The GRAPES-3 muon telescope in Ooty, India is the largest of its kind which provides multi-rigidity observation of galactic cosmic rays above 17 Giga-Volt with a field of view of 2.3 sr and directional resolution of 4 degree. Following GRAPES-3 discovery of a transient weakening of Earth’s magnetic shield through observation of a cosmic ray burst on 22 June 2015, I have been involved in an effort to search for more such events in 20 years of archived data. The development of a fast and efficient technique has allowed us to analyze the 22 June 2015 event in fraction of a second with same resolution as the earlier computational-intensive method which had required over two months of running time on the 1280 core GRAPES3 computer cluster in Ooty. The drastic reduction in computation time has allowed us to analyze 20 years of GRAPES-3 archival data resulting in identification of more than 70 such events. The detailed analysis of these events could address the problem of identifying the dependence of the arrival time delay as a function of geomagnetic storm parameters. This is extremely important for accurate prediction of geomagnetic storms, a challenging problem in space-weather research. The properties of a few such events will be discussed in the talk.
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Event calendar file
