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Updated: May 29, 2026
07:28
Evolution of Staircase Structures in Diffusive Convection
Published on: September 5, 2018
Laboratory simulations show diabatic heating drives cumulus-cloud evolution and entrainment
Roddam Narasimha1, Sourabh Suhas Diwan, Subrahmanyam Duvvuri
1Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India. roddam@caos.iisc.ernet.in
Summary
This study models cumulus cloud dynamics using bench-scale flows, revealing diabatic heating as a key driver of cloud development. Understanding this link between microphysics and turbulent dynamics improves climate models.
Area of Science:
- Atmospheric science
- Cloud physics
- Turbulent dynamics
Background:
- Clouds are a major source of uncertainty in climate modeling, particularly for tropical circulation.
- Connecting cloud microphysics to macroscale turbulent dynamics in cumulus clouds is a significant scientific challenge.
Purpose of the Study:
- To investigate the relationship between particulate microphysics and turbulent dynamics in cumulus clouds.
- To develop bench-scale models that simulate cumulus cloud forms and life cycles.
- To understand the role of diabatic heating in cloud development and entrainment.
Main Methods:
- Creation of bench-scale flows simulating various cumulus cloud forms and life cycles.
- Utilizing a transient plume model with volumetric diabatic heating to mimic latent heat release.
- Employing laser-based diagnostics for analyzing steady plumes and entrainment coefficients.
Main Results:
- Bench-scale flows successfully reproduced diverse cumulus cloud forms and tracked complete life cycles.
- Laser diagnostics identified Riehl-Malkus type protected cores in steady plumes.
- Diabatic heating was shown to influence the Taylor entrainment coefficient, increasing it near cloud base and decreasing it at higher levels, consistent with numerical simulations and aircraft observations.
Conclusions:
- In-cloud diabatic heating is identified as a critical factor driving cloud development.
- Diabatic heating may provide a crucial link between cloud microphysics and cloud-scale dynamics.
- Findings enhance understanding of cumulus cloud behavior and improve climate modeling accuracy.
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