摘要
针对中国内陆高原地区雷暴多为孤立且尺度较小的特征,假定孤立雷暴在闪电发生前,当地面电场处于平稳状态时,云内的电荷区在水平方向上均匀分布,且只与垂直高度有关。根据云厚可将雷暴云在垂直方向上分为若干个厚度相等的区域,地面电场值即为雷暴云内多个水平均匀分布的电荷区域共同作用的结果。在此理论假设基础上,利用甘肃中川地区一次典型雷暴过程引起的多站地面电场观测资料,对该雷暴过程的电荷结构及其演变特征进行最小二乘法的拟合研究。结果表明,在雷暴发展演变过程中,其下部始终存在一范围和强度都较大的正电荷区,同时在雷暴云顶部存在强度较小的负电荷区,使得雷暴整体上呈四极性电荷结构。通过与雷达回波的对比,发现雷暴电荷中心与雷达强回波中心位置大体一致。
According to the characteristic of thunderstorm in Chinese inland plateau,i.e.,the most of them are isolated and have a small scale,those were assumed that the charge region of thunderstorm is well-proportioned in horizontal and only depend on vertical height in any random time.Then,the thunderstorm can be divided into several regions with the same depth.The surface electric field of thunderstorm can be comprehended by the collective contributions of the several well-proportioned charge regions with uniform depth.Based on the supposition,the charge structure in a typical thunderstorm of Zhongchuan area is analyzed by the observation of multi-station E field.The results show that a larger-than-usual lower positive charge center exists at the base of thunderstorm and a weaker negative charge layer exists at the top.Totally,the thunderstorm have four charge regions.Contrast the observation of radar,the charge center position is basically consistent with the strong radar echo,which indicates that,in a way,the supposition is applicable for the charge structure analysis of isolated thunderstorm with small scale.
出处
《高原气象》
CSCD
北大核心
2010年第6期1524-1532,共9页
Plateau Meteorology
基金
国家自然科学基金项目(40905001
40775004)资助
关键词
内陆高原
雷暴
地面电场
电荷结构
Inland plateau
Thunderstorm
Surface electric field
Charge structure
