1. Cloud Physics Breakout Science Questions/Issues: Driving factors/relative importance of these factors in understanding precipitation formation needs to be better understood/characterized through measurements Cloud/Aerosol interaction: Aerosol impact on warm rain processes, ccn, giant aerosol Aerosol impact on ice formation in clouds, biological, where ice forms, concentration of ice Cloud impacts on aerosol, cloud processing Cloud Particle/Precipitation growth: Drizzle formation/coalescence, growth to larger particles, effects of turbulence Growth of ice in clouds Observations of supercooled water/mixed phase clouds

2. Cloud Physics Breakout Science Questions/Issues: Driving factors/relative importance of these factors in understanding precipitation formation needs to be better understood/characterized through measurements Cloud Transport: Vertical transport of chemical species through the troposphere Transport/dispersion within cloud (Cloud entrainment processes)

3. Cloud Physics Breakout Measure Needs: Many of the in situ measurements are based on “old” technology with incremental improvements over the years A recognized need for improved measurements of state parameters in clouds: Humidity in and around clouds, temperature measurements in cloud—discussion of radiometric techniques & absorption techniques: development of technologies & production level instruments

4. Cloud Physics Breakout Measure Needs: Many of the in situ measurements are based on “old” technology with incremental improvements over the years Characterization & Calibration of instruments: Need to develop “standard” for cloud physics measurements, within a laboratory setting Development of a new facility or access to existing facilities that can simulate cloud conditions/aircraft speeds for calibration, characterization, comparison, & development Flow modeling—flow around aircraft and flow in and through instruments & inlets

5. Cloud Physics Breakout Remote Sensing: Complimentary measurements from multiple remote sensors and/or combined remote sensing & in situ capabilities Precipitation radars on aircraft (C130 & N2UW) Combination of lidar & radars for multi-parameter retrievals (and/or multi-wavelength radars) Use of radiometric techniques to constrain radar/lidar measurements & retrievals (airborne and surface-based application)