Cloud Feedback on Earth's Long-Term Climate Simulated by a Near-Global Cloud-Permitting Model
- 1Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China (yanmy@pku.edu.cn)
- 2Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA (yixiaoz@mit.edu)
- 3Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, QC, Canada (han.huang2@mcgill.ca)
The Sun becomes brighter with time, but Earth's climate is roughly temperate for life during its long-term history; for early Earth, this is known as the faint young Sun problem (FYSP). Besides the carbonate-silicate feedback, recent researches suggest that a long-term cloud feedback may partially solve the FYSP. However, the general circulation models they used cannot resolve convection and clouds explicitly. This study re-investigates the clouds using a near-global cloud-permitting model without cumulus convection parameterization. Our results confirm that a stabilizing shortwave cloud feedback does exist, and its magnitude is ≈6 W m−2 or 14% of the energy required to offset a 20% fainter Sun than today, or ≈10 W m−2 or 16% for a 30% fainter Sun. When insolation increases and meanwhile CO2 concentration decreases, low-level clouds increase, acting to stabilize the climate by raising planetary albedo, and vice versa.
How to cite: Yan, M., Yang, J., Zhang, Y., and Huang, H.: Cloud Feedback on Earth's Long-Term Climate Simulated by a Near-Global Cloud-Permitting Model, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-4127, https://doi.org/10.5194/egusphere-egu23-4127, 2023.
