Source region identification and geophysical effects of stealth coronal mass ejections

Abstract

We use the example of two Stealth-type coronal mass ejections (stealth CMEs) registered by LASCO C2 on the quiescent Sun on 16 June 2010 and in the active region NOAA 11520 7 July 2012 to demonstrate that these mass ejections emerged in a lower-coronal area where an intense short-term radiation burst was registered in several extreme ultraviolet channels. It is established for the first time that the stealth CME emergence is accompanied by an eruption of small-scale loop-like structures, and the frontal structure (FS) formation is detected. The time dependences of the velocity of these FSs are discussed. The conclusion is made that having reached Earth orbit and impacting on the Earth magnetosphere, the stealth CMEs can lead to magnetic substorm generation.