The link between CME-associated dimmings and the interplanetary magnetic clouds

MANDRINI, C.H.; NAKWACKI, M.S.; ATTRILL, G.; VAN DRIEL-GESZTELYI, L.; DASSO, S.; DEMOULIN, P.

Ioannina, Grecia

Simposio; IAU Symposium No. 257 Universal Heliophysical Processes; 2008

International Astronomical Union (IAU)

Coronal dimmings often develop in the vicinity of erupting magnetic configurations.It has been suggested that they mark the location of the footpoints of ejected flux ropes and,thus, their magnetic flux can be used as a proxy for the ejected flux. If so, this quantity can becompared to the flux in the associated interplanetary magnetic cloud (MC) to find clues aboutthe origin of the ejected flux rope. In the context of this interpretation, we present several eventsfor which we have done a comparative solar-interplanetary analysis.We combine SOHO/ExtremeUltraviolet Imaging Telescope (EIT) data and Michelson Doppler Imager magnetic maps toidentify and measure the flux in the dimmed regions.We model the associated MCs and computetheir magnetic flux using in situ observations. We find that the magnetic fluxes in the dimmingsand MCs are compatible in some events; though this is not the case for large-scale and intenseeruptions that occur in regions that are not isolated from others. We conclude that, in theseparticular cases, a fraction of the dimmed regions could be formed by reconnection between theerupting field and the surrounding magnetic structures, via a stepping process that can explainother CME associated events.