Droplet growth by gravitational coagulation enhanced by turbulence: Comparison of theory and measurements

Nicole Riemer, A. S. Wexler, K. Diehl

Research output: Contribution to journalArticlepeer-review


While it is well known that cloud droplets grow in an inherently turbulent environment, the role of turbulence is only now being elucidated. To shed light on this issue, we compare published measurements of droplet growth by collision in turbulent flow with numerical simulations. Because the measurements demonstrate an accelerated growth under turbulent conditions compared to laminar ones, the data clearly cannot be reproduced using the well-established kernel for sedimentation under laminar conditions. By employing a collision kernel that has been recently derived from direct numerical simulations, we perform sensitivity studies and quantify the parameter ranges that are compatible with the experimental data. This experiment does not enable us to uniquely determine the model parameters but we were able to place constraints on the form of acceptable models that reproduce the experimental data successfully. Moreover, we gain insight into how laboratory experiments could be improved to aid model validation.

Original languageEnglish (US)
Article numberD07204
JournalJournal of Geophysical Research Atmospheres
Issue number7
StatePublished - Apr 16 2007
Externally publishedYes

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology


Dive into the research topics of 'Droplet growth by gravitational coagulation enhanced by turbulence: Comparison of theory and measurements'. Together they form a unique fingerprint.

Cite this