Study On The Effect Of High Power Microwave Injection On Ozone Balance

The injection of high power microwave(HPM)into the atmosphere can affect the ozone equilibrium,which is a positive method to repair the ozone layer.The basic idea is that when HPM is propagating in the atmosphere,the ionization of atmosphere will take place,resulting in a large number of free electrons,and the formation of free electrons will affect the ozone balance including promotion of the ozone generation and Freon decomposition,etc.With the development of HPM,this method becomes feasible.Thus,it is of great practical significance to study the influence of HPM on the dynamic equilibrium of atmospheric ozone.In this paper,the differential form of Maxwell’s equations in Cartesian coordinates was derived by using the finite-difference time-domain(FDTD)method.Then,the stability of the FDTD method and both Mur and PML absorbing boundary conditions were discussed.And the numerical simulations of electromagnetic wave propagation were carried out.The results show that the maximum boundary error is less than 6×10-5 and the simulation of electromagnetic wave propagation is consistent with the actual one.On this basis,the atmospheric ionization model by HPM was established.It included Maxwell equations,electronic motion equation and continuity equation.The FDTD method was applied to the model,and the results of atmospheric ionization under different microwave conditions were calculated,including the changes of free electrons and microwave intensity in the atmosphere under different intensity,pulse width and frequency.After that,the electronic relaxation process after the withdrawal of the pulse was analyzed in detail.Combined the ionization process and the relaxation process,a whole simulation was done for the effect of HPM’s injection on free electrons.The simulation results show that under the injection of HPM in the case of 10ns,the number density of free electron can achieve 101 cm-3.Finally,the chemical reactions which were involved in the ozone balance under the injection of HPM were summarized from two aspects,one the decomposition of Freon in troposphere and one the generation of ozone in stratosphere.Combined the related chemical processes,the air ionization model and the FDTD method,the ozone equilibrium process was studied by numerical simulation.The numerical results show that under the injection of HPM,the decomposition rate of Freon in troposphere is more than 5%and the number density of ozone in stratosphere can increase by three orders of magnitude and maintain about 400 seconds.At last,a rough calculation about the loss power of Freon and ozone was given out.The results show that the use of the GW-level HPM generator to remove the Freon in troposphere and form ozone in stratosphere has a certain feasiblity,that is to say,HPM injecting into atmosphere can repair the ozone layer to some extent.