Document Type
Article
Publication Date
8-4-2026
Department
Department of Physics
Abstract
The size and spatial clustering of water droplets in warm clouds influence cloud evolution and radiation properties and thus are of fundamental importance for the Earth’s energy balance and water cycle. Some proposed mechanisms for droplet growth and precipitation initiation in warm clouds require strong droplet clustering. Resolving such clustering on sub-cm scales remains a challenge. The most detailed observations, collected from aircraft, showed weak mm-scale droplet clustering averaged over kilometer scales in stratocumulus clouds. Here we present spatially resolved in-situ holographic measurements from a tethered aerostat, demonstrating that clustering in shallow cumulus clouds is significantly stronger and far more localized than previously thought. These findings challenge current cloud microphysics frameworks, with implications for precipitation initiation and cloud modeling.
Publication Title
Proceedings of the National Academy of Sciences of the United States of America
Recommended Citation
Thiede, B.,
Larsen, M.,
Nordsiek, F.,
Schlenczek, O.,
Kim, Y.,
Bodenschatz, E.,
&
Bagheri, G.
(2026).
Highly localized droplet clustering in shallow cumulus clouds.
Proceedings of the National Academy of Sciences of the United States of America,
123(32).
http://doi.org/10.1073/pnas.2602976123
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/2902
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
Copyright © 2026 the Author(s). Published by PNAS. Publisher’s version of record: https://doi.org/10.1073/pnas.2602976123