WE PROPOSE TO UTILIZE ADVANCES IN SPECIFYING AND MODELING SOLAR IRRADIANCE VARIABILITY ACHIEVED BY THE SIST (2015-2018) TO CONSTRUCT A NEW GENERATION OF SOLAR IRRADIANCE VARIABILITY MODELS WITH ENHANCED COMMUNITY AND OPERATIONAL UTILITY. THESE MODELS ARE ESSENTIAL INPUTS TO EARTH SCIENCE RESEARCH AND BECAME OPERATIONAL IN 2015 WITHIN NOAAS CLIMATE DATA RECORD (CDR). WE PROPOSE THREE OVERARCHING IMPROVEMENTS OF THE MODELS: 1) INCORPORATING AN OPERATIONAL GOES-16 MG INDEX THEREBY INCREASING RELIABILITY AND REPEATABILITY 2) INCREASING SPECTRAL RESOLUTION FROM 1 NM TO 0.1 MM THEREBY FACILITATING IMPROVED ATMOSPHERIC RADIATIVE TRANSFER ALGORITHMS AND 3) USING DERIVATIVES OF TOTAL SOLAR IRRADIANCE OBSERVATIONS TO MODEL ACCOMPANYING SPECTRAL IRRADIANCE CHANGES THEREBY PROVIDING A POTENTIALLY SUPERIOR MODEL AND AN ALTERNATIVE CAPABILITY IN THE ADVENT OF MISSING PROXIES. 1) SOLAR IRRADIANCE VARIES IN RESPONSE TO TWO PRIMARY SOLAR FEATURES BRIGHT FACULAE AND DARK SUNSPOTS AND MODELS OF IRRADIANCE VARIABILITY REQUIRE PROXIES OF BOTH. NOAAS SOLAR IRRADIANCE CDR MODELS INPUT THE BREMEN MG FACULAR INDEX AND A SUNSPOT DARKENING INDEX CALCULATED FROM OBSERVATIONS OF THE SOLAR OBSERVING OPTICAL NETWORK (SOON). SOON IS A US AIR FORCE OPERATIONAL PROGRAM AND THE AVAILABILITY OF SUNSPOT DATA IS RELATIVELY MORE SECURE THAN THE MG INDEX WHICH IS A RESEARCH PRODUCT. NOAAS GOES 16 SPACECRAFT LAUNCHED IN NOVEMBER 2016 REMEDIES THIS WITH OPERATIONAL MONITORING OF THE MG INDEX. FOR THE DURATION OF THE SIST WE PROPOSE TO CROSS-CALIBRATE THE GOES-16 AND BREMEN MG INDICES EVALUATE SOLAR IRRADIANCE VARIATIONS CALCULATED WITH BOTH INDICES AND COMPARE BOTH MODELS WITH TOTAL AND SPECTRAL IRRADIANCE OBSERVATIONS FROM THE SORCE AND TSIS SPACECRAFT. BY THE END OF THE THREE-YEAR SIST EFFORT WE EXPECT TO UTILIZE THE GOES-16 MG INDEX TO GENERATE THE NOAA SOLAR IRRADIANCE CDR PLACING THIS CDR ON A FULLY OPERATIONAL FOUNDATION. 2) WHILE THE 1 NM SPECTRAL RESOLUTION OF EXTANT SPECTRAL IRRADIANCE VARIABILITY MODELS IS ADEQUATE FOR SOME TERRESTRIAL APPLICATIONS HIGHER RESOLUTION IS NECESSARY FOR FUNDAMENTAL LINE-BY-LINE RADIATIVE TRANSFER CALCULATIONS THAT UNDERLIE MULTIPLE PARAMETERIZATIONS IN THESE APPLICATIONS (INCLUDING IN GENERAL CIRCULATION MODELS). ATMOSPHERIC ENVIRONMENTAL RESEARCH (AER) HAS INCORPORATED THE NRLSSI2 1-NM MODEL OF SOLAR SPECTRAL IRRADIANCE VARIABILITY (THE NOAA CDR) TO THEIR LBLRTM CODE. WE PROPOSE TO DEVELOP MODELS WITH 0.1 NM RESOLUTION AT ULTRAVIOLET AND VISIBLE WAVELENGTHS BY ANALYZING HIGH RESOLUTION SPECTRA MEASURED BY SORCE SOLSTICE AND OMI. THE HIGHER SPECTRAL RESOLUTION MODEL WILL BE AVAILABLE TO AER FOR USE IN FUTURE LINE-BY-LINE CODES AND TRANSITIONED OPERATIONALLY TO THE NOAA CDR IN SUPPORT OF GSICS REQUIREMENTS FOR HIGHER SPECTRAL RESOLUTION REFERENCE SPECTRA. 3) THE LONG-TERM REPEATABILITY OF SPECTRAL IRRADIANCE VARIABILITY MODELS DEPENDS ON THE STABILITY OF FACULAR AND SUNSPOT PROXIES. THE LONG-TERM REPEATABILITY OF TOTAL SOLAR IRRADIANCE OBSERVATIONS MADE BY THE TOTAL SOLAR IRRADIANCE MONITOR (TIM) MAY BE SUPERIOR TO THAT OF EITHER OF THESE PROXIES. THEREFORE A MODEL OF SOLAR SPECTRAL IRRADIANCE VARIABILITY THAT INCORPORATES DIRECT OBSERVATIONS OF TOTAL SOLAR IRRADIANCE IN LIEU OF ONE OR OTHER OF THE PROXIES MAY PROVE SUPERIOR TO CURRENT MODELS. WE PROPOSE TO GENERATE NEW MODELS OF SOLAR SPECTRAL IRRADIANCE VARIABILITY USING THE TOTAL SOLAR IRRADIANCE OBSERVED BY TIM ON SORCE AND TSIS AND ONE OR OTHER PROXY INPUT (EITHER FACULAR BRIGHTENING OR SUNSPOT DARKENING). THE NEW MODELS OF SOLAR SPECTRAL IRRADIANCE WILL BE VALIDATED WITH THE TSIS SIM OBSERVATIONS THAT ARE IMPROVED IN TECHNOLOGICAL DESIGN FROM SORCE SIM TO ACHIEVE HIGHER ACCURACY AND GREATER LONG-TERM STABILITY. AS PART OF THIS NEW APPROACH WE WILL IMPROVE THE SOON SUNSPOT DARKENING FUNCTION USING OTHER DATABASES OF SUNSPOT AREAS AND LOCATIONS SUCH AS THAT OF THE DEBRECEN OBSERVATORY.