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Differences between Forbush decreases originated by ICMEs and SIRs.

Christian Nicolas Gutierrez - Universidad de Buenos Aires; Sergio Dasso - Universidad de Buenos Aires, Argentina

Session: Interplanetary CMEs and Solar Particle Events


Interplanetary Coronal Mass Ejections (ICMEs) are the interplanetary manifestation of mass ejections from the solar corona. Stream Interaction Regions (SIRs) are interplanetary plasma resulting as consequence of the interaction between fast and slow solar wind. It is well known that ICMEs and SIRs are potential drivers of Forbush decreases (FDs), which consist in sudden decreases of the galactic cosmic rays flux observed at ground level, for instance by neutron monitors.

We study here a large number of ICMEs and SIRs from well ranked catalogues, analyzing solar wind properties from MAG and SWEPAM instruments aboard the ACE spacecraft with a time cadence of 16 and 64 seconds respectively, and GCRs data from MacMurdo neutron monitor with a time cadence of 1 hour. The aim of this study is to demonstrate the differences in FD properties (as for instance the shape of the flux profile decrease, the amplitude, and the recovery time) resulting from different kind of ICMEs and SIRs. Results presented in this work will help to better understand the physical mechanisms involved in the shielding of cosmic rays presented by these transient solar wind structures, as well as to improve the use of ground cosmic rays detectors in Space Weather.

Approaching deadlines:

Registration opens:

16 July 2020

Abstract submission opens:

16 July 2020

European Space Weather Medals:

6 September 2020

Registration deadline:

25 September 2020

Registration deadline: [extended]

10 October 2020

Abstract submission deadline:

4 September 2020