摘要
雷暴云内的电场探空是了解雷暴电荷结构的重要手段之一。为了定量了解雷暴云内的电场分布以确定雷暴的电荷结构，本文根据强电场环境中尖端放电原理，制作了尖端放电电流传感器。该电流传感器包括两根长度均为1m的同轴电缆和一个时间常数为0．1s、量程±16μA的精密电流放大电路；两根同轴电缆悬空垂直于地面，相对放大电路对称布置，两个尖端的长度为5～6cm。利用该电流传感器，同时配合温度、相对湿度、GPS等传感器，组成了雷暴云内电场综合探空仪，并于2007年夏天在甘肃平凉地区进行了初步实验。利用雷暴天气条件下的大气平均电场仪与尖端放电电流传感器进行的地面同步观测记录，得出了大气电场尖端放电电流的拟合关系，发现负电晕放电（尖端为阴极）的阈值电场和正电晕放电阈值电场存在一定差异，且负电晕放电的阈值较低。本文认为这一差异源于正、负电晕放电机制的差异。利用气球携带的电场综合探空仪进行了探空实验，得到了一次空中电场的初步探测结果，在此基础上，对探空路径上可能存在的电荷区域进行了分析。
One of the important research items in atmosphere electricity is the electric field and the electric structure of thunderstorms, which is also the foundation for investigating the initial process of lightning. For the purpose of investigating the electric structure of thunderstorms, we designed asensor for deretting corona discharges occurring in a sharply non-uniform field. The sensor is consisted of two 1 rn coaxial lines and an accurate amplifier having a time constant 0.1 s and a gain of 10 μA per volt output. The two coaxial lines are perpendicular to ground and not grounded as two symmetric electrodes, each of which has a sharp 5-6 cm long end. Based on the sensor, we made an integrated instrument for measuring ternperature, relative humidity and GPS data along the sounding path as well as the electric fields in thunderstorms. The experiment was carried out in Pingliang district, Gansu Province during the summer of 2007. The synchronized records of the average atmospheric electric field and the corona discharge current in open air on ground show that the thresholds of positive and negative corona differ only a little and the threshold of negative is lower. We think that this difference is related to the mechanism of electron avalanche of corona discharge on ground under thunderstorms. Also, a relationship between the electric field and the corona discharge current is founded by fitting the synchronized records. The data obtained from the balloonborne instrument was analyzed and a possible charge structure of along the passing way was gotten.
出处
《高原气象》
CSCD
北大核心
2008年第4期881-887,共7页
Plateau Meteorology
基金
国家自然科学基金项目(40675008)
中国科学院知识创新重要方向项目(KZCX2-YW-206)共同资助
关键词
雷暴云
电场与电晕电流拟合关系
电晕放电阈值电场
电场探空
Thunderstorm
Relationship between the corona current and the electric field
Threshold of corona discharge
Electric-field sounding
