EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Secondary ice production in NorESM2 climate model: quantifying the impact on Arctic clouds

Georgia Sotiropoulou1,2, Anna Lewinschal1, Annica Ekman1, and Athanasios Nenes2,3
Georgia Sotiropoulou et al.
  • 1Department of Meteorology, Stockholm University, Stockholm, Sweden
  • 2École polytechnique fédérale de Lausanne, Environmental Engineering, Laboratory of Atmospheric Processes and their Impacts, Lausanne, Switzerland
  • 3Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras, Greece

Arctic clouds are among the largest sources of uncertainty in predictions of Arctic weather and climate. This is mainly due to errors in the representation of the cloud thermodynamic phase and the associated radiative impacts, which largely depends on the parameterization of cloud microphysical processes. Secondary ice processes (SIP) are among the microphysical processes that are poorly represented, or completely absent, in climate models. In most models, including the Norwegian Earth System Model -version 2 (NorESM2), Hallet-Mossop (H-M) is the only SIP mechanism available. In this study we further improve the description of H-M and include two additional SIP mechanisms (collisional break-up and drop-shattering) in NorESM2. Our results indicate that these additions improve the agreement between observed and modeled ice crystal number concentrations and liquid water path in mixed-phase clouds observed at Ny-Alesund in 2016-2017. We then conclude by quantifying the impact of these overlooked SIP mechanisms for cloud microphysical characteristics, properties and the radiative balance throughout the Arctic.


How to cite: Sotiropoulou, G., Lewinschal, A., Ekman, A., and Nenes, A.: Secondary ice production in NorESM2 climate model: quantifying the impact on Arctic clouds, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10241,, 2021.


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