Correlated Measurements of the Disturbances of Geomagnetic Field and Changes of Secondary Particle Fluxes at Aragats-Space Environmental Center (ASEC)
Final rept. 1 Jan-31 Dec 2009
ALIKHANYAN PHYSICS INST ARMENIA (YEREVAN)
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Our objective is the development of a geomagnetic storms forecast service. It will consists of a observed solar bursts data, particle detector data and current geomagnetic activity data. They originate in solar activity and variability of many different forms including solar flares, coronal mass ejections, solar wind sector boundaries and coronal hole streams. Variations of geomagnetic field can adversely affect any technical systems which rely on local magnetic field measurements to be taken in the absence of significant geomagnetic variations. Users who are unaware of and thus unprepared for the imminent occurrence of major magnetic field disturbances may conduct operations which later turn out to have been useless and eventually a waste of time and resources. Our project attempts to address geomagnetic storm forecasting by developing a service which gives advance notice of increasing geomagnetic activity and thus enables the affected users to plan and conduct their operations in a more cost-effective way. Information on flux changes for different secondary particles helps to test Interplanetary Magnetic Fields IMF and magnetosphere for understanding of the level of disturbance and specific mechanisms leading to cutoff rigidity reduction. Our observations of the GMS occurred during 23rd Solar activity cycle demonstrate that Cosmic Ray increase during GMS occurs coherently or approx. 1 hour in advance with abrupt changes of the geomagnetic field, sized up by Dst index. To test geomagnetic disturbances models and provide a valuable user-oriented forecast, it is not sufficient to have only global geomagnetic indices. Several studies demonstrate that local geomagnetic indices are better correlated with consequences of severe GMS. Unfortunately in the radius of 1000 km. from mt. Aragats there are no permanently operating geomagnetic observatories or magneto-telluric stations.