Thermodynamic control of anvil cloud amount
- Paris-Sorbonne and Pierre-and-Marie Curie (UPMC) Univ., Paris (France). Dynamic Meteorology Lab. (LMD)/Inst. Pierre Simon Laplace (IPSL)
- Max-Planck Inst. for Meteorology, Hamburg (Germany)
- Stony Brook Univ., NY (United States). School of Marine and Atmospheric Sciences
- Columbia Univ., New York, NY (United States). Lamont–Doherty Earth Observatory
- National Center for Atmospheric Research, Boulder, CO (United States). Climate and Global Dynamics Lab.
General circulation models show that as the surface temperature increases, the convective anvil clouds shrink. By analyzing radiative–convective equilibrium simulations, our work shows that this behavior is rooted in basic energetic and thermodynamic properties of the atmosphere: As the climate warms, the clouds rise and remain at nearly the same temperature, but find themselves in a more stable atmosphere; this enhanced stability reduces the convective outflow in the upper troposphere and decreases the anvil cloud fraction. By warming the troposphere and increasing the upper-tropospheric stability, the clustering of deep convection also reduces the convective outflow and the anvil cloud fraction. When clouds are radiatively active, this robust coupling between temperature, high clouds, and circulation exerts a positive feedback on convective aggregation and favors the maintenance of strongly aggregated atmospheric states at high temperatures. This stability iris mechanism likely contributes to the narrowing of rainy areas as the climate warms. Whether or not it influences climate sensitivity requires further investigation.
- Research Organization:
- Univ. Corp. for Atmospheric Research (UCAR), Boulder, Co (United States)
- Sponsoring Organization:
- Office of Science (SC), Biological and Environmental Research (BER). Earth and Environmental Systems Science Division; National Centre for Scientific Research (CNRS), Strasbourg (France); National Research Agency (ANR); Max-Planck Society; German Research Foundation (DFG)
- Grant/Contract Number:
- FC02-97ER62402; ANR-10-LABX-0018; VO 1765/3-1
- OSTI ID:
- 1262439
- Alternate ID(s):
- OSTI ID: 1438340
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 113 Journal Issue: 32; ISSN 0027-8424
- Publisher:
- National Academy of Sciences, Washington, DC (United States)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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