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In this paper we present results of a comparison between ultra low frequency (ULF) electromagnetic (EM) radiation, recorded by an electric field instrument (ICE) onboard the satellite DEMETER in the topside ionosphere, and the seismicity of regions with high and lower seiismic activity. In particular we evaluated the energy variations of the ULF Ez-electric field component during a period of four years (2006-2009), in order to examine check the possible relation of ULF EM radiation with seismogenic regions located in central America, Indonesia, Eastern Mediterranean Basin and Greece. As a tool of evaluating the ULF Ez energy variations we used Singular Spectrum Analysis (SSA) techniques. The results of our analysis clearly show a significant increase of the ULF EM energy emmited from regions of highest seismic activity at the tectonic plates boundaries. We interpret these results as suggesting that the highest ULF EM energy detected in the topside ionosphere is originated from seismic processes within Earth's crust. We understand the results of the present study as confirming previous evidence that the ULF EM anomalous wave activity in the ionosphere can be considered a useful earthquake precursory signal, Comment: 17 pages, PDF, Submitted for publication in Natural Hazards and Earth System Sciences

Ulysses investigated the high latitude Jovian magnetosphere for a second time after Pioneer 11 mission and gave us the opportunity to search the structure and the dynamics of this giant magnetosphere above the magnetodisc. Kivelson(1976) and Kennel & Coroniti(1979) reported that Pioneer 11 observed energetic particle intensities at high latitudes at the same level with those measured in the plasma sheet and inferred that they were not consistent with the magnetodisc model. Ulysses observations supported the idea about a large-scale layer of energetic ions and electrons in the outer high latitude Jovian magnetosphere (Cowley et al.1996; Anagnostopoulos et al. 2001). This study perform a number of further tests for the existence of the large scale layer of energetic ions in the outer high latitude Jovian magnetosphere by studying appropriate cross-B field anisotropies in order to monitor the ion northward/southward intensity gradients. In particular, we examined Ulysses/HI-SCALE observations of energetic ions with large gyro-radius (0.5-1.6MeV protons and >2.5MeV heavy(Z>5) ions) in order to compare instant intensity changes with remote sensing intensity gradients. Our analysis confirms the existence of an energetic particle layer in the north hemisphere, during the inbound trajectory of Ulysses traveling at moderate latitudes, and in the south high-latitude duskside magnetosphere, during the outbound segment of the spacecraft trajectory. Our Ulysses/HI-SCALE data analysis also provides evidence for the detection of an energetic proton magnetopause boundary layer during the outbound trajectory of the spacecraft. During Ulysses flyby of Jupiter the almost permanent appearance of alternative northward and southward intensity gradients suggests that the high latitude layer appeared to be a third major area of energetic particles, which coexisted with the radiation belts and the magnetodisc., Comment: 37 pages, 11 figures, 1 table

This paper brings space weather prediction close to earthquake (EQ) prediction research. The results of this paper support conclusions of previously presented statistical studies that solar activity influences the seismic activity, this influence is mediated through rapid geomagnetic disturbances and the geomagnetic disturbances are related with increases of solar wind speed. Our study concern an example of 40 days with direct response of a series of 7 strong-to-giant (M=6.8-9.3) EQs (including the Andaman-Sumatra EQ) to solar wind speed increases and subsequent geomagnetic fast disturbances. Our analysis for 10 M>6 EQs from November 23 to December 28, 2004 suggests a mean time response delay of EQs to fast geomagnetic disturbances of ~1.5 days. The two giant EQs during this period occurred after the two fastest geomagnetic variations, as revealed by the ratio of the daily Kp index variation over a day {\Delta}Kp/{\Delta}t (12 and 15, respectively). It suggests that the fast disturbance of the magnetosphere, as a result of the solar wind speed increase, is a key parameter in a related space weather-earthquake prediction research. The Solar-magnetosphere-lithosphere coupling and their possible special characteristics during the period examined needs further investigation, since it could provide significant information on the underlying physical relation processes of strong earthquakes., Comment: 26 pages, 8 figures

In this article we present examples of a wider study of space-time correlation of electron precipitation event of the Van Allen belts with the position and time of occurrence of strong (M>6.5) earthquakes. The study is based on the analysis of observations of electron bursts (EBs) with energies 70 - 2350 keV at middle geographic latitudes, which were detected by DEMETER satellite (at an altitude of ~700 km). The EBs show a relative peak-to-background increase usually < 100, they have a time duration ~0.5 - 3 min, energy spectrum with peaks moving in higher energies as the satellite moves towards the equator, and highest energy limit <~500 keV. The EBs are observed in the presence of VLF waves. The flux-time profile of the EBs varies in East Asia and Mediterranean Sea at the similar geographic latitudes, due to the differentiation of the magnitude of the earth's magnetic field. The most important result of our study is the characteristic temporal variation of electron precipitation variation which begins with incremental rate several days / a few weeks before major earthquakes, then presents a maximum, and finally become weaker, with a minimun or a pause of the electron precipitation some hours before the onset of the earthquake., Comment: 23 pages, 17 figures

In this paper we study the energy of ULF electromagnetic waves that have been recorded by the satellite DEMETER, during its passing over Haiti before and after a destructive earthquake. This earthquake occurred on 12/1/2010, at geographic Latitude 18.46o and Longitude 287.47o, with Magnitude 7.0 R. Specifically, we are focusing on the variations of energy of Ez-electric field component concerning a time period of 100 days before and 50 days after the strong earthquake. In order to study these variations, we developed a novel method that can be divided in two stages: first we filter the signal keeping only the very low frequencies and afterwards we eliminate its trend using techniques of Singular Spectrum Analysis, combined with a third-degree polynomial filter. As it is shown, a significant increase in energy is observed for the time interval of 30 days before the strong earthquake. This result clearly indicates that the change in the energy of ULF electromagnetic waves could be related to strong precursory earthquake phenomena. Moreover, changes in energy were also observed 25 days after the strong earthquake associated with strong aftershock activity. Finally, we present results concerning the comparison in changes in Energy during night and day passes of the satellite over Haiti, which showed differences in the mean energy values, but similar results as far as the rate of energy change is concerned., Comment: 16 pages, 7 figures, submitted to NHESS