Authors: Joan Burkepile (NCAR/High Altitude Observatory), Michael Galloy (NCAR/High Altitude Observatory) , Chris St. Cyr (Goddard Space Flight Center ,retired), Ian Richardson (Goddard Space Flight Center)

Solar energetic particle (SEPs) are highly energized protons, ions and electrons from the Sun moving at relativistic speeds. They pose radiation hazards to astronauts, aircraft crews, and satellites, and impact airline, Dept. of Defense, and HF radio communications. SEP events are strongly correlated with fast CMEs.  We use the NCAR Mauna Loa Solar Observatory (MLSO) COSMO K-Coronagraph (K-Cor) high cadence (15 sec) observations of the low and middle corona in polarized white light to track the properties of CMEs from near onset into the middle corona. K-Cor observes the coronal heights (1 to 3 solar radii) where CME acceleration is greatest. EUV observations are used to locate and track the CME from onset into the K-Cor field-of-view.  We use the Richardson catalog of SEP events since 2006 with proton energies  >= 25 MeV detected  in the ERNE and COSTEP instruments on SOHO and the HET instruments on STEREO A and B. One additional event is included that was detected by Solar Orbiter.  33 of these SEP events occurred during times when K-Cor was observing. Of these 33 CMEs: 30 were visible in K-Cor, and 3 were too faint to be detected by K-Cor.

We present the properties of the 30 CMEs visible in KCor, their corresponding properties higher in the corona seen in LASCO, the SEP fluxes, and X-ray flare intensities. We use the timing of the associated interplanetary Type II and Type III radio bursts to provide insights into the timing of the formation of the CME-driven shock.

REFERENCE:    Richardson catalog:  https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/GQPCX