How does cloud-radiative heating over the North Atlantic change with grid spacing, convective parameterization, and microphysics scheme in ICON version 2.1.00?

Author(s)
Sylvia Sullivan, Behrooz Keshtgar, Nicole Albern, Elzina Bala, Christoph Braun, Anubhav Choudhary, Johannes Hörner, Hilke Lentink, Georgios Papavasileiou, Aiko Voigt
Abstract

Cloud-radiative heating (CRH) within the atmosphere and its changes with warming affect the large-scale atmospheric winds in a myriad of ways, such that reliable predictions and projections of circulation require reliable calculations of CRH. In order to assess the sensitivities of upper-tropospheric midlatitude CRH to model settings, we perform a series of simulations with the ICOsahedral Nonhydrostatic Model (ICON) over the North Atlantic using six different grid spacings, parameterized and explicit convection, and one- versus two-moment cloud microphysics. While sensitivity to grid spacing is limited, CRH profiles change dramatically with microphysics and convection schemes. These dependencies are interpreted via decomposition into cloud classes and examination of cloud properties and cloud-controlling factors within these different classes. We trace the model dependencies back to differences in the mass mixing ratios and number concentrations of cloud ice and snow, as well as vertical velocities. Which frozen species are radiatively active and the broadening of the vertical velocity distribution with explicit convection turn out to be crucial factors in altering the modeled CRH profiles.

Organisation(s)
Department of Meteorology and Geophysics
External organisation(s)
Karlsruher Institut für Technologie, National Observatory of Athens, University of Arizona, Institute of Meteorology and Climate Research, AON
Journal
Geoscientific Model Development
Volume
16
Pages
3535–3551
No. of pages
17
ISSN
1991-959X
DOI
https://doi.org/10.5194/gmd-16-3535-2023
Publication date
06-2023
Peer reviewed
Yes
Austrian Fields of Science 2012
105206 Meteorology
ASJC Scopus subject areas
General Earth and Planetary Sciences, Modelling and Simulation
Portal url
https://ucrisportal.univie.ac.at/en/publications/b5123263-2fab-4f05-8015-580886b53d62