FOR THE PERIOD OF PERFORMANCE THE PI WILL CONTINUE HER CLOSE COLLABORATION WITH THE SABER SCIENCE TEAM. THIS INVOLVES RESEARCH ORIGINATED BY SMITH AS WELL AS CONTRIBUTIONS TO AND COLLABORATIONS ON STUDIES FROM SABER TEAM MEMBERS AND FROM OTHERS IN THE COMMUNITY. SHE CURRENTLY HAS ACTIVE COLLABORATIONS WITH SABER TEAM MEMBERS M. LOPEZ PUERTAS P. ESPY M. MLYNCZAK AND R. GARCIA. SHE WILL CONTINUE TO ATTEND AND PARTICIPATE IN THE SABER SCIENCE TEAM MEETINGS AND TELECONS AND TO EVALUATE NEW OR PROPOSED RETRIEVALS AND DATA PRODUCTS. PARTICULAR RESEARCH TOPICS ARE: I. IN COLLABORATION WITH OTHER SABER TEAM MEMBERS INVESTIGATE THE COMPATIBILITY OF OXYGEN AND HYDROGEN SPECIES IN THE MESOSPHERE. THIS IS MOTIVATED BY THE NEW RETRIEVALS OF NIGHTTIME O AND H (PERSONAL COMMUNICATION FROM M. MLYNCZAK AND L. HUNT; NOT YET RELEASED TO THE PUBLIC) THAT SHOW CONCENTRATIONS OF BOTH THAT ARE LOWER THAN IN V2.0. BASED ON THE CURRENT UNDERSTANDING OF CHEMISTRY 0 AND 0 3 SHOULD BE IN PHOTOCHEMICAL EQUILIBRIUM DURING BOTH DAY AND NIGHT. FURTHERMORE THERE SHOULD BE CONSISTENCY BETWEEN THE DAY AND NIGHT VALUES. THESE WERE GENERALLY CONSISTENT IN V2.0 WHICH SUGGESTS THAT THE NEW LOWER NIGHTTIME O WILL BE INCONSISTENT WITHOUT ADJUSTMENTS IN THE RETRIEVALS OF DAY AND NIGHT 0 3 AND DAY 0. HOWEVER SUCH ADJUSTMENTS CAN ONLY BE MADE AFTER CAREFUL CONSIDERATION OF THE LABORATORY CONSTRAINTS ON PARAMETERS THAT AFFECT THE RETRIEVALS. 2. SMITH ET AL. (2017) SHOWED THAT THE SAO WINDS IN THE MIDDLE ATMOSPHERE HAVE A HIGH DEGREE OF INTERANNUAL VARIABILITY. PART OF THAT VARIABILITY IS DUE TO INTERACTIONS WITH THE QBO ALTHOUGH THE NATURE OF THAT INTERACTION IS NOT KNOWN. OTHER CONTRIBUTIONS TO THE VARIABILITY ARE NOT KNOWN BUT LIKELY INCLUDE EXTRA-TROPICAL DYNAMICAL ACTIVITY PARTICULARLY DURING NORTHERN HEMISPHERE WINTER AND VARIATIONS IN THE GENERATION OF TROPICAL WAVES ASSOCIATED WITH ENSO OR INTRA-SEASONAL OSCILLATION IN THE TROPICAL TROPOSPHERE. THIS TOPIC WILL BE INVESTIGATED USING SABER DATA OTHER SATELLITE OR REANALYSIS DATA AND W ACCM. 3. RETRIEVALS OF TEMPERATURE FROM OH MEINEL EMISSIONS HAVE BEEN USED IN GROUND-BASED INVESTIGATIONS OF THE MESOSPHERE. BECAUSE OF THE LONG RECORDS FROM SOME SITES THESE OBSERVATIONS HAVE BEEN APPLIED FOR DEDUCING TRENDS RESPONSE TO THE SOLAR CYCLE .AND OTHER DYNAMICAL PROCESSES. SABER OBSERVATIONS SHOW THAT THE ALTITUDE REGION FROM :WHICH THESE EMISSIONS ORIGINATE IS NOT STEADY BUT MOVES QUITE EXTENSIVELY (MORE THAN A FEW KM) DEPENDING ON CONDITIONS. SINCE TEMPERATURE ALSO VARIES WITH ALTITUDE THIS DISPLACEMENT IN ALTITUDE CAN HAVE AN IMPORTANT IMPACT ON THE DEDUCED TRENDS. TO INVESTIGATE THE IMPACT OF THIS THE PI WILL INITIATE COLLABORATION WITH SCIENTISTS OPERATING ONE OR MORE OF THE GROUNDBASED FACILITIES.