Solitary wave characteristics on the fine structure of mesospheric sporadic sodium layer

Abstract. The most fantastic phenomenon of the mesospheric sodium layer is the so-called sporadic sodium layer (SSL or NaS), which are proposed to be closely related to wave fluctuations. Solitary wave is a particular solution of partial differential equation whose energy travels as a localized wave packet, and a soliton is a special solitary wave which has a particle-like behavior with strong stable form. In this research, the solitary wave theory is applied for the first time to study the fine structure of NaS. We perform soliton fitting processes on the observed data from the Andes Lidar Observatory, and find out that 24/27 NaS events exhibit similar features/characteristics to a soliton. Time series of the net anomaly of the NaS reveal the same variation process to the solution of a generalized five-order KdV equation. Our results therefore suggest the NaS phenomenon would be an appropriate tracer for nonlinear wave studies in the atmosphere.