THIS PROPOSAL SEEKS FIVE YEARS OF CONTINUING FUNDING FOR THE MULTINATIONAL GLOBAL ATMOSPHERIC MEASUREMENT PROGRAM ENTITLED ADVANCED GLOBAL ATMOSPHERIC GASES EXPERIMENT (AGAGE). THE CASE FOR REAL-TIME HIGH-FREQUENCY MEASUREMENT NETWORKS IS VERY STRONG AND THE OBSERVATIONS AND THEIR INTERPRETATION ARE RECOGNIZED WIDELY FOR THEIR IMPORTANCE TO OZONE DEPLETION AND CLIMATE CHANGE STUDIES AND TO VERIFICATION ISSUES ARISING FROM THE MONTREAL (OZONE) AND KYOTO AND SUCCESSOR (CLIMATE) PROTOCOLS.AGAGE IS DISTINGUISHED BY ITS CAPABILITY TO MEASURE GLOBALLY AT HIGH FREQUENCY ALL THE IMPORTANT SPECIES IN THE MONTREAL PROTOCOL AND ALL THE IMPORTANT NON-CO2 GASES IN THE KYOTO PROTOCOL. THE SCIENTIFIC OBJECTIVES OF AGAGE ARE IMPORTANT IN FURTHERING UNDERSTANDING OF GLOBAL CHEMICAL AND CLIMATIC PHENOMENA. THEY ARE:1) DETERMINE OPTIMALLY FROM OBSERVATIONS THE GLOBAL RATES OF EMISSION AND/OR DESTRUCTION (I.E. LIFETIME) OF ANTHROPOGENIC CHLOROCARBONS CHLOROFLUOROCARBONS (CFCS) BROMOCARBONS HYDROCHLOROFLUOROCARBONS (HCFCS) HYDROFLUOROCARBONS (HFCS) AND PERFLUORINATED COMPOUNDS (PFCS NF3 AND SF6) THAT CONTRIBUTE MOST OF THE REACTIVE HALOGEN TO THE STRATOSPHERE AND/OR ARE STRONG INFRARED ABSORBERS.(2) DOCUMENT ACCURATELY THE GLOBAL DISTRIBUTIONS AND TEMPORAL BEHAVIORS OF BIOGENIC/ANTHROPOGENIC GASES IMPORTANT IN CLIMATE CHANGE AND/OR OZONE DEPLETION: METHANE NITROUS OXIDE CARBON MONOXIDE HYDROGEN METHYL CHLORIDE AND METHYL BROMIDE.(3) IDENTIFY GREENHOUSE AND OZONE-DEPLETING GASES (E.G. SO2F2 NF3 C4F10 C5F12 C6F14 C7F16 AND C8F18 HAVE BEEN IDENTIFIED) INITIATE REAL-TIME MONITORING OF THESE GASES AND RECONSTRUCT THEIR PAST HISTORIES FROM AGAGE AND AIR-ARCHIVE MEASUREMENTS.(4) DETERMINE OPTIMALLY THE AVERAGE CONCENTRATIONS AND TRENDS OF TROPOSPHERIC HYDROXYL RADICALS FROM THE RATES OF DESTRUCTION OF ATMOSPHERIC METHYL CHLOROFORM HFCS AND HCFCS AND ESTIMATES OF THEIR EMISSIONS.(5) DETERMINE OPTIMALLY FROM ATMOSPHERIC OBSERVATIONS AND ESTIMATES OF THEIR DESTRUCTION RATES THE MAGNITUDES AND DISTRIBUTIONS BY REGION OF SURFACE SOURCES/SINKS OF THESE GASES.(6) PROVIDE ACCURATE DATA ON THE GLOBAL ACCUMULATION OF THESE TRACE GASES WHICH ARE USED TO TEST THE SYNOPTIC/REGIONAL/GLOBAL-SCALE CIRCULATIONS PREDICTED BY THREE-DIMENSIONAL MODELS.(7) PROVIDE GLOBAL AND REGIONAL MEASUREMENTS OF METHANE CARBON MONOXIDE AND HYDROGEN AND ESTIMATES OF HYDROXYL LEVELS TO TEST PRIMARY ATMOSPHERIC OXIDATION PATHWAYS AT MID-LATITUDES AND THE TROPICS.