The charge structure in a thunderstorm based on three-dimensional electric field sonde

A double-metal-sphere three-dimensional electric field sonde was developed successfully, and the thunderstorm electric-meteorological integrated sounding system was constructed in combination with weather radiosonde to measure the comprehensive sounding data of electric field, temperature and relative humidity. In summer of 2019, the field experiment was carried out in the North China Plain. The vertical electric filed profile and the corresponding charge structure inside the thunderstorm in this region are presented for the first time, through analyzing the sounding data, and synchronous surface electric field, radar echo and the three-dimensional wind field given by Variational Doppler Radar Analysis System (VDRAS). The sounding system was released during the dissipation stage of a mesoscale convective system (MCS) on August 7, 2019 and passed through the weak echo region of the thunderstorm. The sounding results show that there were five charge regions in the thunderstorm and the charge polarity altered in the vertical direction. The upper positive charge region was at 4. 4 similar to 5. 6 km (near 0 degrees C), and the complex middle negative charge region was at 3. 6 similar to 4. 4 km. The height of lower positive charge region was 1. 0 similar to 3. 6 km. Besides, there was a negative charge region below 1 km, and a weak negative shielding charge region was near the top of the thunderstorm. Both middle negative charge region and lower positive charge region were composed of several charge layers with different thicknesses and charge densities. Furthermore, the electric field sounding system experienced the stages of rising, falling and rising again during 3. 6 similar to 4. 4 km, which were in the range of the middle negative region. The sounding data indicates that the dynamic field inside the cloud was complicated, and the detailed charge structures of the three stages in the negative charge region were similar but different, which reflected the real charge structure inside the thunderstorm was very complicated and inhomogeneous spatio-temporally.