Naslov
Forbush decreases associated to stealth coronal mass ejections

Autori
Heber, B. ; Wallmann, C. ; Galsdorf, D. ; Herbst, K. ; Kühl, P. ; Dumbović, Mateja ; Vršnak, Bojan ; Veronig, A. ; Temmer, M. ; Möstl, C. ; Dalla, S.

Izvornik
Central European astrophysical bulletin (1845-8319) 39 (2015), 1; 75-82

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Galactic Cosmic Rays ; Forbush decreases ; Stealth CMEs

Sažetak
Interplanetary coronal mass ejections (ICMEs) are structures in the solar wind that are the counterparts of coronal mass ejections (CMEs) at the Sun. It is commonly believed that enhanced magnetic fields in interplanetary shocks and solar ejecta as well as the increased turbulence in the solar wind sheath region are the cause of Forbush decreases (FDs) representing decreases of galactic cosmic ray (GCR) intensities. Recently, stealth CMEs i.e. CMEs with no apparent solar surface association have become a subject in recent studies of solar activity. Whether all of such stealth CMEs can drive a FD is difficult to investigate on the basis of neutron monitor NM measurements because these measurements not only reflect the GCR intensity variation in interplanetary space but also the variation of the geomagnetic field as well as the conditions in the Earth atmosphere. Single detector counter from spacecraft instrumentation, here SOHO and Chandra EPHIN, exceed counting statistic of NMs allowing to determine intensity variation of less than 1h in interplanetary space on the basis of 30 minute count rate averages. Here we present the ongoing analysis of eleven stealth CMEs.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

POVEZANOST RADA