| From 1987 through 1993, three major campaigns, the Wave Induced Particle Precipitation, the Thunderstorm II, and the Extended Life Balloon Borne Observatories, were conducted to investigate atmospheric and global electrodynamics. Design and fabrication for balloon-borne electric field and conductivity detectors are described. The software program for a complex on-board microcontroller based data processing system has been constructed and flown on several long duration balloons, which performed data acquisition, reduction, and transmission.; Our balloon-borne measurements made near or over thunderstorms confirm early discovery of thunderstorm-related conductivity variations in the stratosphere. The signature of sferic tail was found to be of two time constants, namely a fast decay followed by a slow decay. These observations suggest that there is a strong upward coupling from thunderstorms and lightning transients to the stratosphere and possibly to the ionosphere.; Detailed and accurate knowledge of stratospheric conductivity is crucial to studying electric field and current distributions in the stratosphere, and the coupling process between the Earth and the upper atmosphere. The stratospheric conductivity measurements have been studied using ionization theory. It was found that on average the positive conductivity is about 15% higher than the negative conductivity, suggesting that the negative ion may have more water molecules than the positive ion in the stratosphere. The measured conductivity is significantly different from the values used in various global electric field models. The first global empirical model of stratospheric conductivity was developed based on a data set with long duration and wide spatial coverage.; Electric field measurements from long-duration balloon flights have confirmed the earlier discovery of a new source of stratospheric electric fields. This newly found horizontal electric field has a magnitude of 10 to 20 mV/m at night and 100 mV/m to 150 mV/m in the daytime, and has a unique characteristic of counter clockwise rotation of the field vector in the southern hemisphere, with the rotation period near to the atmospheric inertial wave period. In addition, this long-duration data set also provided the most representative measurement of the latitudinal signature of the vertical electric field and air-earth current density in the stratosphere. This latitude effect was due to atmospheric columnar resistance and the Earth's orography. |
