کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1776472 1021679 2014 38 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Global simulation of extremely fast coronal mass ejection on 23 July 2012
ترجمه فارسی عنوان
شبیه سازی جهانی از انقباض عروق کرونال بسیار سریع در 23 ژوئیه 2012
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فیزیک زمین (ژئو فیزیک)
چکیده انگلیسی
The July 23, 2012 CME was an extremely fast backside event, reaching ∼1 AU (STEREO-A) within 20 h as compared to ∼3-6 days for typical CME events. Here, we present results from a simulation study of the CME and its driven shock using a combined kinematic and magnetohydrodynamic (MHD) simulation model, H3DMHD. In general, the model results match well with in situ measurements in the arrival time of the CME-driven shock and the total magnetic field strength, assuming an initial CME speed of 3100 km/s. Based on extrapolation of an empirical model, the fast CME and its large magnetic field (|B|∼120 nT) are capable of producing an extremely large geomagnetic storm (Dst∼−545 nT), comparable to the well-known Halloween storm in 2003, if the CME had made a direct impact to the Earth. We investigated the effect of the adiabatic index (γ). It is found that the shock tends to arrive slightly later for a smaller γ value, and γ=5/3 provides the best agreement for the shock arrival time. We also demonstrate that the strength (the Mach number) of the CME-driven fast-mode shock is not the largest at the “nose” of the CME. This is mainly due to the manifestation of fast-mode wave speed upstream of the shock.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volume 121, Part A, December 2014, Pages 32-41
نویسندگان
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