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Results of study of secondary electrons and positrons in the energy range 15–150 MeV in the earth space-orbit are reviewed.

In this paper, in order to figure out the variations before an earthquake and extract abnormal signals related to it, the geomagnetic three component Z, H, F minute values of 15 geomagnetic stations within 600km of the epicentral distance before the MS 6.6 Minxian–Zhangxian earthquake in Gansu were analyzed. The following are the results. (1) After the fractal analysis was used directly, only three geomagnetic stations in 15 geomagnetic stations showed synchronous anomalous signals; (2) After the method of this paper was used, 9 of the 15 geomagnetic stations (including the three stations in the first point) extracted two synchronous anomalous signals, and six of the nine geomagnetic stations presented additional synchronous anomalous signals. (3) Of the three abnormal signals extracted, one had a medium-term effect and two had short-term effects. (4) The anomalous duration of the Z component of nine geomagnetic stations was longer than that of H and F. And as the epicentral distance increased, duration decreased. While the proposed method could not clearly indicate the exact relationship between the anomalous signals and the earthquake, it was proved that the signals extracted are effective and well-correlative to the earthquake.

Strangelets coming from the interstellar medium are an interesting target in experiments searching for evidence of this hypothetic state of hadronic matter. For a stationary population of strangelets to be trapped by the geomagnetic field, these particles would have to fulfill certain conditions, namely having magnetic rigidities above the geomagnetic cutoff and below a certain threshold for adiabatic motion. For totally ionized strangelets these two conditions prevent them to be stably trapped if one considers that a similar mechanism resulting in the anomalous cosmic rays belt should also be responsible for strangelet trapping. The situation could be different if those particles could reach the earth with an effective charge less than total ionization, since it would lower the particle's magnetic rigidity, but cross sections are much too low to allow interstellar electronic recombination for strangelets in the low baryonic number range. If traces of strangelets are indeed measured as a component of the radiation belt, alternative methods for their capture have to be proposed.

A nonlinear forecasting analysis has been applied to the secular variation of the three-component annual means of 14 observatories, unevenly distributed over the Earth's surface (12 in the northern and 2 in the southern hemisphere) and spanning the last 150 years. All results were in agreement, either in terms of possible evidence of chaos (as opposed to the hypothesis of white or colored noise), or in terms of the Kolmogorov entropy, confirming previous results obtained with only three European observatories, i.e. it is practically impossible to predict the secular variation of the geomagnetic field more than six years into the future.

Results of study of secondary electrons and positrons in the energy range 15–150 MeV in the earth space-orbit are reviewed.

We developed a backtracing code for Cosmic Rays trajectory reconstruction in the Earth Magnetosphere with last models of Internal (IGRF-11) and External (Tsyganenko 1996 and 2005) field components. Particles can be reconstructed, in case of allowed trajectory, as Primary Cosmic Rays if they reach the outer boundary (magnetopause) or, in case of forbidden trajectory, as Secondary particles if they go back to the inner boundary. During the last solar active period (2011 and 2012) we compared backtracing results on AMS-02 proton and electron data with and without external field model. Using TS05, specifically designed for storm events, we confirmed the well known East-West effect. Moreover we clearly found the day night effect related to the asymmetric shape of the Magnetosphere if considering the External Field, in comparison with the Internal Field only.