NASA S FIRE IMPACTS ON REGIONAL EMISSIONS AND CHEMISTRY (FIRECHEM) IS PART OF AN INTERAGENCY COLLABORATION FOCUSED ON CHARACTERIZING THE EMISSIONS CHEMISTRY AND IMPACTS OF NORTH AMERICAN FIRES. THIS COLLABORATION INCLUDES NOAA S FIRE INFLUENCE ON REGIONAL AND GLOBAL ENVIRONMENTS EXPERIMENT (FIREX) THE JOINT FIRE SCIENCE PROGRAM S FIRE AND SMOKE MODEL EVALUATION EXPERIMENT (FASMEE) AND NSF S WESTERN WILDFIRE EXPERIMENT FOR CLOUD CHEMISTRY AEROSOL ABSORPTION AND NITROGEN (WE-CAN). NASA S CONTRIBUTION TO THIS COLLABORATION WILL BE TO CONDUCT AIRBORNE SAMPLING OF VARIOUS TYPES OF FIRES USING THE DC-8. AS OUTLINED IN THE FIRECHEM WHITE PAPER (HTTPS://ESPO.NASA.GOV/FIRECHEM_WHITE_PAPER) THIS CAMPAIGN HAS THREE MAJOR OBJECTIVES: 1. SAMPLING OF WILDFIRES IN COORDINATION WITH INTERAGENCY PARTNERS TO COMBINE NEAR AND FAR-FIELD OBSERVATIONS TO UNDERSTAND CHEMICAL EVOLUTION AND TRANSPORT AND EVALUATE DOWNWIND IMPACTS. 2. SAMPLING OF SMALL FIRES TO BUILD STATISTICS ON EMISSION FACTORS AND FUELS PLUME RISE SATELLITE DETECTABILITY AND INTEGRATED IMPACTS. 3. SAMPLING OF PRESCRIBED BURNS IN COORDINATION WITH FASMEE. WE PROPOSE TO FLY THE NCAR 4-CHANNEL CHEMILUMINESCENCE INSTRUMENT ON THE NASA DC-8 FOR THE IN-SITU MEASUREMENT OF NO NO2 NOY AND O3. THIS IS A WELL-PROVEN INSTRUMENT THAT HAS FLOWN IN MANY PROJECTS AND ON SEVERAL DIFFERENT PLATFORMS. FOR FIRECHEM THERE WILL BE AN EMPHASIS ON FAST-RESPONSE MEASUREMENTS SO SOME MINOR MODIFICATIONS WILL BE REQUIRED TO OPTIMIZE INSTRUMENT PERFORMANCE IN THIS RESPECT. ADDITIONALLY THE DECREASING AVAILABILITY AND EASE OF SHIPPING OF TOXIC GASES REQUIRED IN OUR MEASUREMENT OF O3 AND NOY WILL NECESSITATE SOME HARDWARE MODIFICATIONS. ONCE THE NECESSARY CHANGES ARE MADE THE INSTRUMENT WILL BE TESTED AND CALIBRATED IN THE LAB PRIOR TO INSTALLATION ON THE AIRCRAFT. WE WILL PROVIDE QUICK-LOOK DATA SHORTLY AFTER A FLIGHT TO ENABLE AN INITIAL ASSESSMENT OF OBSERVATIONS IN THAT FLIGHT AS WELL AS TO AID IN THE PLANNING OF SUBSEQUENT FLIGHTS. IN THE YEARS FOLLOWING THE MEASUREMENT CAMPAIGN WE WILL WORK CLOSELY WITH OTHER INVESTIGATORS ON THE INTEGRATED DATASET SO THAT WE CAN TACKLE FIRECHEM OBJECTIVES IN A COORDINATED FASHION. THE MEASUREMENTS PROPOSED HERE ARE CRITICAL TO THE AIRBORNE COMPONENT OF THE CAMPAIGN AS THEY ARE ESSENTIAL TO ADDRESSING MOST OF THE SCIENCE QUESTIONS DETAILED IN THE WHITE PAPER. NITROGEN OXIDES ARE EMITTED FROM FIRES IN VARIOUS AMOUNTS AND PLAY A MAJOR ROLE IN THE SUBSEQUENT CHEMICAL EVOLUTION OF FIRE-IMPACTED AIR INCLUDING BEING A CONTROLLING FACTOR IN THE AMOUNT OF OZONE PRODUCED. SCIENCE QUESTION 1 IS DIRECTED AT DETERMINING EMISSION FACTORS FOR GASES AND NOX (NO + NO2) WILL BE AMONG THE SPECIES OF INTEREST. IT WILL BE IMPORTANT TO DETERMINE HOW THE EMISSIONS OF THESE AND OTHER SPECIES VARY WITH FUEL AND FIRE CONDITIONS. SCIENCE QUESTION 2 IS AIMED AT UNDERSTANDING THE CHEMICAL EVOLUTION OF WILDFIRE EMISSIONS; THE NO NO2 AND O3 MEASUREMENTS ARE CRITICAL TO THIS. SCIENCE QUESTION 3 CONCERNS THE IMPACT OF FIRES ON LOCAL AIR QUALITY AND HOW MODELS ARE ABLE TO CAPTURE SUCH IMPACTS. THE PRODUCTION OF O3 GOVERNED BY WILDFIRE NOX EMISSIONS IS AN IMPORTANT ASPECT OF THIS. SCIENCE QUESTION 6 INVOLVES SATELLITES AND HOW WELL THEY CAN HELP IN ADDRESSING ALL THE OTHER QUESTIONS. THE MEASUREMENTS OF NO2 AND O3 ARE IMPORTANT TO THIS EFFORT AS THESE TWO SPECIES ARE AMONG THE FEW BOUNDARY LAYER SPECIES THAT ARE MEASURED BY SATELLITES. IN SUMMARY OUR SPECIFIC OBJECTIVES ARE TO MAKE IN SITU MEASUREMENTS OF O3 NO NO2 AND NOY FROM THE DC-8. THESE MEASUREMENTS ARE CRITICAL TO MANY OF THE SCIENTIFIC OBJECTIVES OF FIRECHEM AND THIS IS REFLECTED IN THE STATUS OF NO NO2 AND O3 BEING PRIORITY ONE MEASUREMENTS.