HINC

Based on the design of the University of Toronto Continuous Flow Diffusion Chamber (UT-CFDC) the Horizontal Ice Nucleation Chamber HINC is particularly designed to study the ability of ambient aerosols to activate as ice nucleating particles (INPs). Especially in the context of a changing climate, the influence of ice and mixed-phase clouds on the Earth’s radiation budget remains one of the largest uncertainties. Therefore not only a better understanding of general ice crystal formation mechanisms is needed, but it is also highly important to quantify the ice nucleating ability of ambient aerosols. In this context, conducting field measurements is the only way forward.

HINC is one of the two portable ice nucleation chambers in our group and is operated at the external page High Alpine Research Station Jungfraujoch on a regular basis. The main research question in this study is to get an insight in the annual INP cycle and to refer to differences in INP number concentrations when sampling in convectively lifted boundary layer air, compared to the usual free tropospheric conditions that prevail at the observational site. HINC is also used for laboraotry based investigations of soot aerosols and their impacts on ice nucleation.

Contact: Guangyu Li or Baptiste Testa

Working principle:

HINC consists of two horizontal plates which can be cooled to temperatures relevant for ice and mixed-phase clouds. As the plates are covered with wet filter papers, a supersaturation with respect to water and ice is established through a temperature difference of the upper and lower plates. Two freezing modes can be investigated in HINC: Deposition freezing with RH_ice > 100% but RH_water < 100% and condensation freezing with both RH_ice and RH_water > 100%.

References:
Kanji, Z. A. and J. P. D. Abbatt. The University of Toronto Continuous Flow Diffusion Chamber (UT-CFDC): A Simple Design for Ice Nucleation Studies (2009). Aerosol Science and Technology, 43: 730-738. external page DOI: 10.1080/02786820902889861

Lacher, L., Lohmann, U., Boose, Y., Zipori, A., Herrmann, E., Bukowiecki, N., Steinbacher, M. and Z. A. Kanji. The Horizontal Ice Nucleation Chamber (HINC): INP measurements at conditions relevant for mixed-phase clouds at the High Altitude Research Station Jungfraujoch (2017). Atmospheric Chemistry and Physics, 17, 15199 - 15224. (external page DOI: 10.5194/acp-17-15199-2017)

Mahrt F., C. Marcolli, R. O. David, P. Grönquist, E. G. Bathazy Meier, U. Lohmann and Z. A. Kanji. Ice nucleation abilities of soot particles determined with the Horizontal Ice Nucleation Chamber (2018). Atmospheric Chemistry and Physics, 18, 13363 - 13392, external page DOI:10.5194/acp-2018-557