we find the D_(m)(lgN_(w))of different rain types at Yanqing Station(mountain station)is larger than(less than)that at Daxing Station(plain station),indicating that the mountain area raindrop size is larger while number concentration is lower.Compared to foreign classical convective spectra,the convective rain spectrum at mountain(plain)area is more inclined to the continental(maritime)convection.Relationships among D_(m)-R,lgN_(w)-R,μ(shape)-Λ(slope)and Z-R are in accordance with the classical findings,but the fitted parameters are different from those of other areas,which means the variations by different researches.The Z-R fitted relationships bet

关 键 词：雨滴谱分布 GAMMA分布 D_(m)-lgN_(w)分布特征 Z-R关系 

分 类 号：P412[天文地球—大气科学及气象学]