Authors: Ian G. Richardson (UMd/GSFC), O. Chris. St. Cyr, (CUA/GSFC), Joan T. Burkepile (NCAR HAO), Barbara J. Thompson (GSFC)

We report on a study of coronal mass ejections (CMEs) associated with ≳25 MeV solar energetic proton (SEP) events in 1980-2013 observed in the low corona by the Mauna Loa Solar Observatory (MLSO) Mk3 and Mk4 coronagraphs, with cadences of 3 minutes and, where possible, combined with space-based observations from the SMM C/P, P78-1 Solwind or SOHO/LASCO coronagraphs. The aims of the study are to understand CME motions in the lower corona and their association with SEP acceleration, and hence attempt to identify early signatures characteristic of SEP acceleration in ground-based CME observations.  A major challenge turns out to be determining the CME velocity and acceleration in the low corona, since different techniques can produce inconsistent results.  This then complicates the assessment of whether observations of CMEs in the low corona may provide earlier predictions of an SEP event and its likely peak intensity than space based coronagraphs.