雷暴下地面自然尖端电晕放电离子时空演化的数值模拟

为了对雷暴云下近地面的电特性进行分析，本文建立了模拟自然尖端所产生的电晕离子演化的一维数值模式。以地面电场为基础，考虑到地面电晕离子的演化，成功地计算了从地面至８００ｍ的空中电场及电荷、电流的时空演变，发现地面电晕离子可解释除雷暴云电荷影响外的空中电场和地面电场的差异，空间电场比地面电场更能反应雷暴电荷所产生的电场。空间电荷层可延伸到８００ｍ的高度上，且电荷密度可高达０．２５ｎＣ／ｍ^３，６００ｍ高度上的传导电流密度可达０．１ｎＡ／ｍ^２。

NUMERICAL CALCULATION OF EVOLUTION OF CORONAIONS PRODUCED FORM THE GROUND UNDER THUNDERSTORM

A one-dimensional model for estimating the production and evolution of corona ions from natural point discharge under thunderstorm was developed for the study on the characteristics near the ground under thunderstorm. Basing on the electric field measured at the ground, the temporal and spatial distribution of electric field, charge density and conduction current density were numerically calculated within 800m above the ground under thunderstorm. The results show that the corona ions at the ground can explain the difference of electric field at the ground and that in altitudes. Electric field at the altitude can reflect the electric intensity of cloud charge more reasonably than that measured at the ground. Space charge layer can extend up to 800m above the ground and the charge density at this altitude is 0.2nC/m³,the conduction current density at 600m is 0.1nA/m².