Physics of auroral phenomena : proceedings of the 36th Annual seminar, Apatity, 26 February – 01 March, 2013 / [ed. board: A. G. Yahnin, A. A. Mochalov]. - Апатиты : Издательство Кольского научного центра РАН, 2013. - 215 с. : ил., табл.

Common features o f GLEs in 19-24 solar cycles Discussion The list of studied events includes GLEs very different in amplitude, duration, and rigidity. There are both giant (GLE05, GLE69) and weak (GLE26, GLE40, GLE50) events. Events GLE05 and GLE42 are the most rigid; events GLE 19 and GLE39 are very short, about half an hour. However, as the table shows, the most o f GLE (~80%) consists of two components, called prompt and delayed. These components have different both energy and spatial parameters. The spectral function of the prompt component (PC) is exponential. The delayed component (DC) has a power law spectrum. The prompt component always has a high degree o f anisotropy; the width o f the flux does not exceed 60-70 degrees and at angles >90 the flux is completely absent. The delayed component is close to isotropic. On the growth phase (and at the maximumin in large events) RSP flux consists o f PC. DC appears after the maximum and persists until the end of the event. The dynamics of the spectra (they are calculated in steps of 5 minutes) shows a smooth transition from one form of the spectrum to the other for 15-30 minutes. A small number o f events consist o f a single component. PC is absent in those GLE events which originate from the flare behind the Sun limb. Two events (GLE36 and GLE71) have no DC. Table 1 GLE Inc. Prompt com Delay com GLE Inc. Prompt com Delay com № % Jo E0 Ji -у № % Jo E0 Ji -Y 05 5117 7.4-105 1.37 5.5T05 4.6 39 96 - - 5.2T04 5.9 08 253 2.710s 0.65 1.6103 4.2 40 6 2.2-102 1.15 5.8-10^ 4.4 10 144 - - 7.5103 4.5* 41 15 6.8-10J 0.56 3.8- 10J 5.1 11 111 - - 1.0-105 5.3 42 392 1.5-104 1.74 2.5-104 4.1 13 18 5.2-103 0.52 3.6-103 6.0 43 49 4.0-104 0.53 3.0-104 4.8 16 19 1.4104 0.58 6.7-10J 4.7 44 154 7.5-104 0.91 1.5-104 6.1 19 12 1.2T04 0.58 2.6103 5.5 45 114 2.4-104 0.72 1.1-10* 4.9 20 15 6.2104 0.47 4.6103 5.1 46 23 6.3-103 1.13 2.7- 10J 4.3 21 7 - - 7.4-10" 4.4’ 48 43 2.8-104 0.60 9.1-10J 4.3 22 28 3.4T04 0.45 о oo 5.8 49 8 - - 9.0-10J 4.7 23 12 - - 3.7-10 5.1" 51 8 2.6-10J 0.83 3.3-10J 4.8 24 36 - - 1.5T0J 7.1 52 26 - - 5.8- 10J 4.6 25 8 6.6-102 1.23 4.3-102 5.0 55 11 8.3-10J 0.92 8.2- 10J 4.6 26 5 3.7-103 0.51 - - 59 40 3.3-105 0.50 5.ОТО4 5.4 27 13 6.6-105 0.32 6.7103 5.7 60 123 1.3-105 0.62 3.5-104 5.3 28 4 2.2-104 0.48 3.3-10" 4.8 61 15 2.5T04 0.52 1.2- 10J 3.6 29 9 6.5-10' 1.14 9.3-102 3.2 65 43 1.2-104 0.60 1.5-104 4.4 30 33 1.5-104 0.77 1.1-104 4.7 67 16 4.6-104 0.51 9 .7103 6.3 31 208 3.5T04 1.11 1.3-104 4.0 69 2751 2.5-106 0.49 7.2-104 5.6 32 8 1.5T04 0.41 7.ОТО'* 4.7 70 93 3.5-104 0.59’" 4.3-104 5.7 36 9 4.5T04 1.21 - - 71 18 1.5-105 0.34 . _ 38 54 5.7-10J 0.65 7.2103 4.5 * - from hourly data ** - approximation, real spectrum isn’t pure power law *** - approx., real spectrum isn’t pure exponent The exponential spectrum shape of the PC indicates that the particles o f this flux were accelerated in an electric field. Only this type of acceleration gives such spectrum. Electric fields can be generated during magnetic reconnection in the active region on the Sun. For more details see [7, 8]. PC particles are emitted immediately from the Sun along the open field lines and reach the Earth first. The Fig. 2 shows the spectra of PC and DC of all the events listed in the table. DC spectra clearly grouped into two subsets. The first set has a hard spectrum with a value of g ~ 4, the second one has a soft spectrum with g ~ 6. PC spectra are located different. Most of the spectra are in a group that has the characteristic energy E0 ~ 0 45-0 65 GeV. Spectra with the value o f E0 > 0.9 GeV are in a small scattered group. It includes PC spectra o f outstanding events GLE05, GLE42, GLE69. In our previous work [9] it was found that, due to specific NM sensitivity huge NM increase can be produced at low intensity J0 of PC. To produce -1000% NM increase, DC should have intensity J, around two magnitude orders higher than usual, but direct measurements in the stratosphere and on the spacecrafts do not reveal such intensity. 108