OBJECTIVES AND GOALS: OUR PRIMARY GOAL IS TO CONDUCT GROUND-BASED OBSERVATIONS OF MERCURY S EXOSPHERE THAT BUILD UPON THE LEGACY OF PREVIOUS OBSERVATIONS AND THE MESSENGER MISSION. SPECIFICALLY WE WILL FOCUS ON TWO OBJECTIVES: 1) CONTINUE OUR ONGOING GROUNDBASED MEASUREMENTS OF NA CA AND K TO PROVIDE LONG-TERM CONTEXT AND 2) OBSERVE SPECIES THAT ARE EITHER LESS ABUNDANT OR WEAKLY EMITTING SUCH AS AL FE MN AND CA+ TO EXPAND UPON THE MESSENGER DETECTIONS. LONG-TERM OBSERVATIONS MUST CONTINUE IN ORDER TO PLACE BOTH MESSENGER AND FUTURE BEPI-COLOMBO OBSERVATIONS INTO THE PROPER CONTEXT AND TO UNDERSTAND THE EXOSPHERE S RESPONSE TO SOLAR-CYCLE AND SEASONAL VARIATIONS. AT THE SAME TIME FOLLOW-ON OBSERVATIONS ARE NEEDED FOR OTHER SPECIES IN MERCURY S EXOSPHERE AND TO UNDERSTAND THE DISTRIBUTIONS OF ALL SPECIES AS REVEALED BY MESSENGER. THE UVVS INSTRUMENT ONBOARD MESSENGER DISCOVERED MN OBSERVED AL AND CA+ ON SEVERAL OCCASIONS AND PROVIDED INTRIGUING HINTS OF NON-UNIFORM SPATIAL DISTRIBUTIONS IN ALL SPECIES IT OBSERVED. UNFORTUNATELY LIMITATIONS ON THE MESSENGER ORBIT AND UVVS OBSERVING GEOMETRIES PRECLUDED ANY SIMULTANEOUS GLOBAL OBSERVATIONS SO THE DISTRIBUTIONS WERE ONLY PARTLY SAMPLED. MODERN SPECTROSCOPIC INSTRUMENTS ON THE GROUND HOWEVER EXCEL BY PROVIDING SYNOPTIC DATA ON THE EXOSPHERE. BRIGHT NA AND K EMISSIONS PROBE THE CONNECTION BETWEEN THE MAGNETOSPHERE AND THE INHOMOGENEOUS SURFACE EXHIBITING HIGH LATITUDE CHANGES ON SHORT-TIMESCALES. THESE HAVE PROVED DIFFICULT FOR MESSENGER TO RESOLVE OR IN THE CASE OF K DETECT. AS DEMONSTRATED BY BIDA AND KILLEN (2016) USING HIRES AT KECK 1 EVEN THE WEAKER SPECIES SUCH AS AL AND FE CAN BE OBSERVED FROM THE GROUND NOW AND OPTIMIZING THE OBSERVATION PLANS BASED ON MESSENGER DATA WILL ENABLE BETTER MEASUREMENTS.