MODELING WAVE FORCING OF THE COUPLED ATMOSPHERE - IONOSPHERE SYSTEM EARTH S UPPER ATMOSPHERE AND IONOSPHERE COMPRISE A HIGHLY COUPLED SYSTEM THAT RESPONDS STRONGLY TO TERRESTRIAL FORCING FROM REGIONAL TO GLOBAL SCALES. TIDES AND PLANETARY WAVES (PWS) ACHIEVE LARGE AMPLITUDES AND EXHIBIT STRONG VARIABILITY IN THE MESOSPHERE LOWER THERMOSPHERE AND IONOSPHERE (MLTI). THESE MOTIONS DRIVE GLOBAL DYNAMO ELECTRIC FIELDS AND CURRENTS AND PRECONDITION THE IONOSPHERE FOR VARIOUS PLASMA INSTABILITIES. SMALLER-SCALE GRAVITY WAVES (GWS) PROPAGATING FROM SOURCES IN THE LOWER ATMOSPHERE OR EXCITED IN THE MLT BY SOLAR AND TERRESTRIAL FORCING ALSO PLAY KEY ROLES IN REGIONAL AND GLOBAL DYNAMICS. THEIR EFFECTS ARE EXPECTED TO INCLUDE STRONG REGIONAL VARIABILITY IN WINDS NEUTRAL AND PLASMA DENSITIES ACCOMPANYING FIELDS AND CURRENTS LARGE ENERGY AND MOMENTUM INPUTS INTO THE MLT AND SEEDING OF EPBS AND TIDS FROM EQUATORIAL TO HIGHER LATITUDES. IMPORTANTLY THERE ARE MAJOR DEFICIENCIES IN THE DESCRIPTIONS OF TIDAL STRUCTURES AND IONOSPHERIC EFFECTS IN THE MAJORITY OF GLOBAL MODELS AT PRESENT THAT LIMIT GLOBALSCALE MODELING AND PREDICTABILITY. THERE HAVE ALSO BEEN NO SYSTEMATIC STUDIES TO DATE OF THE PROPAGATION AND EFFECTS OF NONLINEAR GWS ON REGIONAL AND GLOBAL MLTI COUPLED DYNAMICS. FINALLY THERE HAVE BEEN NO ATTEMPTS TO INCLUDE SELF-CONSISTENT 3D ELECTRODYNAMICS IN A COUPLED GLOBAL MODEL PROVIDING SENSITIVITY TO THE FULL SPECTRUM OF TERRESTRIAL FORCING SCALES. ALL OF THESE COMPONENTS ARE CRITICAL TO ACHIEVING COMPREHENSIVE MODELING CAPABILITIES AND THEY COMPRISE OUR COLLECTIVE FOCI IN THE PROPOSED RESEARCH. GW TIDAL AND PW COUPLING IS A PHYSICAL PROCESS FUNDAMENTAL TO MOST PLANETARY ATMOSPHERES AND A KEY ELEMENT OF SOLAR-TERRESTRIAL COUPLING. THE PROPOSAL WILL SPECIFICALLY ADDRESS SCIENCE GOALS 2 AND 4 OF THE HELIOPHYSICS DECADAL SURVEY (SOLAR AND SPACE PHYSICS: A SCIENCE FOR A TECHNOLOGICAL SOCIETY) WHICH ARE: 2. DETERMINE THE DYNAMICS AND COUPLING OF EARTH S MAGNETOSPHERE IONOSPHERE AND ATMOSPHERE AND THEIR RESPONSE TO SOLAR AND TERRESTRIAL INPUTS; 4. DISCOVER AND CHARACTERIZE FUNDAMENTAL PROCESSES THAT OCCUR BOTH WITHIN THE HELIOSPHERE AND THROUGHOUT THE UNIVERSE. OUR APPROACH WILL INVOLVE APPLICATIONS OF GLOBAL AND REGIONAL MODELS EACH OF WHICH HAS UNIQUE CAPABILITIES NEEDED TO ACHIEVE OUR RESEARCH OBJECTIVES. THESE MODELS INCLUDE: 1) THE WACCM GCM (0-200 KM) FOR DEEP NEUTRAL DYNAMICS GCM TRUE METEOROLOGICAL FORCING REALISTIC TIDES AND PWS AND BOUNDARY CONDITIONS FOR DEEP (0-500 KM) REGIONAL HIGH-RESOLUTION (~200 M) MODELING USING A COMPRESSIBLE FINITE-VOLUME (CFV) CODE 2) A 3D CFV CODE ADDRESSING NONLINEAR GW DYNAMICS USING A STRETCHED GRID ENABLING FULL RESOLUTION OF GW DYNAMICS AT SMALL SCALES IN LARGE REGIONAL (3000X3000 KM) DOMAINS 3) THE COUPLED SAMI3 AND SAMI3/ESF IONOSPHERIC MODEL WILL BE USED TO CAPTURE 3D ELECTRODYNAMICS USING WACCM INPUT AND HIGH RESOLUTION GW DYNAMICS USING CFV INPUTS. THESE CAPABILITIES WILL ENABLE OUR TEAM TO EXPLORE 1) INFLUENCES OF REALISTIC TERRESTRIAL FORCING TIDAL FIELDS MLTI WINDS AND NEUTRAL-ION CHEMISTRY FOR THE COUPLED MLTI SYSTEM 2) REGIONAL AND GLOBAL INFLUENCES OF NONLINEAR GWS PENETRATING INTO THE MLTI AND 3) PLASMA RESPONSES TO THESE NEUTRAL DRIVERS FROM LOCAL TO GLOBAL SCALES. OUR TEAM WILL INCLUDE DAVE FRITTS BRIAN LAUGHMAN AND A GRAD STUDENT AT GATS HAN-LI LIU AND JOE MCINERNEY AT NCAR JOE HUBA AND JOHN KRALL AT NRL AND TOM LUND AT NWRA. DAVE WILL COORDINATE THE OVERALL TEAM EFFORT AND GW MODELING BY BRIAN TOM AND THE GRAD STUDENT. HAN-LI WILL EMPLOY WACCM TO DESCRIBE THE LARGE-SCALE ENVIRONMENT AND PROVIDE BOUNDARY CONDITIONS FOR CFV CODE GW STUDIES BY GATS AND NWRA PERSONNEL. JOE HUBA AND JOHN KRALL AT NRL WILL EMPLOY THE SAMI3 AND SAMI3/ESF CODE FOR VERYHIGH- RESOLUTION STUDIES EMPLOYING THE WACCM AND CFV INPUT FIELDS TO SIMULTANEOUSLY ADDRESS SMALL-SCALE RESPONSES TO GWS IN THE CONTEXT OF THE LARGER-SCALE TIDAL AND PW INFLUENCES.