Winners announced for the Space Weather Competition. Visit for details.

The Magnetic Environment of a Stealth CME

Jennifer O'Kane - Mullard Space Science Laboratory, UCL, United Kingdom; Cecilia Mac Cormack - Instituto de Astronoma y Fsica del Espacio (IAFE), Argentina; Cristina Mandrini - Instituto de Astronoma y Fsica del Espacio (IAFE), Argentina; Lucie Green - Mullard Space Science Laboratory, UCL, United Kingdom; David Long - Mullard Space Science Laboratory, UCL, United Kingdom; Pascal Demoulin - LESIA, Observatoire de Paris, France; Gherardo Valori - Mullard Space Science Laboratory, UCL, United Kingdom

Session: The solar sources of space weather


Stealth coronal mass ejections (CMEs) are becoming of increasing interest due to their relatively high occurrence rate and space weather impact. Stealth CMEs are known for their extremely weak CME signatures, such as EUV dimmings and post-eruptive arcades, and require extensive image processing techniques in order to reveal these signatures and locate their source region. Consequently, little is currently understood about the physics of these events. We present an extensive study of the magnetic field configuration in which the stealth CME of 3 March 2011 occurred. The magnetic field prior to the eruption is evaluated using a linear force free field (LFFF) model and a potential field source surface (PFSS) model. These models are complemented and verified by in-depth observational analysis, i.e., plasma emission structures in the stealth CME source region. We find evidence of a coronal null point in the PFSS model, with surrounding field lines connecting the stealth CME source region to an active region in the northern hemisphere. We conclude that reconnection at the null point, driven by eruptive activity in the northern hemisphere active region, aids the eruption of the stealth CME by removing field that acted to stabilise the pre-eruptive structure.

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