THE DYNAMICS AND CHEMISTRY OF THE SUMMER STRATOSPHERE (DCOTSS) IS A FIVE-YEAR PROJECT AIMING TO ADVANCE UNDERSTANDING OF CHANGES IN THE EARTH S RADIATION BALANCE AIR QUALITY AND THE OZONE LAYER THAT RESULT FROM CHANGES IN ATMOSPHERIC COMPOSITION AND WILL IMPROVE THE CAPABILITY TO PREDICT WEATHER AND EXTREME WEATHER EVENTS. DCOTSS WAS COMPETITIVELY SELECTED FOR FUNDING IN RESPONSE TO ROSES 2017 SOLICITATION NNH17ZDA001N UNDER NASA S EARTH VENTURE SUBORBITAL-3 PROGRAM. THE NORTH AMERICAN MONSOON ANTICYCLONE (NAMA) DOMINATES THE CIRCULATION OF THE NORTH-WESTERN HEMISPHERE AND ACTS TO PARTIALLY CONFINE AND ISOLATE AIR FROM THE SURROUNDING ATMOSPHERE. STRONG CONVECTIVE STORMS IN THE NAMA REGULARLY PENETRATE DEEP INTO THE LOWER STRATOSPHERE LS. THE UNIQUENESS OF THE NAMA REGION IS MOST EASILY SEEN IN SATELLITE MEASUREMENTS OF WATER VAPOR WHICH SHOW A LARGE ENHANCEMENT IN THE LS OVER NORTH AMERICA NOT SEEN EITHER IN MAGNITUDE OR AT SUCH HIGH LATITUDES ELSEWHERE AROUND THE GLOBE. BUT THE COUPLING OF TROPOPAUSE-PENETRATING CONVECTION WITH LARGE-SCALE MONSOONAL MOTION IS POORLY UNDERSTOOD AS IS THE IMPACT OF CONVECTION ON THE CHEMICAL COMPOSITION OF THE LS BOTH IN MONSOON REGIONS AND IN THE GLOBAL STRATOSPHERE WHICH RECEIVES INPUTS OF MOIST AND POLLUTED MONSOON AIR FROM THE NAMA. THE DCOTSS DIRECTLY ADDRESSES THIS KNOWLEDGE GAP WITHIN THREE MAIN FOCUS AREAS. DCOTSS WILL DEPLOY THE NASA ER-2 TO SALINA KS AND EMPLOY A SUITE OF 12 IN-SITU INSTRUMENTS MEASURING GASES (AWAS CAF HUPCRS HOZ HWV UCATS WI- ICOS) AEROSOLS (PALMS POPS) REACTIVE SPECIES (HAL CANOE) AND METEOROLOGICAL PARAMETERS (MMS.) THE NASA ER-2 IS THE IDEAL AIRCRAFT FOR DCOTSS. IT OFFERS AMPLE PAYLOAD BOTH IN TERMS OF VOLUME AND WEIGHT AS WELL AS THE CAPABILITY OF REACHING ALTITUDES OF ~21 KM. DCOTSS CONSISTS OF A 5-WEEK TEST FLIGHT SERIES OUT OF PALMDALE CA AND THREE 8-WEEK SCIENCE DEPLOYMENTS OUT OF SALINA KS DURING SPRING MIDDLE SUMMER AND LATE SUMMER. THIS PROPOSAL SETS OUT THE WORK AND BUDGET FOR THE BAER INSTITUTE PERSONNEL IN SUPPORTING THE DCOTSS MISSION. PERSONNEL FROM BAER INSTITUTE WILL PLAY INTEGRAL ROLES IN THE FIELD DEPLOYMENT MANAGEMENT (FDM) TEAM FROM NASA AMES RESEARCH CENTER S EARTH SCIENCE PROJECT OFFICE (ESPO). THE FDM TEAM WILL WORK WITH THE LEAD PRINCIPAL INVESTIGATOR FROM TEXAS A&M TO MANAGE THE INVESTIGATION IMPLEMENT THE FIELD DEPLOYMENTS AND COORDINATE RELEVANT ASPECTS OF PROGRAMMATIC REPORTING AT INVESTIGATION STATUS REVIEWS.