2009-07-22 14:04:13

Magnetometric Measurements started in Armenia

Magnetometric station LEMI-417, commissioned by Lviv center of Space Research Institute of Ukrainian Academy of Sciences, was installed in Nor Amberd (the same type of station with added electrical field sensors will be installed in Aragats in September, 3200 above sea level). See in Figure 1 the first Geomagnetic  Storm on  July 22, detected  in Nor Amberd,  in comparison with DST index (other averaged magnetomerters located in middle-low latitudes). Geomagnetic activity increased to major storm levels from 0300 - 1200 UTC on July 22. Activity decreased to quite unsettled levels for the remainder of the day and continued through  July 25. Activity decreased to quite unsettled levels at all latitudes on  July 26. ACE solar wind measurements indicated that the storm conditions on July 22 were associated with the onset of a coronal hole high-speed wind stream. Solar wind velocities began to gradually increase early on July 22 and eventually reached a maximum of 601 km/sec at 24/0158 UTC. Velocities gradually decreased during the rest of the period. Interplanetary magnetic  field (IMF) changes, associated with the onset of the high-speed stream, included an increase in IMF Bt (peak 18 nT at 22/0533 UTC) and a sustained period of southward IMF Bz (minimum -18 nT at 22/0703 UTC).

Figure 1 Comparison of the geomagnetic storm, detected by the new facility in Nor Amberd and DST index calculated by Kyoto magnetic observatory (DST is measured in relative units; Nor Amberd magnetometer – in absolute)

One-minute time series of the 3-dimensional measurements of the geomagnetic field will enter data base of the Aragats Space Environmental Center (ASEC) and will highly improve research of correlations of the geomagnetic parameters and changes of the fluxes of cosmic rays now underway at Aragats. ASEC measures neutral and charged fluxes of secondary cosmic rays (Chilingarian et.al. 2005); correlations of changes of these fluxes with geomagnetic parameters and Interplanetary Magnetic Field (IMF) parameters measured by facilities of the ACE space station located 1.5 mln. km from  Earth will assist to understand Solar influence on the Earth environments (see, for instance Bostanjyan & Chilingarian, 2009). Measurements of geomagnetic field from Nor Amberd will support forewarning of the upcoming major geomagnetic storm to be started by CRD in 2010.

Chilingarian  A., et al., Correlated measurements of secondary cosmic ray fluxes by the Aragats Space – Environmental Center monitors, Nucl. Instrum. Methods Phys. Res.,  A543, 483-496, 2005.

N. Bostanjyan, A.Chilingarian,  Cosmic Ray Intensity increases detected by ASEC monitors during the 23rd solar activity cycle in correlation with Geomagnetic storms, Journal of Geophysical Research, 2009, in press.