慢激波在快激波下游演化的限制  

THE RESTRICTION OF SLOW SHOCK EVOLUTION IN DOWNSTREAM OF FAST SHOCK

作　　者：刘绍亮[1] 

机构地区：[1]中国科学技术大学地球和空间科学系

出　　处：《地球物理学报》1995年第1期1-5,共5页Chinese Journal of Geophysics

基　　金：国家自然科学基金

摘　　要：慢激波的演化受其上游介质性质的制约，在等离子体热压与磁压之比β值和离子、电子温度比Ｔｉ／Ｔｅ大于１的介质中不利于慢波变陡形成慢激波。由飞船ＨｅｌｉｏｓＡ，Ｂ探测资料看出，在日心距０．３-１．０ＡＵ区间只有慢速太阳风流中存在有利于慢激波形成的条件。但理论计算和飞船观测指出，在快激波下游流场中β值和Ｔｉ／Ｔｅ都增大，因而在上述区间不论何种流速的太阳风中当有快激波经过后其下游流场内很难形成慢激波。The evolution of slow shock is restricted by its upstream conditions.It is disadvantage for the slow waves steepening to form a slow shock in the medium which plasma β value and ratio of proton's temperature to that of electron are larger than one.By means of the solar wind data observed by spacecrafts Helios A,B there are advantageous conditions to form slow shock only in low speed stream between the heliocentric distance 0.3-1.0 AU.But in terms of the theoretical computing results and the data observed by spacecrafts,it is indicated that the β value and the ratio Ti/Te of medium in downstream of fast Shock both are increase.On this account it iS very difficult to form Slow shock in downstream of fist shock in above region.

关 键 词：慢激波 太阳风 快激波 下游流场 

分 类 号：P353.8[天文地球—空间物理学]