Ice microphysical processes exert a strong control on the simulated radiative energy budget in the tropics

Author(s)
Sylvia C. Sullivan, Aiko Voigt
Abstract

Simulations of the global climate system at storm-resolving resolutions of 2 km are now becoming feasible and show promising realism in clouds and precipitation. However, shortcomings in their representation of microscale processes, like the interaction of cloud droplets and ice crystals with radiation, can still restrict their utility. Here, we illustrate how changes to the ice microphysics scheme dramatically alter both the vertical profile of cloud-radiative heating and top-of-atmosphere outgoing longwave radiation (terrestrial infrared cooling) in storm-resolving simulations over the Asian monsoon region. Poorly-constrained parameters in the ice nucleation scheme, overactive conversion of ice to snow, and inconsistent treatment of ice crystal effective radius between microphysics and radiation alter cloud-radiative heating by a factor of four and domain-mean infrared cooling by 30 W m−2. Vertical resolution, on the other hand, has a very limited impact. Even in state-of-the-art models then, uncertainties in microscale cloud properties exert a strong control on the radiative budget that propagates to both atmospheric circulation and regional climate. These uncertainties need to be reduced to realize the full potential of storm-resolving models.

Organisation(s)
Department of Meteorology and Geophysics
External organisation(s)
Institute of Meteorology and Climate Research, Columbia University in the City of New York
Journal
Communications Earth & Environment
Volume
2
No. of pages
8
ISSN
2662-4435
DOI
https://doi.org/10.1038/s43247-021-00206-7
Publication date
07-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
105204 Climatology, 105206 Meteorology
Keywords
ASJC Scopus subject areas
General Environmental Science, General Earth and Planetary Sciences
Sustainable Development Goals
SDG 13 - Climate Action
Portal url
https://ucrisportal.univie.ac.at/en/publications/4516f965-f6f0-4126-89f8-c741d33b4689