Studying Changes In Neutral Atmospheric Density And Temperature Using Flow Echo Height

The meteors on the earth are mostly located in the middle top of the ground 80 to 100 km away.The meteors are generated by the meteorites and dust in the universe.The friction with the atmosphere is generated,and the combustion of the meteorite and the dusty jade atmosphere forms a plasma column,which is the meteor we see in our eyes.Large radar signals on the ground can collect motion information from the plasma column and then process the data.We can use this information to do a lot of scientific research.Detecting changes in the upper atmosphere is an important and challenging issue.Changes observed by meteor radar at the height of the meteor peak should contain neutral density information in the meteor ablation zone.In this work,I collected nearly 20 years.The meteor radar observation data of Wuhan to complete this work,collected the time distribution of the peak height of the flow,and determined the height of the meteor peak by the least squares fitting of the height distribution of the meteor radar echo using the normal distribution hypothesis.To study the peak height and seasonal variation of meteors,and to study local atmospheric density changes and wind direction changes using meteor echo heights.The ionosphere is a neutral atmosphere of the Earth's ionization.It is part of the upper atmosphere.There are a large number of free electrons in this area.The movement of free electrons can affect the propagation of radio waves.The ionosphere is part of the upper atmosphere.In recent years,through continuous research and exploration of the upper atmosphere,people have increasingly found that the upper atmosphere ionosphere plays a very important role in meteorological problems.The meteor radar introduced in this paper is one of the important tools to study and explore the atmospheric parameters of the region.Meteor radar plays a very important role in the detection of atmospheric wind field,tidal wave,planetary wave and density temperature of the upper atmosphere.Therefore,we can use the motion law of the meteor trail collected by meteor radar to study many atmospheric parameters of the middle and upper atmosphere.The purpose of this paper is to use the meteor radar to study the variation of density and temperature near the top of the middle layer.This is only part of the action of meteor radar.The meteoroid is mainly burned and gasified near the middle of the upper atmosphere,and diffuses in the atmosphere in the form of bipolar diffusion,forming a meteor trail,using the meteor trail motion law and the height and diffusion time detected by the meteor radar.The bipolar diffusion coefficient of the atmosphere in this region can be fitted.The bipolar diffusion coefficient has a certain correlation with the temperature and density of the atmosphere,and then the parameters such as density and temperature of the upper atmosphere are reversed.Through research,the meteor trail is mainly diffused in the form of bipolar diffusion.Using the motion law of the meteor trail detected by the meteor radar,we can study the bipolar diffusion coefficient of the atmosphere in the region.The meteor radar can accurately calculate the occurrence of the meteor trail.The bipolar diffusion coefficient(Da)of the region,using the data of the bipolar diffusion coefficient obtained from the meteor wake,can further obtain the empirical relationship between the bipolar diffusion coefficient and the height: the relationship between h and Da,calculated in all months,bipolar The elevation of the diffusion coefficient is approximately 6-8 km,which is 1-1.5 km larger than the atmospheric pressure elevation given by the CIRA--86 mode.In Chapters 4 and 5,we have derived the derivation and calculation of theoretical knowledge,and analyzed the methods of using the data provided by meteor radar to calculate the parameters of temperature,pressure,density and elevation near the top of the middle layer,and drawn the middle layer of Wuhan.The annual temperature change and the short-term change map of temperature density are analyzed,and the annual and short-term fluctuations of the neutral atmospheric parameters near the top of the middle layer are analyzed and inferred.In summary,the work of this paper is of great significance for understanding the changes of atmospheric pressure density,atmospheric temperature changes,and the influence of wind field in the MLT region on the low ionosphere.