Viscosity Coefficient of the Multicomponent Neutral Atmosphere

Abstract

The viscosity coefficient of the multicomponent neutral atmosphere calculated from the general hydrodynamic expression of a multicomponent gas mixture is compared with the approximations published and proposed in this paper for this coefficient. Two new approximate expressions for the viscosity coefficient of the multicomponent atmosphere have been found. Their relative calculation errors do not exceed 3.4 and 4.8% in the altitude range of 100 to 500 km for low, moderate, and high solar activity during daytime and nigthtime geomagnetically quiet and geomagnetically disturbed conditions at low, middle, and high latitudes. These errors are significantly smaller than the maximum relative errors (11.8–15.1%) of the viscosity coefficient calculations based on the approximations used in atmospheric studies for this coefficient. The new approximate expressions for the viscosity coefficient of the multicomponent atmosphere are recommended to be used in atmospheric studies to reduce errors in calculating atmospheric parameters.