RESEARCH SCANNING POLARIMETER (RSP) TEAM SUPPORT FOR CAMP2EX

THE CLOUDS AEROSOL AND MONSOON PROCESSES-PHILIPPINES EXPERIMENT (CAMP2EX) AIMS TO PROVIDE A DETAILED VIEW OF THE MICROPHYSICS OF AEROSOLS AND CLOUDS IN ADDITION TO ATMOSPHERIC STATE IN THE VICINITY OF THE PHILIPPINES DURING THE SOUTHWEST MONSOON. THE AIRBORNE OBSERVATIONS WILL ALLOW ENHANCING OUR UNDERSTANDING OF THE COMPLEX INTERACTIONS BETWEEN AEROSOLS CLOUDS AND ATMOSPHERIC CONDITIONS. HERE WE PROPOSE TO INCLUDE THE RESEARCH SCANNING POLARIMETER (RSP) INTO THE CAMPAIGN S INSTRUMENT SUITE SINCE THE RSP S UNIQUE COMBINATION OF MULTI-DIRECTIONAL TOTAL AND POLARIZED REFLECTANCES AT VISIBLE AND SHORTWAVE INFRARED WAVELENGTHS AND WITH DENSE ANGULAR SAMPLING PROVIDES CAPABILITIES TO ADDRESS MANY OF THE CAMP2EX OBSERVATIONAL OBJECTIVES. CLOUD PRODUCTS THAT THE RSP DELIVERS OPERATIONALLY INCLUDE CLOUD TOP HEIGHT CLOUD TOP PHASE CLOUD OPTICAL THICKNESS LIQUID DROP SIZE DISTRIBUTION AND THE EFFECTIVE RADIUS SHAPE ROUGHNESS AND ASYMMETRY PARAMETER OF ICE CRYSTALS. RSP RETRIEVALS FOR AEROSOLS PROVIDE AEROSOL OPTICAL DEPTH LAYER HEIGHT EFFECTIVE RADIUS AND VARIANCE OF THE SIZE DISTRIBUTION THE COMPLEX REFRACTIVE INDEX AND THE FRACTION OF NON-SPHERICAL PARTICLES. ALL AEROSOL MICROPHYSICAL PARAMETERS ARE OBTAINED FOR TWO MODES. POLARIMETRIC CLOUD DROPLET SIZE RETRIEVALS ARE HIGHLY ROBUST IN THE SPATIAL INHOMOGENEOUS CLOUD CONDITIONS LIKELY ENCOUNTERED DURING CAMP2EX. RELATIVELY ACCURATE AEROSOL RETRIEVALS CAN ALSO BE OBTAINED IN BETWEEN BROKEN CLOUDS USING POLARIMETRY. FURTHERMORE THE RSP MEASURES IN SHORTWAVE INFRARED BANDS THAT PROVIDE TRADITIONAL RETRIEVALS OF CLOUD PARTICLE SIZES WHICH ALLOWS ADDRESSING THE CAMP2EX GOAL TO STUDY POTENTIAL PARTICLE SIZE BIASES OBTAINED WITH SUCH SHORTWAVE INFRARED MEASUREMENTS IN INHOMOGENEOUS CONDITIONS. RSP HAS FLOWN TWO PREVIOUS MISSIONS ON THE P3 AIRCRAFT SELECTED FOR CAMP2EX AND AN INTERFACE AND ALL CONNECTORS AND CABLES FOR THE INTEGRATION ARE READILY AVAILABLE LEADING TO MINIMAL INTEGRATION COSTS. IN ADDITION TO PROVIDING QUALITY-ASSURED LEVEL-1 AND OPERATIONAL LEVEL-2 PRODUCTS WE PROPOSE TO FURTHER DEVELOP AND EVALUATE SEVERAL OTHER PRODUCTS THAT ARE HIGHLY RELEVANT TO THE CAMP2EX OBJECTIVES. SPECIFICALLY PROPOSED ARE TECHNIQUES (1) TO ESTIMATE THE RELATIVE EXTINCTION OF LIQUID AND ICE IN MIXED-PHASE CLOUD TOPS; (2) TO REPRODUCE 2D SHAPES OF OBSERVED CUMULUS CLOUDS AND (3) TO RETRIEVE DROPLET SIZE PROFILES FROM SIDE VIEWS OF ISOLATED CLOUDS. TO AID THE DEVELOPMENT OF SUCH PRODUCTS AND TO EVALUATE RSP PRODUCTS IN GENERAL WE ALSO PROPOSE TO CONSTRUCT AN RSP MEASUREMENTS SIMULATOR BASED ON 3D RADIATIVE TRANSFER AND CLOUD MODEL OUTPUT. AS PART OF OUR INITIAL ANALYSIS OF THE RSP RETRIEVALS WE PROPOSE TO INVESTIGATE CORRELATIONS BETWEEN AEROSOL AND CLOUD PROPERTIES UNDER VARYING CONDITIONS WHICH COINCIDES WITH THE PRIMARY GOAL OF THE CAMP2EX CAMPAIGN.