Signs of geoeffective space weather events in cosmic rays during the first half of the solar cycle 24

Solar originating events are continually evident in galactic cosmic ray (GCR) flux registered at the ground by neutron monitors. We analyze time intervals of sporadic Forbush decreases (Fd) observed by neutron monitors (NM) during the first half of solar cycle 24. We consider NMs data, as well as, solar, heliospheric and geoma - gnetic activity parameters, around those periods, using different mathematical tools. Subsequently, an impact of space weather phenomena on energy infrastructure is well known, in the further step we consider logs from one of the Polish transmission lines operators during the time intervals of Fds. Based on the data from the Ins- titute of Meteorology and Water Management-Polish National Research Institute we exclude from the analysis the weather-related failures. We found that the increase in the superposed averaged number of failures appears around Forbush decreases

On the relative equilibrium configurations in the planar five-body problem

The number of central configurations in the Grebenicov-Elmabsout model of the planar five-body problem is estimated. An appropriate rational parameterization is used to reduce the equations defining such configurations to some polynomial ones. For the restricted five-body problem a sharp estimation is given by using the Sturm separation theorem

On the relative equilibrium configurations in the planar five-body problem

Tyt. z nagłówka.Bibliogr. s. 504-505.Dostępny również w formie drukowanej.ABSTRACT: The number of central configurations in the Grebenicov-Elmabsout model of the planar five-body problem is estimated. An appropriate rational parameterization is used to reduce the equations defining such configurations to some polynomial ones. For the restricted five-body problem a sharp estimation is given by using the Sturm separation theorem. KEYWORDS: planar five-body problem, relative equilibrium, central configuration, Grebenicov-Elmabsout model

Evaluating the relationship between strong geomagnetic storms and electric grid failures in Poland using the geoelectric field as a GIC proxy

We study intense geomagnetic storms (Dst < −100nT) during the first half of the solar cycle 24. This type of storm appeared only a few times, mostly associated with southwardly directed heliospheric magnetic field Bz. Using various methods such as self-organizing maps, statistical and superposed epoch analysis, we show that during and right after intense geomagnetic storms, there is growth in the number of transmission line failures. We also examine the temporal changes in the number of failures during 2010-2014 and find that the growing linear tendency of electrical grid failure occurrence is possibly connected with solar activity. We compare these results with the geoelectric field calculated for the region of Poland using a 1-D layered conductivity Earth model