Radiative Heating of High-Level Clouds and Its Impacts on Climate
- Author(s)
- Kerstin Haslehner, Blaž Gasparini, Aiko Voigt
- Abstract
The interactions of clouds with radiation influence climate. Many of these impacts appear to be related to the radiative heating and cooling from high-level clouds, but few studies have explicitly tested this. Here, we use simulations with the ICON-ESM model to understand how high-level clouds, through their radiative heating and cooling, influence the large-scale atmospheric circulation and precipitation in the present-day climate. We introduce a new method to diagnose the radiative heating of high-level clouds: instead of defining high-level clouds as all clouds at temperatures colder than −35°C, we define them as all clouds with a cloud top at temperatures colder than −35°C. The inclusion of the lower cloud parts at temperatures warmer than −35°C circumvents the creation of artificial cloud boundaries and strong artificial radiative heating at the temperature threshold. To isolate the impact of high-level clouds, we analyze simulations with active cloud-radiative heating, with the radiative heating from high-level clouds set to zero, and with the radiative heating from all clouds set to zero. We show that the radiative interactions of high-level clouds warm the troposphere and strengthen the eddy-driven jet streams, but have no impact on the Hadley circulation strength and the latitude of the Intertropical Convergence Zone. Consistent with their positive radiative heating and energetic arguments, high-level clouds reduce precipitation throughout the tropics and lower midlatitudes. Overall, our results confirm that the radiative interactions of high-level clouds have important impacts on climate and highlight the need for better representing their radiative interactions in models.
- Organisation(s)
- Department of Meteorology and Geophysics
- Journal
- Journal of Geophysical Research: Atmospheres
- Volume
- 129
- ISSN
- 2169-897X
- DOI
- https://doi.org/10.1029/2024JD040850
- Publication date
- 06-2024
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105204 Climatology
- Keywords
- ASJC Scopus subject areas
- Geophysics, Atmospheric Science, Space and Planetary Science, Earth and Planetary Sciences (miscellaneous)
- Sustainable Development Goals
- SDG 13 - Climate Action
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/0c4ce658-be98-4700-9e69-19a964f313e4