Research On Categorization And Properties Of Solar Wind Plasma

Solar wind is the only star wind that human can directly detect.The whole earth is in the constantly blowing of solar wind plasma.Almost all of the Earth's events through the solar wind plasma as a medium to pass,so in-depth understanding of the solar wind plasma,its correct Classification and cognition,in-depth understanding of its various characteristics of all solar and solar plasma-related research are of great significance.In this paper,a new solar wind plasma categorization scheme,which does not depend on heavy ion data and does not require solar wind history data and shock time,is developed.Based on the new categorization scheme,the effects of different solar wind plasma and the characteristics of the four kinds of solar winds are deeply studied.The angular distribution function of solar wind magnetic field vector at 1AU is analyzed,and its dependence on solar cycle and other characteristics and applications are discussed.Firstly,this paper introduces the advantages and disadvantages of several solar wind plasma classification methods.Based on the knowledge and experience of solar wind,a list of 15 known solar winds is collected.For these lists,OMINI2 data are used to examine 9 solar wind plasma parameters,the final selection of the best solar wind list and the best combination of parameters,the development of a new plasma classification program,this program requires only three plasma parameters,namely:solar wind proton specific entropy Sp=Tp/np2/3 and the expected temperature of the solar wind associated with the solar wind speed Texp =(Vsw/258)3.113 and the actual measurement of the solar wind(Proton)temperature ratio Texp/Tp.In order to calculate these three parameters,it is necessary to measure the four most fundamental physical quantities of the solar wind:proton number density np;proton temperature Tp;magnetic field strength B and solar wind velocity Vsw.The scheme is capable of dividing the solar wind into four kinds of plasmas:Coronal Hole Origin Plasma(abbreviated as CHOP);Streamer Belt Origin Plasma(abbreviated as SBOP);Sector-Reversal-Region Plasma(abbreviated as SRRP);and plasma derived from coronal mass ejections(Ejecta).By comparing the other classification methods,using other known list cross test,show the new classification program is highly accurate,the classification results are scientific and reliable.Secondly,By using the new classification scheme,in-depth study of the solar wind plasma of the many properties at 1AU and found a new physical problem:very high speed solar wind is Ejecta;low Mach number of solar wind is mostly Ejecta,Most of the solar winds of the high Mach number are SRRP;When the magnetic field direction is perpendicular to the Parker spiral,most of the solar wind is SBOP(solar activity minimalist)or Ejecta(solar activity is great).When solar wind magnetic field long time along the radial direction,the plasma mostly are SRRP.When the solar wind magnetic field point out of the ecliptic plane,the plasma is mostly Ejecta at solar maximum,or is mostly SRRP at solar minimum.From C6+/C5+?O7+/O6+ relationship,one can find out CHOP and SBOP have similar occurrences Mechanism,Ejecta and SRRP have a similar mechanism,why is there such a similarity,worthy of further study.Finally,the angle distribution of the solar wind field at 1AU is studied in this paper.Found in a wide angle range,the fitting of the angular distribution function f(?)of the magnetic field shows that the distribution function has two main components,one at a small angle and one at a large angle.The large angle of the composition can be expressed as an exponential decay component,which may be caused by the presence of current sheets in the solar wind.The analysis of this paper shows that the solar wind magnetic field angular distribution function at 1AU,especially the second component has a solar cycle dependence,which indicates that the second component could depends on the type of solar wind;another important feature is the time scale dependence:On a wide range of time scales,with a linear relationship.This provides a constraint for the solar wind MHD turbulence model.The relevant theoretical model can refer to this observation-based time-scale characteristic to test the rationality of the model.In summary,the new plasma categorization scheme proposed in this paper is scientific and reliable,only need to measure the four fundamental solar wind plasma physical quantity,compared with other classification methods this new one is convenient,fast,and with high accuracy.With this new classification one can recognize and understand a new kind of solar wind plasma,Sector-Reversal-Region Plasma.Based on the study of the properties of solar wind plasma and the angular distribution of magnetic field at 1AU,the knowledge of solar wind plasma is deepened and the angle distribution function of solar wind field is obtained,which provides a constraint condition based on observation fact.