Numerical model of the sodium layer in the mesosphere: Seasonal and diurnal variation

摘要

This paper describes some computational results on the mesospheric sodium layer using the newly measured chemical reaction rate coefficients. After the most updated neutral chemistry, the calculated winter/summer ratio is consistent with the observational results. The time constant of sodium atoms is found to be shorter than 20s (70-90km). This short time constant invalidates a previous model of sodium gravity waves, which assumes that sodiums are chemically conservative during their vertical moving induced by gravity waves. We proposed a new mechanism here to explain the wavelike structures of the sodium layer drived by gravity waves.