WE PROPOSE A FOCUSED STUDY OF HIGH-RESOLUTION GODDARD EARTH OBSERVING SYSTEM (GEOS) MODELING VALIDATION AND ANALYSIS TO INVESTIGATE ATMOSPHERIC WAVES AND THEIR INFLUENCES ON WINDS IN THE UPPER TROPOSPHERE AND STRATOSPHERE. WINDS AT THESE LEVELS GUIDE ROSSBY WAVE PROPAGATION AND TELECONNECTION PATTERNS THAT STRONGLY INFLUENCE THE SIMULATION OF REGIONAL-SCALE CLIMATE PATTERNS AND SKILL OF LONG-RANGE WEATHER FORECASTS. MOST CLIMATE AND WEATHER FORECASTING CENTERS HAVE RAISED THEIR MODEL LIDS IN RECOGNITION OF THE IMPORTANCE OF THESE UPPER LEVEL WINDS AND THE IMPORTANCE OF SIMULATING THE PROCESSES THAT CONTROL THEM. AT SEASONAL FORECAST MODEL RESOLUTIONS SMALL-SCALE WAVES REMAIN SEVERELY UNDER-RESOLVED YET THE INFLUENCE OF THEIR DRAG FORCES ON THE CIRCULATION IN THE UPPER TROPOSPHERE AND STRATOSPHERE MAKE THEM A KEY PLAYER IN PREDICTABILITY. GRAVITY WAVE DRAG PARAMETERIZATIONS THAT TREAT OROGRAPHIC AND NON-OROGRAPHIC WAVES ARE USED TO TUNE BOTH CLIMATE AND FORECAST MODELS WITH DEMONSTRATED EFFECTS ON BIAS REDUCTION AND FORECAST SKILL. THIS PROJECT WILL INFORM IMPROVED METHODS FOR SIMULATING SMALL-SCALE WAVE EFFECTS ON TWO IMPORTANT FEATURES OF THE CIRCULATION WITH DEMONSTRATED INFLUENCE ON SEASONAL PREDICTABILITY: THE TROPICAL LOWER STRATOSPHERE AND THE WINTER SEASON STRATOSPHERIC VORTEX. THIS PUTS OUR FOCUS ON OROGRAPHIC GRAVITY WAVES AND THOSE GENERATED BY LOCALIZED INTENSE RAIN EVENTS. THE NASA GLOBAL MODELING AND ASSIMILATION OFFICE S (GMAO S) GEOS-5 MODEL IS DESIGNED FOR SIMULATION AT A WIDE RANGE OF ATMOSPHERIC RESOLUTIONS: FOR EXAMPLE IT IS CURRENTLY CONFIGURED FOR CLIMATE SIMULATIONS WITH ~100 KM RESOLUTION AND SPECIALIZED HINDCASTING EXPERIMENTS ARE ROUTINELY RUN IN THE GRAY ZONE (FOR BOTH DEEP CONVECTION AND GRAVITY WAVES) AT ~6 KM. VERTICAL RESOLUTION IS CURRENTLY 72 LEVELS WITH EFFORTS TO DOUBLE THAT UNDERWAY. ATMOSPHERIC WAVES AND THEIR INTERACTION WITH GLOBAL AND REGIONAL CIRCULATION ARE QUITE SENSITIVE TO THESE RESOLUTION CHOICES BUT ALSO SENSITIVE TO MOIST PROCESSES SURFACE DRAG DIVERGENCE DAMPING AND OTHER DISSIPATION MECHANISMS. AS A RESULT RESOLUTION ALONE DICTATES NEITHER THE SCALES OF THE WAVES THAT CAN BE RESOLVED NOR OTHER WAVE PROPERTIES INCLUDING THEIR SOURCES GEOGRAPHIC DISTRIBUTIONS AND DRAG ON THE CIRCULATION. FOR EXAMPLE PREVIOUS HIGHRESOLUTION EXPERIMENTS LIKE THE 7-KM RESOLUTION NATURE RUN NEEDED STRONG PARAMETERIZED GRAVITY WAVES TO COUNTERACT THE EFFECTS OF EXPLICIT PLUS IMPLICIT DISSIPATION ON WAVES RESOLVED IN THE MODEL. THE PROJECT APPROACH INCLUDES (I) OBSERVATIONAL VALIDATION OF GRAVITY WAVES AND SMALL-SCALE HEAVY PRECIPITATION EVENTS IN EXISTING AND FUTURE HIGH-RESOLUTION SIMULATIONS WITH DIFFERENT DISSIPATION SETTINGS (II) EXPLORATORY LIMITED-AREA HIGH-RESOLUTION GEOS EXPERIMENTS TO PROBE EFFECTS OF DIFFERENT PHYSICS DISSIPATION AND RESOLUTION SETTINGS ON SMALL-SCALE RESOLVED GRAVITY WAVES AND LATENT HEATING SOURCES (III) AN UPDATE TO THE EXISTING OROGRAPHIC GRAVITY WAVE DRAG PARAMETERIZATION TO INCLUDE EFFECTS OF ANISOTROPY AND LOW-LEVEL WAVE TRAPPING AND (IV) ANALYSIS OF VALIDATED GLOBAL MODEL EXPERIMENTS TO INFER THE ROLES OF SMALL-SCALE WAVES ON MAJOR MODES OF VARIABILITY AND ON WIND BIASES. THE WORK IS EXPECTED TO RESULT IN A DRAMATIC IMPROVEMENT IN UNDERSTANDING OF THE PRECISE ROLES OF SMALL-SCALE WAVES ON CIRCULATION AND WILL ALSO INFORM THE GMAO S PLANNED FY 2019 TESTS OF A NEW PROTOTYPE GEOS MODEL THROUGH UNDERSTANDING OF A VARIETY OF MODEL SETTING CHOICES ON SMALL-SCALE WAVES AND GRID-SCALE PRECIPITATION.