ELECTRIC CONDUCTIVITY IN THE LOW THERMOSPHERE AND LOW AND MIDDLE ATMOSPHERE AND ITS AFFECTION BY SOLAR ACTIVITY

A global model of the atmospheric conductivity in the region below 200 km is calculatedusing the latest measured data and chemical model of the middle atmosphere. The influencesof various sources of ionization, i.e., cosmic rays, solar EUV radiation and X-ray radiation,are analzed. The numerical results show that the relative sensitivity of conductivity to thewhole ionization sources is about 50% for the most part of altitude. Using the semi-empiri-cal formulas for the cosmic-ray ion-pair production rate, up to more than 50% relative modu-lation of the atmospheric conductivity by the 11 year solar cycle is obtained near the polarregion and below 70 km. The calculated global resistance of the whole atmosphere is 182Ω.The comparison of the calculation with observation and other semi-empirical model shows afairly good agreement.