The properties of geo-effective CMEs and SIRs in STEREO and THEMIS

We present a statistical study of stream interactions and CME events from January 2007 to August 2010 which result in storm and substorm activity. During this solar minimum the decrease in solar activity has resulted in less geomagnetic activity. The observed activity, which ultimately arises from changes in the solar wind, has been from stream interactions regions (SIRs), shocks, and some interplanetary coronal mass ejections (ICMEs). Geomagnetic activity is characterized by indices derived from ground based magnetometers. For each geomagnetic event, we indentified CMEs in the STEREO SECCHI coronagraphs, and SIRs in the STEREO SECCHI Heliospheric Imagers. Subsequent CME and/or SIR signatures were indentified in ACE, WIND, THEMIS, and any other available in-situ data. CME evolution in the lower corona and properties such as acceleration, speed and width were determined along with the in-situ plasma data for ICMEs. The propagation of these structures were tracked in the STEREO Heliospheric Imagers and subsequently in-situ. Geoeffectiveness, the strength and duration of geomagnetic activity, is compared with upstream solar wind conditions. For the 2007-2009 period, the most geoeffective storm events resulted from a combined CME and SIR interaction. ICMEs produced about 80% of the moderate storms, and SIRs produced 60% of the smaller storm events.