Investigation of Electric Structure of Snowfall-cloud by Simultaneous Observation of Electricity Sonde and Radar

为了研究冬季雷雨云的大气电结构，利用电探空仪和雷达进行了一些同步观测。电探空仪由测量降水粒子上的电荷和测量云中大气电势梯度两部分组成。在获得的7种情况中的6种情况中，观察到电场在云的下部或云基周围为正，而在云的上部或云顶附近为负。观察到沉淀粒子上的电荷符号与电场符号成反比关系。在最典型的情况下，雷达获得的降水回波（RHI）呈水平线形状，这意味着电荷分离不仅发生在垂直方向上，而且发生在水平方向上。因此，可以认为云中层的正空间电荷或云上层的正降水电荷直接向地面显示。这就是为什么地面正向放电主要发生在冬季雷雨云中的原因。

To investigate the atmospheric electric structure of winter thunderclouds,some simultaneous observation were carried out by means of electricity sondes and a radar. The electricity sonde is composed of a part of measuring electric charges on precipitation particles and another part of measuring atmospheric electric potential gradient in the clouds.In the six cases of the seven cases obtained, electric fields were observed to be positive in the lower part of the clouds or around cloud bases and negative in the upper part of the clouds or near cloud tops.The sign of electric charge on the precipitation particles were observed to be inverse relation with the sign of electric fields.In the most typical case, precipitation echoes obtained (RHI) by the radar had a verga shape which meaned that charge separation occured not only vertically but also horisontally. Accordingly, positive space charge in the middle level of the clouds or positive precipitation charges in the upper level of the clouds may be considered to reveal for the ground directly. This is the reason why positive ground discharge occurs predominantly in winter thunderclouds.