Entrainment & Mixing

How turbulent mixing affects cloud droplet size distributions

Entrainment and mixing are fundamental processes that shape cloud properties and influence precipitation. When dry air from outside the cloud is entrained and mixes with cloudy air, it can dramatically alter the droplet size distribution.

Key Questions

  • How does mixing transition from homogeneous to inhomogeneous during cloud lifecycle?
  • Under what conditions does mixing broaden vs. narrow the droplet size distribution?
  • How do environmental factors influence mixing characteristics?

Approach

I use high-resolution Lagrangian Cloud Model (LCM) simulations to track individual cloud droplets as they experience entrainment and mixing. This approach allows me to:

  1. Follow droplet trajectories through mixing events
  2. Quantify the evolution of droplet size distributions
  3. Identify mixing scenarios that lead to different outcomes
  • Lim & Hoffmann (2025): Aging of droplet size distribution in stratocumulus clouds. ACP (in review)
  • Lim & Hoffmann (2024): Life cycle evolution of mixing in shallow cumulus clouds. JGR: Atmospheres
  • Lim & Hoffmann (2023): Between broadening and narrowing: How mixing affects the width of the droplet size distribution. JGR: Atmospheres

References