New instrument to study ice crystal residuals



Kulkarni, Gourihar - Pacific Northwest National Laboratory

Area of research:

Aerosol Properties

Journal Reference:

Hiranuma N, O Möhler, G Kulkarni, M Schnaiter, S vogt, P Vochezer, E Järvinen, R Wagner, DM Bell, J Wilson, A Zelenyuk, and DJ Cziczo. 2016. "Development and characterization of an ice-selecting pumped counterflow virtual impactor (IS-PCVI) to study ice crystal residuals." Atmospheric Measurement Techniques, 9(8), 10.5194/amt-9-3817-2016.


A new instrument that allows separation of cloud elements to examine the physical and chemical properties of ice crystals is necessary to further our understanding of aerosol-cloud interactions.


Current ice nucleation parameterizations do not consider the specific aerosol properties (composition, morphology, mixing state, etc.), and therefore fail to simulate ice formation in the atmosphere within a model. These formulations can be improved by investigating only aerosol properties that formed ice crystals, which can be accomplished using the new pumped counterflow virtual impactor (PCVI) instrument.


The ice-forming process in the atmosphere is very selective. Ice-nucleating properties of aerosol particles are poorly understood, and currently very little is known about the special characteristics that nucleate ice. Scientists, including Department of Energy researchers at Pacific Northwest National Laboratory, found the new PCVI instrument allows separation of large ice crystals, without shattering and breakup artifacts, and extraction of the residuals for further analysis. They tested the new instrument under a wide range of temperature and humidity conditions connected to the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) cloud simulation chamber at the Karlsruhe Institute of Technology in Germany, and deployed it at the Fifth International Ice Nucleation workshop. They performed chemical composition analysis of residuals to further characterize the PCVI instrument.