A MULTI-SATELLITE OBSERVATIONAL ANALYSIS AND CMIP6 CLIMATE MODEL EVALUATION OF THE EVOLUTION OF CLOUDS, MOISTURE AND PRECIPITATION ON SUB-DAILY TO INTRASEASONAL TIMESCALES

WE PROPOSE TO MERGE AND LEVERAGE THE STRENGTHS OF AQUA SUOMI NPP AND OTHER SATELLITE RETRIEVALS (E.G. A-TRAIN SATELLITE PRODUCTS GPM TRMM) TO STUDY THE ENVIRONMENT COINCIDENT WITH THE TRANSITION FROM SHALLOW TO DEEP CONVECTION ON SUB-DAILY TO INTRASEASONAL TIMESCALES OVER THE TROPICAL OCEANS. FOR OUR FIRST OBJECTIVE WE DEMONSTRATE THE FEASIBILITY OF COMPUTING A MULTI-SENSOR RADIATIVE HEATING-INDUCED MOISTENING TERM FROM SPACE-BASED PLATFORMS FOR USE IN ANALYSES OF MOISTENING PROCESSES. IN OUR PROPOSAL WE PERFORM A PRELIMINARY CASE-STUDY ANALYSIS OF THE EVOLUTION OF MOISTURE DURING THREE MJO-ONSET EVENTS IN THE WESTERN INDIAN OCEAN. WE FIND A CLOSE COUPLING BETWEEN POSITIVE WATER VAPOR ANOMALIES IN THE LOWER TROPOSPHERE (FROM AQUA AIRS/AMSU) AND MULTI-SENSOR COMPUTED RADIATIVE MOISTENING ANOMALIES DURING MJO ONSET. THESE RESULTS MAY SUGGEST THAT RADIATIVE MOISTENING IS IMPORTANT FOR KEEPING THE ATMOSPHERE MOIST ENOUGH TO SUSTAIN DEEP CONVECTION ON SUFFICIENT TIMESCALES AND MAY BE RELEVANT FOR MJO ONSET TIMESCALES. OUR SECOND OBJECTIVE CENTERS ON USING NOVEL COMPOSITING STRATEGIES TO MAP TWICE-A-DAY SATELLITE SNAPSHOTS (E.G. AQUA AIRS/AMSU L2 RETRIEVALS) ONTO CONTINUOUS HOURLY SEQUENCES TO ANALYZE THE SUB-DAILY TIMESCALE EVOLUTION OF CONVECTION. EARLY RESULTS INDICATE WHEN THE LARGE-SCALE STATE IS MOIST ENOUGH THE TRANSITION FROM SHALLOW TO DEEP CONVECTIVE CLOUDS (AS IDENTIFIED FROM HIGH-RESOLUTION IR PRODUCTS) DOES NOT OCCUR EVERYWHERE. USING OUR NOVEL COMPOSITING STRATEGY RESULTS SUGGEST THAT THE MESOSCALE ENVIRONMENT ADJACENT TO DEEP CONVECTIVE INITIATION IS CHARACTERIZED BY INCREASED MOISTURE (AND LOCALIZED COOLING) UP TO SEVERAL HOURS PRIOR TO THE APPEARANCE OF DEEP CONVECTIVE CLOUDS (RELATIVE TO NON-DEEP-CONVECTIVE-INITIATION AREAS