IGF::OT::IGF NASA RESEARCH ANNOUNCEMENT AWARD UNDER NRA NNH16ZDA001N-WEATHER MULTISCALE INVESTIGATIONS AND ANALYSIS OF TROPICAL CONVECTIVE PROCESSES DURING CPEX USING DAWN AND NUMERICAL MODELS. UNDER THIS CONTRACT, THE CONTRACTOR WILL DESIGN AIRBORNE DOPPLER WIND LIDAR MISSIONS TO STUDY THE CONVECTIVE PROCESSES, THEIR INTERACTIONS ON DIFFERING SCALES AND AT DIFFERING TIMES WITHIN THEIR LIFE CYCLE (INITIATION, GROWTH, ORGANIZATION AND DISRUPTION) IN THE TROPICS ON HORIZONTAL SCALES RANGING FROM THE CLOUD SCALE, THROUGH THE MESO AND SCALE AND ON TIME SCALES OF SECONDS TO SEVERAL DAYS, INCLUDING NIGHTTIME. MEASUREMENTS WILL BE TAKEN UNDER A VARIETY OF CONVECTIVE CONDITIONS, INCLUDING: 1) SUPPRESSED CONDITIONS WITH LITTLE CONVECTION AND ONLY ISOLATED TRADE WIND CU 2) ORGANIZED TRADE WIND CU WITH SOME PENETRATING CU 3) TOWERING CU-CB 4) ORGANIZED MESO-SCALE TO SYNOPTIC SCALE THE CONTRACTOR WILL INVESTIGATE THE PBL STRUCTURE, AEROSOLS AND CIRCULATIONS WITHIN THE LOWER TROPICAL TROPOSPHERE UNDER ALL CONDITIONS, INCLUDING THE PRESENCE OF THE SAL OR SYNOPTIC SCALE DISTURBANCES. A SPECIAL FOCUS WILL BE ON STUDYING THE EXISTENCE OF BOUNDARY LAYER ROLLS AND THE DISPARITY OF PBL DEPTH AS DEFINED BY MIXING, WIND PROFILE, AEROSOL CONCENTRATIONS OR MOISTURE/DENSITY. COMPARISONS WITH SATELLITE DERIVED PBL HEIGHTS WILL BE MADE WHEN POSSIBLE WITH REGARDS TO ORBIT AND CLOUDS. THE EFFORT WILL INCLUDE SEVERAL NUMERICAL MODELS AND DATA ASSIMILATION TECHNIQUES TO IDENTIFY THE BETTER DATA ASSIMILATION METHOD FOR DAWN WIND PROFILE DATA ASSIMILATION. THE COMMUNITY MESOSCALE WILL BE USED FOR WEATHER RESEARCH AND FORECASTING, THE NCEP OPERATIONAL HURRICANE MODEL AND THE NCEP GRIDPOINT STATISTICAL INTERPOLATION-BASED HYBRID ENSEMBLE VARIATIONAL TO INVESTIGATE THE IMPACT OF ASSIMILATING THE DETAILED WIND PROFILES FROM DAWN (AND OTHER CPEX MEASUREMENTS) ON NUMERICAL SIMULATIONS. THIS WILL INCLUDE THE IMPACT ON OVERALL FORECAST, IMPROVED REPRESENTATION OF LOW TO MID-LEVEL WIND FIELDS, THE ACCURACY OF CONVECTIVE INITIATION, EVOLUTION AND DISSIPATION FORECAST, THE ROLE OF VERTICAL SHEAR ON CONVECTIVE EVOLUTION AND THE INFLUENCE OF THE SAL. DAWN FLIGHTS WILL BE SIMULATED FOR POST LAUNCH ADM CAL/VAL BY INVESTIGATING HOW ESA'S ATMOSPHERIC DYNAMICS MISSION WIND LIDAR WILL PERFORM IN THE TROPICS, PARTICULARLY DURING CLOUDY OR NON-CLOUDY CONDITIONS. A SPECIAL FOCUS WILL BE PLACE UPON DAWN PERFORMANCE IN THE PRESENCE OF HIGH CIRRUS CLOUDS DURING HIGH ALTITUDE FERRY FLIGHTS.