MOTIVATION: THE CURRENT SOLAR CYCLE IS UNIQUE IN THAT LEVELS OF ACTIVITY ARE THE LOWEST FOR ANY CYCLE SINCE THE SPACE AGE IN TERMS OF A SHORTAGE OF LARGE FAST CORONAL MASS EJECTIONS (CMES) AND HIGH-ENERGY PARTICLE EVENTS (E.G. GROUND-LEVEL EVENTS (GLES)). THIS LOW LEVEL OF ACTIVITY HAS BROUGHT ABOUT UNIQUE CHALLENGES. ONE OF THESE IS THE RISE IN STEALTH CMES WHICH ARE CMES OBSERVED IN CORONAGRAPH DATA BUT NOT IN CORONAL IMAGES ESPECIALLY IN DISK VIEW. THESE EVENTS WERE IDENTIFIED DURING THE DEEP MINIMUM OF CYCLE 23/24 AND APPEAR TO BE INCREASING. FAR FROM LACKING IMPACT THESE NEAR-INVISIBLE STEALTH CMES HAVE BEEN LINKED TO MODERATE GEOMAGNETIC STORM ACTIVITY (KILPUA ET AL. 2014). UNFORTUNATELY WITH MODERATE GEOMAGNETIC STORMS FROM UNSEEN SOURCES ALSO ON THE RISE IT HAS BECOME EMBARRASSINGLY OBVIOUS THAT OUR FIELD CURRENTLY LACKS THE CAPABILITY TO IDENTIFY AND ACCURATELY PREDICT THE EFFECTS OF STEALTH CMES AT EARTH. SINCE SOLAR CYCLE 25 BRINGS POSSIBLY ANOTHER LOW ACTIVITY CYCLE THE NUMBER OF STEALTH CMES WILL LIKELY REMAIN A SIGNIFICANT FRACTION OF EJECTA. THUS A BETTER UNDERSTANDING OF THEIR ERUPTION MECHANISMS THE TIMESCALE OVER WHICH ON-DISK OBSERVATIONS MUST BE MADE AND A RELIABLE ASSOCIATION WITH ICME EVENTS AT 1 AU ARE OF PARAMOUNT IMPORTANCE TO SPACE WEATHER PREDICTION. WE PROPOSE A 3- YEAR INVESTIGATION TO BETTER UNDERSTAND THE ORIGIN OF STEALTH CMES TO FIND THE LINK BETWEEN STEALTH CMES AND THEIR IN-SITU SIGNATURES AND TO DETERMINE HOW THE INTERACTION BETWEEN STEALTH CME ERUPTIONS CORONAL HOLES AND THE FAST SOLAR WIND OFTEN ENHANCES THE GEOEFFECTIVENESS OF THE RESULTING TRANSIENTS AT EARTH. OBJECTIVES: 1) CAN WE FIND ON-DISK SIGNATURES OF STEALTH CMES IN CORONAL IMAGES AFTER EXTENSIVE IMAGE PROCESSING? HOW DO THEY GET ACCELERATED? CAN WE TRACK THEM TO 1 AU USING PRESENTLY AVAILABLE DATA? 2) CAN A SUBSET OF STEALTH CMES RESULT FROM EXPANDING LOOPS AT THE EDGE OF ACTIVATED REGIONS AROUND CORONAL HOLES? DO SUCH EVENTS HAVE SUPRATHERMAL ELECTRON SIGNATURES IN SITU DISTINCT FROM THE OPEN FIELD TOPOLOGIES OF THE SOLAR WIND? 3) HOW DOES THE PROXIMITY OF STEALTH CMES TO CORONAL HOLES AFFECT THE EVOLUTION OF THESE TRANSIENTS IN THE SOLAR WIND? DOES A PARTICULAR GEOMETRY OF THE SOURCE REGION ALLOW GREATER INTERACTION BETWEEN THE CME AND FAST SOLAR WIND RESULTING IN A MORE GEOEFFECTIVE TRANSIENT? METHODOLOGY: OBJECTIVE 1) WE WILL IMPROVE ON-DISK DETECTION BY IMPROVING SIGNAL-TO-NOISE RATIO IN SDO/AIA IMAGES USING SPATIAL AND TEMPORAL SUMMATIONS AND ADJUSTING TIME SPANS OF DIFFERENCE AND RATIO IMAGES. THESE CHANGES WILL ALLOW US TO FOCUS ON SLOW FAINT SIGNATURES. WE WILL USE STEREO/SECCHI IMAGES WHEN STEREO WAS NEAR QUADRATURE (STEREO OBSERVES EARTH-DIRECTED EVENTS AS LIMB EVENTS) TO LINK CME STRUCTURES TO THEIR INTERPLANETARY COUNTERPARTS. OBJECTIVE 2) WE WILL INVESTIGATE STEALTH CMES/ICMES ORIGINATING FROM EXPANDING LOOPS AROUND CORONAL HOLES. WE WILL DETERMINE IF SUCH ICMES HAVE ELECTRON STRAHL SIGNATURES SIMILAR TO THOSE OUTLINED BY CROOKER ET AL. (2004). OBJECTIVE 3) STEALTH CMES GAIN SPEED DUE TO INTERACTION WITH AMBIENT SOLAR WIND BUT SOME ERUPTION GEOMETRIES ARE MORE CONDUCIVE TO ACCELERATION. CORRELATIONS BETWEEN STEALTH CMES ERUPTING IN CERTAIN LOCATIONS RELATIVE TO CORONAL HOLES AND SLOW ICMES IMPACTED BY FAST SOLAR WIND THAT INCREASE THEIR GEOEFFECTIVENESS WILL BE TESTED AGAINST EXPERIMENTAL GEOMETRIES USING SOLAR WIND AND MAGNETOSPHERIC MODELING. RELEVANCE: THIS PROPOSAL IS RELEVANT TO TWO DECADAL SURVEY SCIENCE GOALS (1) DETERMINE THE ORIGINS OF THE SUN S ACTIVITY AND PREDICT THE VARIATIONS IN THE SPACE ENVIRONMENT: WE AIM TO UNDERSTAND CMES WHICH ARE MANIFESTATIONS OF THE SUN S ACTIVITY CAUSING MAJOR VARIATIONS IN THE SPACE ENVIRONMENT. (4) DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE: WE FOCUS ON HOW COMMONLY SOLAR ERUPTIONS CAN BE TRIGGERED BY MAGNETIC RECONNECTION ONE OF THE FUNDAMENTAL PROCESSES IN THE UNIVERSE.