Improving Representation of Ice Particle Formation in Cloud Models

A commercially available ice nucleation instrument helps achieve better understanding of atmospheric ice particle formation.

The Science

A new instrument, the spectrometer for ice nuclei (SPIN), enables investigation of the ice nucleation properties of aerosol particles at mixed-phase and cirrus cloud conditions.

The Impact

Ice nucleation measurements at higher temporal and spatial resolution are missing. These measurements are necessary to improve and develop ice nucleation parameterizations used in climate models. Such high-density coverage will yield better understanding of atmospheric ice formation, which produces large uncertainties in simulating Earth’s climate and hydrological cycle.


The nature of atmospheric aerosol particles responsible for nucleating ice are not understood. This critical gap induces large uncertainties in representing ice particle formation processes in cloud models. The new commercially available SPIN chamber improves the coverage of ice nucleation measurements. SPIN is based on the continuous flow diffusion chamber (CFDC) style ice nucleation chamber, where aerosol particles are exposed to defined temperature and supersaturation conditions and ice nucleated particles are grown to be counted as ice crystals. SPIN also consists of an evaporation section to evaporate  super cooled droplets and an advanced particle counter to distinguish liquid and ice phases. SPIN is well characterized using laboratory standards and is commercially available.

Principal Investigator(s)

Gourihar Kulkarni
Pacific Northwest National Laboratory


This work was supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs.


Garimella, S., T. B. Kristensen, K. Ignatius, A. Welti, J. Voightlander, G. Kulkarni, F. Sagan, G. L. Kok, J. Dorsey, L. Nichman, D. A. Rothenberg, M. Rosch, A. C. R. Kurchgassner, R. Ladkin, H. Wex, T. W. Wilson, L. A. Ladino, J. P. D. Abbatt, O. Stetzer, U. Lohmann, F. Stratmann, and D. J. Cziczo. 2016. “The SPectrometer for Ice Nuclei (SPIN): An Instrument to Investigate Ice Nucleation,” Atmospheric Measurement Techniques 9(7), 2781-95. DOI:10.5194/amt-9-2781-2016.