PROPERTIES OF THE FAST FORWARD SHOCK DRIVEN BY THE 2012 JULY 23 EXTREME CORONAL MASS EJECTION
文献类型:期刊论文
作者 | Riley, P; Caplan, RM; Giacalone, J; Lario, D; Liu, Y |
刊名 | ASTROPHYSICAL JOURNAL
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出版日期 | 2016 |
卷号 | 819期号:1页码:57 |
关键词 | shock waves solar wind Sun: coronal mass ejections (CMEs) Sun: flares |
ISSN号 | 0004-637X |
通讯作者 | Riley, P ; Caplan, RM (reprint author), Predict Sci, 9990 Mesa Rim Rd,Suite 170, San Diego, CA 92121 USA. ; Giacalone, J (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. ; Lario, D (reprint author), Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA. ; Liu, Y (reprint author), Chinese Acad Sci, Natl Space Sci Ctr, State Key Lab Space Weather, Beijing 100190, Peoples R China. |
英文摘要 | Late on 2012 July 23, the STEREO-A spacecraft encountered a fast forward shock driven by a coronal mass ejection (CME) launched from the Sun earlier that same day. The estimated travel time of the disturbance (similar to 20 hr), together with the massive magnetic field strengths measured within the ejecta (> 100 nT), made it one of the most extreme events observed during the space era. In this study, we examine the properties of the shock wave. Because of an instrument malfunction, plasma measurements during the interval surrounding the CME were limited, and our approach has been modified to capitalize on the available measurements and suitable proxies, where possible. We were able to infer the following properties. First, the shock normal was pointing predominantly in the radial direction (n = 0.97e(r) - 0.09e(t) - 0.23e(n)). Second, the angle between n and the upstream magnetic field, theta(Bn), was estimated to be approximate to 34 degrees, making the shock "quasi-parallel," and supporting the idea of an earlier "preconditioning" ICME. Third, the shock speed was estimated to be approximate to 3300 km s(-1). Fourth, the sonic Mach number, M-s, for this shock was similar to 28. We support these results with an idealized numerical simulation of the ICME. Finally, we estimated the change in ram pressure upstream of the shock to be similar to 5 times larger than the pressure from the energetic particles, suggesting that this cosmic-ray modified shock had not reached steady-state, but instead, had been caught in an early, transient phase in its evolution. |
收录类别 | SCI |
语种 | 英语 |
源URL | [http://ir.nssc.ac.cn/handle/122/5395] ![]() |
专题 | 国家空间科学中心_空间科学部 |
推荐引用方式 GB/T 7714 | Riley, P,Caplan, RM,Giacalone, J,et al. PROPERTIES OF THE FAST FORWARD SHOCK DRIVEN BY THE 2012 JULY 23 EXTREME CORONAL MASS EJECTION[J]. ASTROPHYSICAL JOURNAL,2016,819(1):57. |
APA | Riley, P,Caplan, RM,Giacalone, J,Lario, D,&Liu, Y.(2016).PROPERTIES OF THE FAST FORWARD SHOCK DRIVEN BY THE 2012 JULY 23 EXTREME CORONAL MASS EJECTION.ASTROPHYSICAL JOURNAL,819(1),57. |
MLA | Riley, P,et al."PROPERTIES OF THE FAST FORWARD SHOCK DRIVEN BY THE 2012 JULY 23 EXTREME CORONAL MASS EJECTION".ASTROPHYSICAL JOURNAL 819.1(2016):57. |
入库方式: OAI收割
来源:国家空间科学中心
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