中层顶Na层稳定性的初步研究

利用武汉大学激光雷达的观测数据验证了当前Na层数值模型的普适性．在简化模型的基础上，采用微扰法，分析模型的稳定性．计算表明，在参数的调节范围内，所有特征值的实部都小于零，这说明该模型是个稳定系统．扰动垂直波长和扩散系数对模型的所有特征值都会产生较大影响，背景温度和化学成分密度则只对某些特征值影响较大．

A PRELIMINARY STUDY ON STABILITY OF Na LAYER AT MESOPAUSE

By comparing the modeled results with observations obtained by Wuhan University Lidar, the validity of the current Na layer model is examined. With a small number of permitted adjustable parameters, the model is able to reproduce many observed features of the Na layer remarkably well. The stability of a simplified model is analyzed by using the perturbation method. It is indicated that the model is a stable system because all the model's five eigenvalues' real parts are negative when reasonably adjusting the mayor coefficients, including the wavelengths of perturbations, the concentration of the background chemical species, eddy coefficient, and temperature. The results show that the wavelengths of perturbations and the magnitude of eddy coefficient strongly influence all the five eigenvalues: the magnitudes of all the eigenvalues' real parts ascend with the increasing perturbation wavelengths and descend with the increasing eddy coefficient. However, the concentrations of the background clemical species and temperature have strong effects on only part of them.