The 24-th Solar Activity Cycle Produce the First Violent Blast: Now Ramping up Toward a Solar Maximum in 2013.
Prof. Ashot Chilingarian
Director of Yerevan Physics Institute
Head of the Cosmic ray division
March 2, 2011
The Cosmic Ray Division (CRD) of the Yerevan Physics Institute registered the first violent solar eruption of the 24th Solar Cycle on its cosmic ray monitoring.
The sun unleashed its strongest solar flare in nearly five years on Feb 15, 2011, sending a massive wave of charged particles toward Earth. The Coronal Mass Ejection (CME), a huge cloud of charged particles, reached the earth in approximately 3 days triggering a sizeable geomagnetic storm and a deep Forbush decrease (Fd). Fd is a rapid decrease in observed galactic cosmic ray intensity following a CME arrival. A variety of cosmic ray particle detectors at the Aragats Space Environmental Center (ASEC) in Armenia and the Space Environmental Viewing and Analysis Network (SEVAN), a worldwide network, registered the Fd in minute detail.
 Figure 1. Pressure corrected time series of ASEC particle monitors |
 Figure 2. Pressure corrected time series of SEVAN particle monitors |
Figure 1 shows the intensity variation of the neutral and charged particles measured on Mt. Aragats at 3200 m above sea level. Figure 2 demonstrates the first results from the SEVAN detectors in Armenia, Bulgaria and Croatia, registering Fd simultaneously. The data from monitors located at different longitudes, latitudes and altitudes allows us to untangle solar- terrestrial connections and test simulations of fast solar wind interaction with the magnetosphere.