Statistical Study on the Geomagnetic Substorm
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摘要: 利用AL和AE指数对第24个太阳活动周发生的亚暴事件进行统计分析.主要统计了关于磁层亚暴的强度,亚暴初值与恢复值的关系,亚暴持续时间,亚暴恢复相与增长相(包括膨胀相)持续时间的关系等.统计结果表明:在第24个太阳活动周中2008-2016年发生的亚暴事件大部分比较剧烈,其峰值大都在200~1200nT;初值和恢复值大都在30~100nT,并且事件占比符合正态分布;大部分亚暴都能恢复到亚暴初值60nT以内,并且差值越小,事件的占比越大.大部分亚暴的持续时间较长,在100~400min之间,其中增长相(包括膨胀相)持续时间均在120min以内,并且持续时间越长,其事件占比越小;大部分亚暴事件的恢复相持续时间在60~300min之间,并且呈现出正态分布特征.绝大多数亚暴事件的恢复相持续时间为增长相持续时间的10倍以下,其中约一半亚暴事件的恢复相持续时间为增长相持续时间的1~4倍.这说明亚暴的能量聚集速度约为能量释放速度的1~4倍.Abstract: The substorm is a process that releases enormous energy in the magnetosphere, including auroral, ionospheric, magnetospheric and thermospheric substorms. The substorm can result in severe disturbances in the whole magnetosphere and ionosphere. In this work, the AL and AE indices are employed to analyze the substorm events in the 24th solar cycle. Statistical analysis is performed on the relationship between the intensity of substorm, the initial value of substorm and the recovery value, the duration of a substorm, the relationship between substorm recovery phase and the duration of the growth phase (including expansion phase) and so on. The statistical results show that: most of the substorm events occurred in the 24th solar activity cycle from 2008 to 2016 are severe, with the peak value of the substorm mostly around 200~1200nT; the duration of most of the substorms ranges from 100 to 400min, the duration of the recovery phase of most of the substorms is between 60 to 300min, and presents the normal distribution characteristics; the recovery phase duration of most substorm events is less than 10 times of the growth phase duration. The statistical results on the substorm are helpful for further understanding of the occurrence and development of substorm in the magnetosphere. Therefore, it is of practical significance to further understand the energy evolution process in the magnetosphere.
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Key words:
- Substorm intensity /
- Substorm onset /
- Substorm duration /
- Solar activity circle
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[1] LASSEN K, SHARBER J R, WINNINGHAM J D. The development of auroral and geomagnetic substorm activity after a southward turning of the interplanetary magnetic field following several hours of magnetic calm[J]. J. Geophys. Res., 1977, 82(32):5031-5050 [2] MCPHERRON R L. Magnetospheric substorms[J]. Rev. Geophys. Space Phys., 1979, 17:657-681 [3] BAKER D N, PULKKINEN T I, ANGELOPOULOS V, et al. Neutral line model of substorms: past results and present view[J]. J. Geophys. Res., 1996, 101(A6):12975 [4] BAUMJOHANN W, KAMIDE Y, NAKAMURA R. Substorms, storms, and the near-earth tail[J]. J. Geomag. Geoelectric., 1996, 48(2):177-185 [5] MENG C I, KAN LIOU. Substorm timings and timescales: a new aspect[J]. Space Sci. Rev., 2004, 113:41 [6] BLAGOVESHCHENSKⅡ D V, ROGOV D D, ULICH T. Variations in the horizontal correlation radius of the ionosphere during a magnetospheric substorm[J]. Geomag. Aeronomy, 2013, 53(2):166-176 [7] BAKER D N, JAYNES A N, TURNER D L, et al. A telescopic and microscopic examination of acceleration in the June 2015 geomagnetic storm: magnetospheric multiscale and vanallen probes study of substorm particle injection[J]. Geophys. Res. Lett., 2016, 43(12):6051-6059 [8] PU Zuyin, FU Suiyan, LI Yaoting, et al. A near earth triggering model for the magnetospheric substorm expansion phase[J]. Chin. J. Space Sci., 1994, 01:30-38 [9] LUI A T Y. Current disruption in the Earth's magnetosphere: observations and models[J]. J. Geophys. Res. Space Phys., 1996, 101(A6):12975-13010 [10] EASTWOOD J P, NAKAMURA R, TURC L, et al. The scientific foundations of forecasting magnetospheric space weather[J]. Space Sci. Rev., 2017, 212(3-4):1221-1252 [11] LI H, WANG C, PENG Z. Solar wind impacts on growth phase duration and substorm intensity: a statistical approach[J]. J. Geophys. Res. Space Physics, 2013, 118:4270-4278 [12] CHU X, MCPHERRON P L, HSU T S, et al. Solar cycle dependence of substorm occurrence and duration: implications for onset[J]. J. Geophys. Res. Space Phys., 2015, 120:2808-2818 [13] LIOU K, SOTIRELIS T, RICHARDSON I. Substorm occurrence and intensity associated with three types of solar wind structure[J]. J. Geophys. Res.: Space Phys., 2018, 123:485-496 [14] NEWELL P T, GJERLOEV J W. Evaluation of SuperMAG auroral electrojet indices as indicators of substorms and auroral power[J]. J. Geophys. Res., 2011, 116:A12211 [15] NAKAMURA R, BAKER D N, FAIRFIELD D H, et al. Plasma flow and magnetic field characteristics near the midtail neutral sheet[J]. J. Geophys. Res. Space Phys., 1994, 99(A12):23591-23601 [16] HSU T S, MCPHERRON R L. Occurrence frequency of substorm field and plasma signatures observed near-earth by ISEE-1/2[R]//Proceedings of Third International Conference on Substorms (ICS-3). Versailles: European Space Agency, 1996 [17] HSU T S, MCPHERRON R L. The Main Onset of a Magnetospheric Substorm[R]//Proceedings of Fourth International Conference on Substorms (ICS-4). Tokyo: Terra Science, 1998 [18] MILAN S E, GROCOTT A, HUBERT B. A superposed epoch analysis of auroral evolution during substorms: local time of onset region[J]. J. Geophys. Res. Space Phys., 2010, 115(A5):A00I04 [19] SUN W J, SLAVIN J A, FU S, et al. MESSENGER observations of magnetospheric substorm activity in Mercuryüs near magnetotail[J]. Geophys. Res. Lett., 2015, 42(10):3692-3699 [20] KISSINGER J, MCPHERRON R L, HSU T S, et al. Necessity of substorm expansions in the initiation of steady magnetospheric convection[J]. Geophys. Res. Lett., 2012, 39(15):51-60 [21] LI Kejun, FENG Wen, LIANG Hongfei. The abnormal 24th solar cycle-The first complete solar cycle of the new millennium[J]. Sci. Sin.: Phys. Mech. Astron., 2010, 40(10):1293-1301 [22] LUI A T Y. What deter mines the intensity of magnetospheric substorms[J]. J. Atmosph. Terr. Phys., 1993, 55(8):1123-1136 [23] HSU T S, MCPHERRON R L. A statistical study of the relation of Pi2 and plasma flows in the tail[J]. J. Geophys. Res., 2007, 112:A05209 [24] HSU T S, AND MCPHERRON R L. A statistical analysis of substorm associated tail activity[J]. Adv. Space Res., 2012, 50(10):1317-1343 [25] HSU T S, MCPHERRON R L, ANGELOPOULOS V, et al. A statistical analysis of the association between fast plasma flows and Pi2 pulsations[J]. J. Geophys. Res., 2012, 117:A11221
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