Research On High Power High Frequency Radio Wave Heating Ionosphere Modeling And Numerical Simulation

Ionosphere is a natural plasma laboratory.The study on the artificially affected ionosphere not only helps people deepen their understanding of plasma characteristics,but also helps them to meet their demands for shortwave communication,over-the-horizon radar,aerospace and other fields.In this paper,based on the ionospheric heating by HF radio wave as an important way of artificial impact on ionosphere as well as the research history and significance,the physical model of radio wave heating was built up,and the related simulation was carried out.The main research results are summarized as follows:1.Based on the momentum equation,energy equation and continuity equation of magneto-fluid mechanics as well as main mechanism for ohmic heating of electric wave,the differences in main plasma parameters and physical processes of the ionospheres at different heights were considered.On this basis,in combination with ray-tracing program,the underdense heating model of lower ionosphere and the overdense heating model of higher ionosphere were respectively constructed.2.Based on the heating model of low ionosphere constructed in this paper,the background parameters of IRI-2012 and NRLMSISE-00 empirical models were used to numerically simulate the obliquely heating low ionosphere under different initial conditions,and the disturbance of electron temperature and electron density under different heating conditions was compared.The results show that the effect of radio wave heating increases with the increase of the incidence elevation angle and effective radiation power;the electron temperature and electron density decrease with the increase of wave frequency.In addition,compared with the O-wave mode,the X-wave mode causes greater extent of disturbance from electron temperature and electron density;at the same time,the X-wave mode can stabilize the electron temperature and electron density more quickly than the O-wave mode.The radio wave with smaller elevation angle,lower frequency and larger effective radiation power within a certain range enables the electron density to achieve stability more quickly;the latter two can also speed up the process of stabilizing the electronic temperature.The time required for stabilization of electronic temperature take the single-peak change with the elevation angle of incident radio wave;when the elevation angle is62°,it reaches the maximum value.In the winter and high-latitude area of northernhemisphere,the amplitude of electronic temperature disturbance caused by radio wave heating is greater;in the summer and low-latitude area of northern hemisphere,the amplitude of electronic density disturbance caused by radio wave heating is greater.3.Based on the three-dimensional heating model of high ionosphere constructed in this paper,the background parameters of IRI-2012 and NRLMSISE-00 empirical models were used to specifically simulate and analyze the heating process;after that,the heating effects under different parameter incident radio waves and ionospheric conditions with different parameter background were compared.The results show that,the change trends at meridional sections where electron temperature and electron density disturb three-dimensional structure are the same.In the non-uniform background field,the radio wave track and reflector are asymmetric,so the disturbance structures of electronic temperature and electron density are not symmetric.The electron temperatures in the heating and cooling processes will reach a stable status soon,but the development of electronic density disturbance will continue for a long time.The disturbance region range and peak height of electron temperature and electron density increase with the increase of radio frequency;they do not with the effective radiation power and wave mode of radio wave.The peak values in change rates of electron temperature and electron density increase with the increase of effective radiation power of radio wave,decrease with the increase of radio frequency and change little with the change of wave mode.In the summer and high-latitude area of northern hemisphere,the regional range and peak value of electron temperature and electron density disturbances caused by radio wave heating are greater compared to the winter and low-latitude area;in the winter and low-latitude area of northern hemisphere,the biggest disturbance of electron temperature and electron density is larger compared to the summer and high-latitude area.