Abstract
In a recent paper McCracken et al. (J. Geophys. Res. 113:A12101, 2008) proposed that the Ground Level Enhancement (GLE) of 20 January 2005 may have been produced by more than one acceleration mechanism, with the first acceleration due to the solar flare and the second one due to the CME associated with that event. They also noted several other GLEs with similar multiple pulse structures. This paper systematically investigates all the GLEs of solar cycle 23, from GLE 55 on 6 November 1997 to GLE 70 on 13 December 2006, to study their morphology and pulse structure, and to determine whether the multiple structures that may be found in these events are qualitatively similar to that of the GLE of 20 January 2005. We use all the data of all NMs that saw each event, to have as much directional and spectral information as possible. It is shown that three of these 16 events do contain such double-pulse structures, and the properties of these three are discussed in some detail.
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References
R. Abbasi et al. (IceTop). Astrophys. J. 659, L65 (2008)
Y.V. Balabin, B.B. Gvozdevsky, E.V. Vashenyuk et al., in Proc. 30th ICRC, vol. 1, p. 257 (2007)
J.W. Bieber, W. Dröge, P. Evenson, R. Pyle, D. Ruffolo, U. Pinsook, P. Tooprakai, M. Rujiwarodom, T. Khumlumlert, S. Krucker, Astrophys. J. 567, 622 (2002)
J.W. Bieber, P. Evenson, W. Dröge, R. Pyle, D. Ruffolo, M. Rujiwarodom, P. Tooprakai, T. Khumlumlert, Astrophys. J. Lett. 601, L103 (2004)
J.W. Bieber, J.M. Clem, P.A. Evenson et al., in Proc. 30th ICRC, vol. 1, p. 229 (2007)
R.A. Caballero-Lopez, H. Moraal, F.B. McDonald, J. Geophys. Res. 109, A05105 (2004). doi:10.1029/2003JA010358
E.W. Cliver, in Proc. IAU Symp., vol. 257 (Cambridge Univ. Press, Cambridge, 2008), p. 401
N. Gopalswamy, H. Xie, S. Yashiro, I. Usoskin, Indian J. Radio Space Phys. 39(5), 240–248 (2010)
V.G. Grigoryev, S.A. Starodubtsev, P.A. Krivoshapkin et al., in Proc. 30th ICRC, vol. 1, p. 233 (2007)
J.R. Jokipii, Astrophys. J. 152, 997 (1968)
A.W. Labrador, R.A. Leske, R.A. Mewaldt, E.C. Stone, T.T. von Rosenvinge, in Proc. 29th ICRC, vol. 1, p. 99 (2005)
K.G. McCracken, H. Moraal, P.H. Stoker, J. Geophys. Res. 113, A12101 (2008). doi:10.1029/2007JA012829
R.A. Mewaldt, C.M.S. Cohen, G.M. Mason, A.C. Cummings, M.I. Desai, R.A. Leske, J. Raines, E.C. Stone, M.E. Wiedenbeck, T.T. von Rosenvinge, T.H. Zurbuchen, Space Sci. Rev. 130, 207 (2007). doi:10.1007/s11214-007-9187-1
H. Moraal, J.P.L. Reinecke, K.G. McCracken, in Proc. 31st ICRC, p. 1553 (2009)
C.K. Ng, D.V. Reames, Astrophys. J. 686, L123 (2008)
J. Ryan et al., Space. Sci. Rev. (2010, this issue)
A. Saiz, D. Ruffolo, J.W. Bieber, P. Evenson, R. Pyle, Astrophys. J. 672, 650 (2008)
D.A. Timashkov, Yu.V. Balabin, V.V. Borog et al., in Proc. 30th ICRC, vol. 1, p. 209 (2007)
A.J. Tylka et al., Astrophys. J. 625, 474 (2005)
E.V. Vashenyuk, G.A. Bazilevskaya, Y.V. Balabin et al., in Proc. 30th ICRC, vol. 1, p. 221 (2007)
T.T. Von Rosenvinge, H.V. Cane, in Geophysical Monograph, vol. 165, ed. by N. Gopalswamy et al. (American Geophysical Union, Washington, 2006), p. 103
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Moraal, H., McCracken, K.G. The Time Structure of Ground Level Enhancements in Solar Cycle 23. Space Sci Rev 171, 85–95 (2012). https://doi.org/10.1007/s11214-011-9742-7
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DOI: https://doi.org/10.1007/s11214-011-9742-7