Assuming that the meteor ablation and atmospheric sedimentation are the major source and sink of the potassium atoms, respectively, and taking the continuity equation and eddy diffusion equation for the potassium layer as dynamical controlling equations, the total concentration of all potassium species was determined in the mesopause region. According to the closed chemical reactions between different potassium species, the concentration of each potassium species was solved at each altitude. Then the model of potassium layer was established preliminarily. This paper presents the building process, input parameters and simulation results of this potassium model in detail. This model can simulate the vertical distribution of the potassium atoms. Output results of the potassium model are compared with the nocturnal annual mean potassium layer measured by lidar over Beijing. Peak density and centroid height of the potassium layer simulated by the model are in good agreement with observations, while the simulated column density and RMS width is less than the observations. The differences between simulations and observations are mainly from the bottom side of the potassium layer. Establishment and improvement of this potassium model will contribute to the study of characteristics and evolutionary process of the potassium layer.
