New Aerosol-sensitive Heterogeneous Ice Nucleation Parameterization in the EC-Earth3 Earth System Model: evaluation and climate response
- 1Barcelona Supercomputing Center, Earth Sciences, Barcelona, Spain
- 2Universitat Politècnica de Catalunya, Project and Construction Engineering, Barcelona, Spain
- 3Environmental Chemical Processes Laboratory (EPCL), University of Crete, Department of Chemistry, Heraklion, Greece
- 4Foundation for Research and Technology, Center for the Study of Air Quality and Climate Change (C-STACC), Institute of Chemical Engineering Sciences (ICE-HT), Patras, Greece
- 5Ecole Polytechnique Federale de Lausanne, School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory of Atmospheric Processes and their Impacts (LAPI), Lausanne, Switzerland
- 6Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Athens, Greece
- 7Royal Netherlands Meteorological Institute, De Bilt, Netherlands
- 8ICREA, Catalan Institution for Research and Advanced Studies, Barcelona, Spain
Clouds are large contributors to uncertainty in climate projections, with aerosol-cloud interactions playing a key role. To better reproduce heterogeneous ice clouds and, ultimately, the Earth’s changing energy budget in EC-Earth3 (one of the CMIP6 Earth System Models), its heterogeneous ice nucleation scheme has been updated. Specifically, the temperature-based parameterization has been substituted by a combination of aerosol-and-temperature-sensitive ice nucleating parameterizations. In particular, the model now considers a dust-and-soot-sensitive deposition nucleation scheme for cirrus clouds and aerosol-sensitive immersion freezing schemes for mixed-phase clouds. The latter is sensitive to the mineralogical composition of dust, specifically to the content of K-feldspar and quartz, and to marine organic aerosols, which are explicitly traced in EC-Earth3. Moreover, a secondary ice production parameterization based on a random forest regressor enhances the ice formed by the primary processes.
We evaluate the model against an extended observational dataset of INP concentrations and analyze the effect of modelled aerosols upon heterogeneous ice nucleation in mixed-phase clouds and cirrus clouds produced with the new parameterizations. We also investigate the sensitivity of the simulated liquid and ice water content and the atmospheric radiative fluxes to the two different soil mineralogy atlases. Additionally, we use this updated model version to study in more detail a severe dust intrusion event that produced dust-infused clouds that affected Europe in March 2022.
The results with the new ice nucleation parameterizations show a clear association of the simulated ice crystal number concentrations with the aerosol sources and transported regions. We also show that replacing the temperature-dependent ice nucleation parameterization with an aerosol-sensitive parameterization in EC-Earth3 significantly impacts surface temperature at high latitudes.
How to cite: Costa-Surós, M., Gonçalves, M., Chatziparaschos, M., Georgakaki, P., Ilić, L., Montane, G., Myriokefalitakis, S., van Noije, T., Le Sager, P., Kanakidou, M., Nenes, A., and Pérez García-Pando, C.: New Aerosol-sensitive Heterogeneous Ice Nucleation Parameterization in the EC-Earth3 Earth System Model: evaluation and climate response, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13040, https://doi.org/10.5194/egusphere-egu23-13040, 2023.
