A BETTER UNDERSTANDING OF THE VARIABILITY OF THE IONOSPHERE IS IMPORTANT FOR SPACE WEATHER PREDICTION. PREVIOUS STUDIES HAVE SHOWN SIGNIFICANT VARIATIONS IN THE IONOSPHERE AND THEIR CONNECTIONS TO LOWER ATMOSPHERIC FORCING INCLUDING ATMOSPHERIC TIDES PLANETARY WAVES AND GRAVITY WAVES (GWS). ATMOSPHERIC GWS ARE KNOWN TO HAVE SIGNIFICANT INFLUENCES IN THE MESOSPHERE THE THERMOSPHERE AND THE IONOSPHERE HOWEVER A SYSTEMATIC STUDY OF GW INFLUENCES ON THE VARIABILITY OF THE UPPER ATMOSPHERE HAS NOT BEEN FULLY CONDUCTED IN-PART OWING TO THE CHALLENGES IN OBSERVING GWS ON A GLOBAL SCALE AND COLLECTING A LONG-TERM GW DATASET. HIGH-RESOLUTION WHOLE ATMOSPHERIC MODELS CAN RESOLVE GWS HOWEVER THEIR SIMULATIONS ARE STILL LIMITED TO SHORT-TERM SIMULATIONS BECAUSE OF THE REQUIRED COMPUTATIONAL EXPENSE. OTHER GLOBAL GENERAL CIRCULATION MODELS USE PARAMETRIZATIONS OF GWS TO SIMULATE THEIR INFLUENCE BUT THESE PARAMETRIZATIONS ARE KNOWN TO HAVE SHORT-COMINGS ESPECIALLY RELATED TO IMPORTANT NON-VERTICAL PROPAGATION OF GWS AND GW SOURCE DISTRIBUTIONS. THEREFORE IT IS CRITICAL TO CHARACTERIZE GLOBAL GWS USING LONG-TERM DATASET AND UNDERSTAND THEIR RESPONSE TO CLIMATE CHANGE SOLAR CYCLES INTRA-SEASONAL AND SHORT-TERM VARIATIONS TO BETTER UNDERSTAND THE COUPLING FROM THE LOWER ATMOSPHERE TO THE IONOSPHERE AND THE THERMOSPHERE AND ALSO TO IMPROVE GW PARAMETERIZATIONS. IN THIS STUDY 71 YEARS OF OUTPUT FROM A GW-RESOLVING ATMOSPHERE MODEL WILL BE USED THAT IS ABLE TO CHARACTERIZE GWS ON A GLOBAL-SCALE AND PROVIDE LONG-TERM CHARACTERISTICS OF THESE WAVES IN THE STRATOSPHERE. BUILDING ON RECENT WORK TO IDENTIFY GWS IN REMOTE-SENSING OBSERVATIONS VALIDATION WILL BE PERFORMED WITH SATELLITE OBSERVATIONS. THIS WORK AIMS TO (1) CHARACTERIZE GLOBAL GWS (AMPLITUDES FREQUENCY WAVELENGTHS AND MOMENTUM FLUXES) UP TO THE LOWER MESOSPHERE (2) UNDERSTAND INFLUENCES OF SOLAR CYCLE AND CLIMATE CHANGE ON GWS AND (3) QUANTIFY THE QUASI-BIENNIAL OSCILLATION (QBO) INTRA-SEASONAL VARIATIONS AND SHORT-TERM VARIATIONS OF GWS AND THEIR RESPONSE TO SOLAR CYCLE AND CLIMATE CHANGE. BY COMBINING ALL THESE FINDINGS THIS WORK WILL GIVE NEW INSIGHT INTO LONG-TERM TRENDS AND SOLAR CYCLE INFLUENCES ON GW VARIATIONS THAT COULD NOT BE SIMULATED OR OBSERVED BEFORE AND WILL CONTRIBUTE TO ADVANCING GW PARAMETRIZATION SCHEMES AND ALSO TO THE STUDY THE TERRESTRIAL-UPPER ATMOSPHERE COUPLING THROUGH GWS.