Characterization of a New Portable Ice Nucleation Experiment chamber (PINE) and First Field Deployment in the Southern Great Plains

We present our first laboratory calibration and field results of a newly developed commercial ice nucleation chamber, the so-called PINE. The PINE instrument is developed based on the design of the AIDA cloud chamber (Möhler et al., 2003) to advance online atmospheric ice nucleation research. A unique aspect of the PINE chamber includes its plug-and-play feature (so it runs on a standard power outlet), autonomous cryo-cooler-based temperature-ramping operation, capability of quantifying INPs in different IN modes (e.g., immersion freezing and deposition mode at >-60 °C), small particle loss through the system (~5% for <5 mm diameter particles), and sensitive optical particle detection of INP concentration (≤0.1 L^-1 at T > -15 °C), promising stand-alone operation at remote locations. To date, the PINE chamber has been calibrated using test aerosol particles with known properties (e.g., illite NX). Briefly, test particles were exposed to ice supersaturation conditions, where a mixture of droplets and ice crystals were formed during the ‘expansion’ experiment. A comparison of our calibration test results to other techniques will be presented. Further, the PINE instrument has been tested in field campaigns in the Southern Great Plains. With a turnover time of ~6 minutes, PINE ran continuously and scanned at different temperature intervals to assess different INP episodes. We made sure to assess at least a few degrees of common temperature interval in a series of scan. Our first field results will be shown. Our results suggest that using this autonomous instrument may be critical to minimize error sources in high-temperature and supermicron INP research.

Acknowledgement: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (DE-SC0018979) – work packages 1-2 of Implications of Aerosol Physicochemical Properties Including Ice Nucleation at ARM Mega Sites for Improved Understanding of Microphysical Atmospheric Cloud Processes.

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