Effect of atmospheric space charge on initial electrification of cumulus clouds
Effect of atmospheric space charge on initial electrification of cumulus clouds
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DOI：
10.1029/jz067i010p03909
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发表时间：
1962-09
影响因子：
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通讯作者：
B. Vonnegut;C. Moore;R. G. Semonin;J. W. Bullock;D. W. Staggs;W. E. Bradley
中科院分区：
文献类型：
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作者：
B. Vonnegut;C. Moore;R. G. Semonin;J. W. Bullock;D. W. Staggs;W. E. Bradley
1960年夏天，在伊利诺伊州进行了一些实验，以确定在天气晴朗的积云之上和之下的电势梯度和空间电荷如何取决于它们生长的空气中空间电荷的极性和浓度。在对流过程中，牺牲产生的空间电荷被释放到地面附近的大气中。测量结果表明，在电改性区域形成的云比附近形成的类似云表现出明显更大的电位梯度扰动。当释放的电荷为负时，云上晴天电位梯度增大;当释放的电荷为正时，云上晴天电位梯度减小或极性相反。对云底下方的测量表明，在地面附近释放的极性空间电荷被带到云的中心，相反符号的空间电荷则在云的外部下降。实验结果表明，非降水性积云带电的极性和强度主要取决于积云所生长的空气中空间电荷的极性和浓度。根据Grenet和Vonnegut提出的对流起电过程，观测和预测之间的一致性与他们提出的电荷由上升气流和下降气流携带的观点是一致的。
During the summer of 1960, experiments were conducted in Illinois to determine how the electrical potential gradient and space charge above and beneath fair-weather cumulus clouds depend on the polarity and concentration of the space charge in the air from which they grow. Artificially produced space charge was released into the atmosphere near the ground during convection. Measurements showed that clouds that form in the electrically modified region exhibited significantly larger potential gradient perturbations than otherwise similar clouds forming nearby. When the charge released was negative, the fair-weather potential gradient over the cloud was enhanced; when it was positive, the potential gradient was decreased or of reversed polarity. Measurements just beneath the cloud base showed that space charge of the polarity released near the ground was being carried up into the center of the cloud and that space charge of the opposite sign was descending around the outer portions of the cloud. The experimental results show that the polarity and intensity of electrification of small nonprecipitating cumulus clouds is determined primarily by the polarity and concentration of the space charge in the air from which they grow. The agreement between the observations and predictions based on the convective electrification process proposed by Grenet and Vonnegut is consistent with the idea that electric charge is being carried by updrafts and by downdrafts as they have suggested.