利用热力学与统计物理方法研究电离层E层的形成

摘要

将太阳光子作为反应物引入电离层化学反应中,运用化学热力学方法,获得低电离层光化学反应的反应度及其化学平衡常数,进而得到低电离层的电子密度,并通过统计物理方法推导出相应的化学平衡常数.结果显示,运用热力学方法得到的低电离层电子密度与Chapman理论几乎完全一致,表明利用热力学方法研究电离层的形成是可行的.分别用热力学方法和统计物理方法得到的平衡常数之间存在一定的差异,分析表明,这是因为光化学过程中并非所有光子能量都转化成了电离能,其中有一部分能量转化为热能或使粒子处于激发态,这种差异的存在使利用统计物理方法推导电离层等离子体温度成为可能.%Although it is a mature way to discuss thermo-ionization in stellar atmosphere by means of thermodynamics and statistical physics,e.g.,the mass action law,the same consideration to photoionization is difficult since many conclusions for ideal gases cannot be applied to the photon.By introducing the solar photon as a reactant into the ionosphere photochemical reaction the reaction degree and chemical equilibrium constant in the low ionosphere,and hence the electron density are obtained by means of the chemical thermodynamics method.Meanwhile,the chemical equilibrium constant can be deduced by means of statistical physics method.The results show that the electron density in the lower ionosphere derived by thermodynamics methods is nearly identical with that from the Chapman theory,proves the feasibility to study the ionosphere formation by the thermodynamics methods.However,the two equilibrium constants derived by thermodynamic and statistical physics methods independently are different.Further analysis indicates that not all photon energy is converted to ionization energy in the photochemical process,part of the energy is converted into heat or keeping the particles in the excited states.This difference hints a possibility to derive the ionospheric plasma temperature.