Typical Profile and Density peaks in Magnetic Clouds at 1 AU

RODRIGUEZ L.; ZHUKOV, A. N.; DASSO, S.; KILPUA, E.; MIERLA, M.

Moscow

Congreso; 40th COSPAR Scientific Assembly; 2014

COSPAR

Magnetic clouds (MCs) are a subset of interplanetary coronal mass ejections (ICMEs). They are important due to their internal magnetic field configuration, which resembles a magnetic flux rope, and because they represent the most geoeffective type of solar transients. In this study, we analyze their internal structure using a superposed epoch method of a large set of events (63) detected at L1 by ACE, between 1998 and 2006. We compare their internal parameters with those seen in the solar wind and with respect to the solar cycle variation. In particular, we are interested in the density increase seen at the trailing part of some magnetic clouds. Furthermore, we link events with their solar counterparts and compare the remote observations in EUV and white-light with the in situ data. We find three possible causes for these density peaks: Filament material, compression from a trailing fast speed stream, expansion of the cloud. We discuss the implications of these three mechanisms.