- 1Hebrew University of Jerusalem, Israel (guy.dagan@mail.huji.ac.il)
- 2Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado, USA
- 3Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, OX1 3PU, UK
- 4Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ 08540, USA
- 5Institute of Meteorology and Climate Research Troposphere Research (IMKTRO) Karlsruhe Institute of Technology, Germany
- 6LAERO, Université de Toulouse, CNRS, IRD, Toulouse, France
- 7Department of Geoscience and Remote Sensing, Delft University of Technology, The Netherlands
- 8Environmental Science Division, Argonne National Laboratory, Lemont, Illinois, USA
- 9Department of Meteorology and Geophysics, Faculty of Earth Sciences, Geography and Astronomy, University of Vienna, Vienna, Austria
- 10Indian Institute of Tropical Meteorology, Pune, India
- 11Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
- 12Meteorology and Air Quality Group, Wageningen University and Research, Wageningen, The Netherlands
- 13Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, USA
Aerosol-cloud interactions are a persistent source of uncertainty in climate research. This study presents findings from a model intercomparison project examining the impact of aerosols on clouds and climate in "cloud-resolving" Radiative-Convective Equilibrium (RCE) simulations. Specifically, 11 different models conducted RCE simulations under varying aerosol concentrations, domain configurations, and sea surface temperatures (SSTs). We analyze the response of domain-mean cloud and radiative properties to imposed aerosol concentrations across different SSTs. Additionally, we explore the potential impact of aerosols on convective aggregation and large-scale circulation in large-domain simulations.
The results reveal that the cloud and radiative responses to aerosols vary substantially across models. However, a common trend across models, SSTs, and domain configurations is that increased aerosol loading tends to suppress warm rain formation, enhance cloud water content in the mid-troposphere, and consequently increase mid-tropospheric humidity and upper-tropospheric temperature, impacting static stability. The warming of the upper troposphere can be attributed to reduced entrainment effects due to the higher environmental humidity in the mid-troposphere. However, examining high percentiles of vertical velocities at the mid troposphere do not demonstrate convective invigoration. In large-domain simulations, where convection tends to self-organize, aerosol loading does not influence self-organization but tends to reduce the intensity of large-scale circulation forming between convective clusters and dry regions. This reduction in circulation intensity can be explained by the increase in static stability.
How to cite: Dagan, G., van den Heever, S. C., Stier, P., Abbott, T. H., Barthlott, C., Chaboureau, J.-P., de Roode, S., Fan, J., Gasparini, B., Hoose, C., Jansson, F., Kulkarni, G., Leung, G., Prabhakaran, T., Romps, D. M., Shum, D., Tijhuis, M., van Heerwaarden, C. C., Wing, A., and Yunpeng, S.: RCEMIP-ACI: Aerosol-Cloud Interactions in a Multimodel Ensemble of Radiative-Convective Equilibrium Simulations , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9604, https://doi.org/10.5194/egusphere-egu25-9604, 2025.
