RP 5: Statistics of Ice Nucleation Conditions in Mixed-Phase Clouds

Prof. Dr. Corinna Hoose

Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology

Assistance: Dr. Monika Niemand (Postcdoc), Dr. Luke Hande (Postdoc), Isabelle Reichardt (Doktorandin)

During INUIT Phase 1, RP5 focused on the transfer of novel laboratory-based ice nucleation parameterizations into a mesoscale model, their comparison to established parameterizations for case studies of orographic clouds, and the impact on the cloud properties.

The COSMO model has been extended by several state-of-the-art ice nucleation parameterizations (DeMott et al, 2010, 2014; Phillips et al, 2008, 2013; Niemand et al, 2012; Niedermeier et al, 2014) and a detailed comparison within the framework of idealized simulations of orographic clouds is currently being conducted. Furthermore, the model has been set up and run for a real case of the JFJ campaign during which a mixed-phase cloud was observed at the station. In addition RP5 has significantly contributed to several collaborative projects within INUIT. A comprehensive review of results of laboratory ice nucleation experiments was presented in Hoose and Möhler (2012) (collaboration of RP5 and RP7).

During INUIT Phase 2, this research project will elucidate the frequency of occurrence of the various heterogeneous ice nucleation processes in different mixed-phase clouds regimes which commonly occur in Mid-Europe. Furthermore, we study the possibility of achieving INP closure for the INUIT-2 Mediterranean field campaign together with WP-F and WP-L.

The project will be organized in four tasks:

• Update of the COSMO and later ICON-LES microphysics scheme by laboratory-based parameterizations of immersion, deposition and contact nucleation, tracking of in-droplet particles, and diagnostics
• Selection and setup of idealized case studies of stratiform, convective and orographic
• clouds representative for mixed-phase clouds in Europe
• Analysis of the simulations with respect to the location and magnitude of different ice
• nucleation processes
• INP closure study

More information about this project:

http://www.imk-tro.kit.edu/english/5609.php

References:

DeMott, P. J., Prenni, A. J., Liu, X., Kreidenweis, S. M., Petters, M. D., Twohy, C. H., M. S.
Richardson, T. Eidhammer & Rogers, D. C. (2010). Predicting global atmospheric ice nuclei distributions and their impacts on climate. Proceedings of the National Academy of Sciences,107(25), 11217-11222.
Phillips, V. T., DeMott, P. J., & Andronache, C. (2008). An empirical parameterization of
heterogeneous ice nucleation for multiple chemical species of aerosol. Journal of the
Atmospheric Sciences, 65(9), 2757-2783.
Phillips, V. T., Demott, P. J., Andronache, C., Pratt, K. A., Prather, K. A., Subramanian, R., &
Twohy, C. (2013). Improvements to an empirical parameterization of heterogeneous ice
nucleation and its comparison with observations. Journal of the Atmospheric Sciences, 70(2),378-409.
Niemand, M., O. Möhler, B. Vogel, H. Vogel, C. Hoose, P. Connolly, H. Klein, H. Bingemer, P.
DeMott, J. Skrotzki and T. Leisner (2012): A particle-surface-area-based parameterization of immersion freezing on desert dust particles. Journal of the Atmospheric Sciences 69, 3077-3092.
Niedermeier, D., Ervens, B., Clauss, T., Voigtländer, J., Wex, H., Hartmann, S., & Stratmann, F. (2014). A computationally efficient description of heterogeneous freezing: A simplified version ofthe Soccer ball model. Geophysical Research Letters, 41(2), 736-741.
Hoose, C. and O. Möhler (2012): Heterogeneous ice nucleation on atmospheric aerosols: A review of results from laboratory experiments. Atmospheric Chemistry and Physics 12, 9817-9854, doi:10.5194/acp-12-9817-2012