临近空间38°N大气密度特性及建模技术

摘要

针对临近空间大气环境复杂时空变化的定量表征和仿真建模,基于11年TIMED/SABER大气密度数据,采用网格划分和数学统计的方法,得到了38°N大气密度在20～100 km的气候平均值和标准差.定量结果用于表征和分析了静态缓变气候平均态以及动态瞬变大气扰动态的变化规律,结果表明,38°N大气平均密度随高度、季节、经度变化显著.在此基础上,提出了临近空间大气密度表征为气候平均量和大气扰动量之和的建模方法,并建立了大气随机扰动自回归模型,通过仿真试验及与激光雷达大气密度实测数据的比较,结果表明该建模方法可行.%The environment of near space atmosphere is very complex.Its spatial and temporal changes are hard to be characterized and modeled.With 11 years of TIMED/SABER atmospheric density data,the climate means and standard deviations at 38°N in 20-100 km were obtained by the method of global gridding and mathematical statistics.Quantitative results were used to represent and analyze the characteristics of static slow climate changes and dynamic transient atmospheric disturbances.The results show that the atmospheric density at 38°N varies remarkably with altitude,seasons and longitude.A modeling method was set up,where the atmospheric density in near space can be represented as the sum of the climate means and atmospheric disturbances.A self-regression model was established for the atmospheric random disturbances.Model simulations were taken and compared with the lidar-observed density data,showing that the modeling method is feasible.