Comparing parametrization of the coefficient of molecular thermal conductivity of the thermosphere

At present, different parametrizations of the molecular thermal conductivity coefficient are used in the models of the dynamics and neutral and ion composition of the thermosphere. These parametrizations have been compared by solving the energy balance equation for medium-global conditions. The spread in estimates reaches ～300 K for temperature of the thermosphere and ～40% for density at an altitude of 300 km. A new parametrization of the molecular thermal conductivity coefficient has been proposed. This parametrization is based on the renewed temperature dependences of molecular conductivity [Uribe et al., 1990] according to measurements in pure N₂ and O₂ gases and on the last theoretical estimates of O atom elastic collision sections [Kharchenko et al., 2000].