Earth Science Seminar Observations and Analysis of Fine-scale Microphysics in Weakly Turbulent Clouds Presented by Alex Kostinski Michigan Technological University Thursday, May 2, 2019 11:00 A.M. in 233-305E and on Webex Abstract Several aspects of recent in-situ aircraft observations of weakly turbulent clouds will be discussed. Droplet clustering is relevant to precipitation formation and radiative transfer but has not been quantified. I will review recent data gathered by an airborne holographic instrument used to explore the three-dimensional spatial statistics of cloud droplet positions in homogeneous stratiform boundary-layer clouds. The measured 3D radial distribution function suggests droplet clustering on cm scales. The measurements also reveal a surprisingly large contribution in the pre-drizzle size range of 40–80 μm (transition droplets, or drizzlets), a range seldom measured and assumed to reside in a condensation‐to‐collision minimum between cloud droplet and drizzle modes. Implication of this surprisingly large contribution of drizzlets will be discussed. I will then move on to drizzle. Most drizzling stratocumulus clouds form drizzle virga below cloud base. I will conclude with a recent confirmation of a simple analytical relationship between drizzle rate and cloud thickness. JPL Contact: Anthony Davis (4-0450) About the Speaker Alex Kostinski is currently a professor of physics at Michigan Technological University, where he has been since 1989. He received a B.S. in mathematics in 1978 from the Hebrew University of Jerusalem, and a Ph.D. in physics in 1984 from the University of Illinois, Chicago. During 1985-9 he was a postdoctoral fellow at the UIC Electrical Engineering Department. Topics of his publications include cloud, aerosol, and precipitation physics; turbulence; radar meteorology; exoplanet detection; wave propagation in random media; and adaptive and polarization optics, and time series analysis. His research interests continue to evolve with current focus on stochastic processes of physical and radar meteorology. The research has been supported mostly by the National Science Foundation.   Site Manager: Webmaster: CL 08-3220