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Atmospheric Ice Nucleation

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Aerosol-cloud interactions, including the ice nucleation of supercooled liquid water droplets caused by ice nucleating particles (INPs), are a source of  uncertainty in predicting future climate. Because of INP’s spatial and temporal heterogeneity in source, number, and composition, predicting their concentration and distribution is a challenge. In our group, we developed new instrumentation (Freezing Ice Nucleation Counter, FINC) and methodologies (high speed camera, tensiometer) to study the mechanisms of freezing in mixed-phase clouds. We are in why and how organic aerosols nucleate ice to reduce the uncertainty in projected global warming estimates.

Top-Down Approach

Spatial and temporal variability in the ice-nucleating ability of alpine snowmelt and extension to frozen cloud fraction.


Brennan, K. P., David, R. O., Borduas-Dedekind, N.* (2020) Atmos. Chem. Phys., 20: 163-180

Photomineralization mechanism changes the ability of dissolved organic matter to activate cloud droplets and to nucleate ice crystals.

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Borduas-Dedekind, N.*, Ossola, R., David, R.O., Boynton, L.S., Weichlinger, V., Kanji, Z. A.*, McNeill, K. (2019) Atmos. Chem. Phys., 19: 12397-12412

Tracking the Photomineralization Mechanism in Irradiated Lab-Generated and Field-Collected Brown Carbon Samples and Its Effect on Cloud Condensation Nuclei Abilities.

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Müller, S., Giorio, C., Borduas-Dedekind, N.  (2023) ACS Environmental Au, 3 (3): 164-178

Ice Nucleating Ability of Soil

Bottom-Up Approach

Development of the drop Freezing Ice Nuclei Counter (FINC), intercomparison of droplet freezing techniques, and use of soluble lignin as an atmospheric ice nucleation standard.

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Miller, A. J., Brennan, K. P., Mignani, C., Wieder, J., David, R. O., Borduas-Dedekind, N.* (2021) Atmos. Meas. Techn.,14: 3131-3151

Lignin's ability to nucleate ice via immersion freezing and its stability towards physicochemical treatments and atmospheric processing.

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Bogler, S., Borduas-Dedekind, N.* (2020) Atmos. Chem. Phys., 20: 14509-14522

Organic Nanoparticle Formation

High Speed Images of Freezing

Team Ice 


Paul Bieber


William Bae


Emily Chiao

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