Coronal Mass Ejections during Cycle 24 (Invited)

The CMEs that are occurring during the current Cycle 24 are being observed by both the SOHO/LASCO and the two STEREO/SECCHI coronagraphs. Since 2009, the STEREO A and B spacecraft have moved from about 30 degrees from earth to their current positions of about 140 degrees. The unique configuration of STEREO and SOHO is enabling virtually all CMEs to be observed. Although the CMEs are generally less massive in this cycle, they are still producing geomagnetic storms. The STEREO observations have enabled the confirmation of a unique class of CMEs that are not associated with chromospheric signatures. This was suggested in the early 1980's with the P78-1/SOLWIND coronagraph and then later with the LASCO coronagraph, but the lack of low corona/chromospheric signatures could not be ruled out. This complicates the identification of a geomagnetic storm with a particular solar event. We will discuss the properties of the Cycle 24 CMEs and the 'stealth' CMEs. We acknowledge the support of NASA.