CLIMATE CHANGE ANALYSES USING THERMAL INFRARED SPECTRAL RADIANCES AND GEOPHYSICAL PRODUCT RETRIEVALSSPECTRALLY RESOLVED INFRARED MEASUREMENTS ARE PROVING TO BE OF GREAT BENEFIT FOR A WIDE RANGE OF CLIMATE STUDIES. HERE WE ARE FOCUSED ON THEIR APPLICATION TO CLIMATE BENCHMARKING AND DECADAL CLIMATE TREND ASSESSMENT THAT IS A KEY PART OF THE NASA CLIMATE ABSOLUTE RADIANCE AND REFRACTIVITY OBSERVATORY (CLARREO) MISSION NAMED A TIER 1 MISSION BY THE 2007 NRC DECADAL SURVEY. IN THIS CONTEXT WE PROPOSE TO SIGNIFICANTLY EXPAND ON TECHNIQUES DEVELOPED BY OUR GROUP AS PART OF THE CLARREO SCIENCE DEFINITION TEAM (SDT) BY ADVANCING THE DEFINITION OF CLIMATE PRODUCTS THAT CAN BE DERIVED FROM HIGH SPECTRAL RESOLUTION EARTH EMITTED RADIANCES BY DERIVING ASSOCIATED UNCERTAINTY ESTIMATES AND BY APPLYING THESE TECHNIQUES TO THE EVALUATION OF TRENDS FROM EXISTING DATA SETS AND CLIMATE MODELS. THEREFORE THE SPECIFIC OBJECTIVES OF THIS PROPOSAL ARE TO1. ASSESS THE UNCERTAINTY OF INFRARED SPECTRAL RADIANCES AND DERIVED GEOPHYSICAL PRODUCTS 2. INTERPRET OBSERVED SPECTRAL RADIANCE TRENDS VARIABILITY AND CORRELATION 3. EVALUATE A SINGLE-PIXEL CLIMATE TREND RETRIEVAL METHODOLOGY AND 4. QUANTIFY UNCERTAINTIES IN DERIVED PRODUCT TRENDS AND NATURAL VARIABILITY. WE EXPECT THE PROPOSED EFFORT TO MAKE A SIGNIFICANT CONTRIBUTION TO FUTURE GLOBAL CLIMATE OBSERVING SYSTEM FOCUSED ON REGIONAL ZONAL AND GLOBAL SCALES. A KEY ASPECT OF THIS EFFORT WILL BE PARALLEL INTERPRETATION OF LEVEL 3 PRODUCTS DERIVED (1) DIRECTLY FROM LEVEL 1 SPECTRAL RADIANCES AND (2) FROM LEVEL 2 RETRIEVALS OF GEOPHYSICAL PRODUCTS (STATE PARAMETERS TRACE GASES AND CLOUD PROPERTIES) AND ASSESSING THE ERRORCHARACTERISTICS OF EACH. THIS APPROACH WILL FACILITATE EVALUATION OF BIASES THAT MAY ARISE FROM THE RETRIEVAL PROCESS. ANOTHER KEY ASPECT WILL BE THE USE OF LEVEL 3 PRODUCTS CONSISTING OF PROBABILITY DISTRIBUTION FUNCTIONS (PDFS) AND HIGHER STATISTICAL MOMENTS IN ADDITION TO MEANS. THE INCORPORATION OF A RETRIEVAL APPROACH THAT CAN BE APPLIED TO EACH INDIVIDUAL OBSERVATION IS NEEDED FOR BEING ABLE TO ASSESS PDFS OF BOTH RADIANCES AND RETRIEVALS IN A CONSISTENT MANNER. THIS IS ESSENTIAL FOR PRESERVING THE FULL INFORMATION CONTENT OF CLIMATE PRODUCTS OVER LARGE SPATIAL AND TEMPORAL SCALES. TO ADVANCE THE FOUNDATION FOR CLARREO-TYPE MISSIONS WE WILL DEMONSTRATE THESE APPROACHES THROUGH APPLICATION TO THE EXISTING DECADAL HIGH RESOLUTION INFRARED RADIANCE RECORD [THE 11+ YEAR RECORD FROM THE NASA EOS AQUA AIRS SENSOR (SEPTEMBER 2002 - CURRENT) WHICH OVERLAPS THE OPERATIONAL METOP - A IASI SENSOR (2007 - PRESENT) THE METOP-B IASI SENSOR (2013 - PRESENT) AND THE NPP CRIS SENSOR (2012 - PRESENT)] AND TO CLIMATE MODEL DATA PRODUCED BY THE CLARREO SDT. THE ERROR ASSESSMENTS WILL BE MADE BOTH THROUGH DERIVING DETAILED ERROR BUDGETS AND THROUGH COMPARISON OF PRODUCTS WITH INDEPENDENT VALIDATION DATA. THE DUAL REGRESSION (DR) RETRIEVAL METHODOLOGY PROPOSED HERE IS EXCEPTIONALLY WELL SUITED TO APPLICATION TO LARGE CLIMATE DATA SETS OF BOTH OBSERVED SPECTRAL DATA AND SIMULATED SPECTRAL DATA FROM NUMERICAL WEATHER PREDICTION AND GLOBAL CLIMATE MODELS.BETTER QUANTIFICATION OF DECADAL CLIMATE TRENDS THROUGH COUPLING OUR BEST MEASUREMENTS AND OUR BEST MODELS WILL BE CRITICAL TO SETTING BETTER NATIONAL AND INTERNATIONAL CLIMATE AND ENERGY POLICIES.