WE PROPOSE TO ANALYZE NEW HORIZONS (NH) MVIC AND LEISA SPECTRAL SCANS OF PLUTO AND CHARON TOGETHER WITH DECADES OF GROUNDBASED VISIBLE AND NEAR-INFRARED SPECTROSCOPIC DATA OF THE SYSTEM USING A MODERN RADIATIVE TRANSFER CODE TO QUANTIFY THE SPATIAL DISTRIBUTION AND LONG TERM EVOLUTION OF PLUTO'S ICES. NASA S NEW HORIZONS (NH) MISSION HAS RECENTLY REVEALED THE COMPLEX CRYOGENIC WORLD OF PLUTO. THE STRIKING SPATIAL HETEROGENEITY ON THE SURFACE OF PLUTO RESULTS FROM A VARIETY OF GEOLOGIC AND ATMOSPHERIC PROCESSES INCLUDING THE SEASONAL TRANSPORT OF NITROGEN METHANE AND CARBON MONOXIDE ICES WHICH ARE VOLATILE AT THE TEMPERATURES PREVAILING ON PLUTO'S SURFACE. OVER SEASONAL TIMESCALES VARYING PATTERNS OF INSOLATION ARE THOUGHT TO CAUSE SUBLIMATION AND REDISTRIBUTION OF THESE VOLATILE ICES. SEVERAL EFFORTS HAVE BEEN UNDERTAKEN TO IMPROVE OUR UNDERSTANDING OF SURFACE-ATMOSPHERE INTERACTIONS AND SEASONAL CHANGES ON PLUTO. HOWEVER UP UNTIL NOW THERE IS NO QUANTITATIVE UNDERSTANDING OF HOW THE SUBLIMATION AND CONDENSATION OF PLUTO S VOLATILE ICES MODIFY THE SURFACE OF THE DWARF PLANET. A NEW PIXEL-BY-PIXEL HAPKE RADIATIVE TRANSFER MODEL HAS BEEN DEVELOPED BY PI PROTOPAPA (PROTOPAPA ET AL. 2017). THIS HAPKE-BASED TECHNIQUE WAS APPLIED TO TWO NH RALPH/LEISA RESOLVED SCANS OF PLUTO S ENCOUNTER HEMISPHERE YIELDING COMPOSITIONAL MAPS DEFINING THE SPATIAL DISTRIBUTION OF THE ABUNDANCE AND TEXTURAL PROPERTIES OF THE MATERIALS PRESENT ON THE SURFACE OF THE DWARF PLANET. THIS HAS BEEN BY FAR THE MOST SUCCESSFUL APPROACH IN TERMS OF PROVIDING QUANTITATIVE INFORMATION ABOUT THE COMPOSITION OF PLUTO. UP TO NOW HOWEVER THIS IMPROVED PIXEL-BY-PIXEL HAPKE RADIATIVE TRANSFER MODEL HAS BEEN APPLIED TO ONLY TWO SCANS OF PLUTO OUT OF TEN WELL RESOLVED SCANS RECORDED BY THE NH S INFRARED IMAGING SPECTROMETER LEISA. NO QUANTITATIVE COMPOSITIONAL INFORMATION HAS BEEN DERIVED FROM NH S OBSERVATIONS OF THE NON-ENCOUNTER HEMISPHERE OF PLUTO. THUS OUR QUANTITATIVE UNDERSTANDING OF PLUTO S COMPOSITION TODAY IS MUCH MORE LIMITED THAN THE DATA ALLOW. FURTHERMORE IMPORTANT COMPOSITIONAL INFORMATION IS HIDDEN IN THE VISIBLE WAVELENGTH RANGE WHERE ORGANIC COMPOUNDS KNOWN AS THOLINS PRESENT THE MOST DIAGNOSTIC SPECTRAL SIGNATURES. HIGH QUALITY DATA IN THIS RANGE EXIST FROM THE NH RALPH/MVIC INSTRUMENT BUT HAVE YET NOT BEEN STUDIED WITH THIS TECHNIQUE. THE HIGH-SPATIAL-RESOLUTION NH DATA IS COMPLEMENTARY TO A LARGE QUANTITY OF VISIBLE AND NEAR-INFRARED GROUND-BASED MEASUREMENTS WHICH HAVE BEEN ACQUIRED OVER THE LAST DECADE TO MONITOR PLUTO OVER TIMESCALES OF YEARS. HOWEVER NO EFFORT HAS YET BEEN FUNDED TO EXAMINE QUANTITATIVELY IN A SYSTEMATIC WAY OVER A DECADE S-WORTH OF VISIBLE AND INFRARED GROUND-BASED SPECTRA OF THE PLUTO/CHARON SYSTEM. WE PROPOSE TO ANALYZE NH MVIC AND LEISA SPECTRAL SCANS OF PLUTO AND CHARON AS WELL AS GROUND-BASED VISIBLE AND NEAR-INFRARED SPECTROSCOPIC DATA OF THE SYSTEM USING A MODERN RADIATIVE TRANSFER CODE. THIS WAY WE WILL SYSTEMATICALLY AND QUANTITATIVELY INVESTIGATE THE SPATIAL DISTRIBUTION AND LONG-TERM EVOLUTION OF PLUTO S VOLATILE ICES WHILE IDENTIFYING THE PHYSICAL AND CHEMICAL PROCESSES THAT GOVERN THE INTERACTIONS BETWEEN PLUTO S SURFACE AND ITS ATMOSPHERE.