THE FOLLOWING THREE OVERARCHING RESEARCH THEMES WERE OUTLINED AND EXHAUSTIVELY DESCRIBED IN THE ORIGINAL PMM PROPOSAL: 1. CREATE A GPM SNOWFALL CENSUS AND EVALUATE WITH INDEPENDENT DATASETS. 2. INVESTIGATE THE COMBINED RADAR AND MICROWAVE RADIOMETER RESPONSE TO DIFFERENT SNOWFALL MODES USING GPM AND INDEPENDENT OBSERVATIONS. 3. COLLECT EXTENDED COINCIDENT GROUND-BASED RADAR AND SNOW MICROPHYSICAL OBSERVATIONS. WE INTEND TO FOCUS ON THESE THREE RESEARCH FOCUS AREAS IN THE UPDATED MICHIGAN TECHNOLOGICAL UNIVERSITY WORK PLAN WITH SPECIFIC TASKS OUTLINED BELOW. THE FOLLOWING TASK DESCRIPTIONS INCLUDE REFERENCES TO SECTIONS IN THE ORIGINAL PMM PROPOSAL. 1. SECTION 5.1.1 AND 5.1.2 (GPM GLOBAL SNOWFALL MAPPING AND EVALUATION PLUS SHALLOW SNOWFALL ANALYSIS AND GPROF A PRIORI DATABASE STUDIES) IS A CORE ACTIVITY BUT THE GPM A PRIORI DATABASE SENSITIVITY TESTS WILL NOT BE UNDERTAKEN DUE TO THE SIGNIFICANT SPIN-UP TIME INVOLVED WITH LEARNING INSTALLING AND RUNNING GPROF ON OUR LOCAL COMPUTING SYSTEMS. WE WILL PLAY AN ANCILLARY ROLE IN SUCH TESTING IF IT IS DEEMED IMPORTANT BY OTHER SCIENCE TEAM MEMBERS BUT WILL REFRAIN FROM LEADING THIS ACTIVITY. GPM GLOBAL SNOWFALL MAPPING AND EVALUATING AGAINST INDEPENDENT DATASETS WILL BE THE PRIMARY ACTIVITY UNDERTAKEN ESPECIALLY SINCE SIGNIFICANT PROGRESS HAS BEEN MADE IN RECENT MONTHS ON THIS TOPIC. WE ARE CURRENTLY WORKING WITH COLLABORATORS G. SKOFRONICK-JACKSON S. J. MUNCHAK AND N. WOOD ON COMPARING GPM RADAR AND RADIOMETER DATASETS AGAINST INDEPENDENT CLOUDSAT AND MODELING/REANALYSIS DATASETS. 2. SECTION 5.1.3: WE WILL COLLABORATE WITH OTHER GPM SCIENCE TEAM MEMBERS ON THIS TOPIC AND PROPOSE TO PLAY AN ANCILLARY ROLE IN THIS TASK. WE ARE STILL VERY INTERESTED IN STUDYING POTENTIAL SYSTEMATIC MULTI-FREQUENCY MICROWAVE SIGNATURES OF DIFFERENT SNOWFALL TYPES. THE PRE-GPM DATASETS AND SOME INITIAL ANALYSES HAVE RECENTLY BEEN COMPLETED THUS THEY CAN BE REMOVED FROM THE FUTURE TASK LIST. WE WILL STILL HOWEVER EXPLORE THE HIGHFREQUENCY (89 AND 166 GHZ) SCATTERING INDEX STUDIES USING GPM OBSERVATIONS. WE WILL WORK WITH PMM COLLABORATORS G. PETTY AND G. PANEGROSSI ON THIS TOPIC. 3. SECTION 5.2: THIS IS AN EXTREMELY LOW-COST BUT ARGUABLY HIGH IMPACT COMPONENT OF OUR PROPOSED WORK. EXTENDED DATASETS OF COMBINED GROUND-BASED ICE MICROPHYSICS AND RADAR OBSERVATIONS ARE RARE SO WE WILL CONTINUE TO COLLECT DATA AT OUR MARQUETTE MI OBSERVATORY WITH SUPPORT FROM THE NATIONAL WEATHER SERVICE. WE WILL PRIORITIZE THE FOLLOWING MRR/PIP ACTIVITIES: A. STUDYING SYSTEMATIC MICROPHYSICAL DIFFERENCES BETWEEN DIFFERENT SNOWFALL MODES AND IMPACTS ON RADAR/RADIOMETER SIGNALS. B. FORWARD MODELING STUDIES USING ICE MODELS COMBINED WITH ICE PARTICLE SIZE DISTRIBUTIONS TO STUDY OPTIMAL ICE MODELS TO SIMULATE RADAR/RADIOMETER SIGNALS. C. LOW-LEVEL BLIND ZONE STATISTICS TO STUDY SPACEBORNE PRECIPITATION RATE BIASES FOR DIFFERENT TYPES COLD-SEASON PRECIPITATION EVENTS. FURTHERMORE WE WILL WORK WITH PMM COLLABORATORS W. PETERSEN A. TOKAY AND D. WOLFF TO SUPPORT A PLUVIO PRECIPITATION GAUGE DEPLOYMENT NEAR OUR MRR/PIP DEPLOYMENT SITE IN MARQUETTE MI TO STUDY SNOWFALL VARIABILITY WITHIN A TYPICAL RADIOMETER FOOTPRINT SIZE. THE FOLLOWING PROPOSAL SUMMARY/STATEMENT OF WORK THEREFORE STILL RETAINS ITS ORIGINAL OVERALL MESSAGE ALBEIT WITH THE STREAMLINED TASKS OUTLINED ABOVE: THE GLOBAL PRECIPITATION MEASUREMENT MISSION HAS SUCCESSFULLY COLLECTED THE FIRST COMBINED MICROWAVE RADIOMETER AND DUAL-FREQUENCY PRECIPITATION MEASUREMENTS INCLUDING FREQUENTLY SAMPLING SURFACE SNOWFALL EVENTS IN THE EXTRATROPICS. SINCE SNOWFALL PLAYS A VITAL ROLE IN THE EARTH S ENERGETICS AND HYDROLOGY EVALUATING AND ADVANCING GPM S SNOWFALL DETECTION AND SNOWFALL RATE RETRIEVAL CAPABILITIES ARE HIGH PRIORITY TASKS TO ENSURE HIGH-QUALITY GPM DATASETS. THIS PROJECT WILL THEREFORE UTILIZE PRECIPITATION RETRIEVALS FROM GPM AND AFFILIATED GPM CONSTELLATION SENSORS AS WELL AS INDEPENDENT SPACEBORNE MODELING AND GROUND-BASED DATASETS TO CON