高原复杂地形条件下慢天线测量值的订正  

Revision of the Measured Value of Slow Antenna under the Complex Terrain Condition of Qinghai-Tibetan Plateau

作　　者：范祥鹏[1] 张广庶[1] 王彦辉[1] 李亚珺[1] 张彤[1] 武斌[1] 

机构地区：[1]中国科学院寒旱区陆面过程与气候变化重点实验室,中国科学院寒区旱区环境与工程研究所,甘肃兰州730000

出　　处：《高原气象》2011年第4期1046-1051,共6页Plateau Meteorology

基　　金：国家自然科学基金项目(41075002,40775004,41030960)资助

摘　　要：利用青海大通地区高精度GPS时钟同步的7站慢电场变化资料,以点偶极模式为基础,运用穷举法并结合非线性最小二乘法对发生在2009年野外观测期间11个负地闪的26次回击产生的电场变化进行了拟合。对拟合结果最优的各站订正系数进行了统计,求出了以主观测站为基准的各站慢天线订正系数,即各站慢天线观测值受海拔高度和植被遮挡等因素影响程度。同时,利用各站的平均订正系数拟合得到各次回击所中和的电矩和等效电荷中心的位置。结果表明,各站慢天线都不同程度受到场地因素的影响,各种不同的环境因素对慢天线的测量有放大或屏蔽的效果,得到的订正系数是慢天线在高原复杂地形条件下各种环境因素综合作用的结果。负地闪回击中和电矩的垂直分量为11.6～66.0C.km-1,中和电矩的等效中心高度为1.6～6.8km。Using the synchronous slow electric field data at 7 stations of high precision GPS clock in Datong region of Qinghai Province in 2009, the electric field change are fitted based on the point dipole model,and nonlinear least square and exhaust algorithm methods,the field changes for 26 times of return strokes happened in 11 negative ground flashes during the field observation of 2009 were fitted,it aims to solve for the correction coefficients of slow antenna at different stations taking Mingde station as the standard,namely,how environmental factors,such as altitude and vegetation cover influence on the slow antennas at each station.At the same time,the locations of dipole moment and the moment center of the charges neutralized return strokes at each times are obtained with help of mean correction coefficients at each station.The results show that the antennas are amplified or shielded by environmental factors in varying degrees,and the correction coefficients of slow antennas are closely related to natural factors on the Plateau.The vertical component of the dipole moments neutralized by return strokes of the negative ground flashes are 11.6～66.0 C·km-1,the moment centers are 1.6 to 6.8 km.

关 键 词：慢天线 点偶极模式 非线性最小二乘法 

分 类 号：P413[天文地球—大气科学及气象学]