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Updated: May 14, 2026
13:27
Exploring the Effects of Atmospheric Forcings on Evaporation: Experimental Integration of the Atmospheric Boundary Layer and Shallow Subsurface
Published on: June 8, 2015
Opposing transient and equilibrium effective radiative forcing from aerosol-cloud interactions.
1Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University, Jerusalem, Israel. guy.dagan@mail.huji.ac.il.
Nature Communications
|May 12, 2026
Summary
Aerosol-cloud interactions (ACI) show a transient positive effect on Earth's radiation budget, but shift to a negative equilibrium. This time-dependent response, including hysteresis, impacts effective radiative forcing (ERF) estimates.
Area of Science:
- Atmospheric Science
- Climate Science
- Earth System Science
Background:
- Aerosols significantly influence clouds and Earth's radiation budget.
- Aerosol-cloud interactions (ACI) represent a major uncertainty in climate forcing estimates.
Purpose of the Study:
- To investigate the time-dependent response of local, convection-focused effective radiative forcing due to aerosol-cloud interactions (ERF_ACI).
- To understand how varying aerosol perturbation timescales affect ERF_ACI and its equilibrium state.
Main Methods:
- Utilized an ensemble of high-resolution simulations with instantaneous and time-varying aerosol perturbations.
- Analyzed simulations initialized from different atmospheric states to capture transient and equilibrium responses.
Main Results:
- Transient ERF_ACI is positive within the first two days, driven by microphysical changes and enhanced cloud cover.
- Equilibrium ERF_ACI becomes negative due to increased atmospheric stability and reduced anvil clouds.
- Hysteresis is observed in intermediate regimes, where ERF_ACI depends on aerosol loading history.
Conclusions:
- The time-mean ERF_ACI is dependent on the ratio of environmental adjustment to aerosol perturbation timescales.
- Snapshot observations and equilibrium-based models may misestimate ERF_ACI due to neglecting time-dependent effects and hysteresis.
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