Aerosol-Ice Formation Closure Study Applying Ambient Aerosol Particles
EMSL Project ID
50738
Abstract
Atmospheric ice nucleation represents one of the least understood atmospheric processes, hampering prediction of cloud processes and climate. Whereas the aerosol community has widely conducted aerosol-cloud condensation nuclei studies to evaluate the physical models and parameterizations that cloud-resolving and climate models rely on to perform reliable simulations of the Earth system and energy budget, very few closure studies related to ice nucleating particles (INPs) have been performed. A pilot study at the Atmospheric Radiation Measurement User Facility at Southern Great Plains will be conducted to test a field observational approach for an aerosol-ice formation closure study based on using size-resolved ambient aerosol composition measurements. We aim to measure ambient immersion freezing INPs and to simultaneously quantify the leading measurable aspects of the aerosol population relevant to the ice crystal formation rates by immersion freezing. A novel aspect of this field campaign is to include particle sizes and composition up to 16 micrometer since supermicron particles can contribute significantly to the overall INP concentration. The measured aerosol population data, in turn, will serve as input for prediction of INP numbers using various state-of-the-art ice nucleation parameterizations and models, whose agreement with the online and offline INP measurements can be evaluated within relevant uncertainties.
Ambient aerosol particles collected on substrates for spectro-microscopic and chemical imaging analyses and ice nucleation experiments will play a crucial role in achieving aerosol-ice formation closure. Online aerosol mass spectrometer analysis is limited to the non-refractory particle constituents and to a maximum particle size of about 2-3 micrometer. EMSL/PNNL provides unique micro-spectroscopic single particle analytical techniques and high-resolution mass spectrometric techniques to examine the physicochemical characteristics of aerosols and INPs in the nm-to-um size range and resolve associated molecular signatures in the particulate phase. This analytical capability will be vital for achieving closure and will allow us to identify ice nucleation parameterizations that produce the most robust predictions of INP numbers and thus are best suited to be included in cloud and climate models.
The objectives of the proposed aerosol-ice formation closure study are directly relevant to the missions of BER and the EMSL User Facility by improving our predictive understanding of Earth's complex environmental systems. Fundamental science on the processes governing clouds, aerosols, and precipitation interactions will be acquired that will enable sound scientific developments in a complex field of Earth system-relevant atmospheric process and modeling research. The goals of this research are in direct response to the EMSL Science Theme "Environmental Sciences Area" that focuses on determination of the physical and chemical properties that make some aerosols more efficient INPs than others and investigate the role of primary biological particles as INPs. The unique combination of ice nucleation experiments with the nanoscale physicochemical characterization of aerosol particles complemented by other field measurements will advance our fundamental understanding and predictive capability of the physicochemical characteristics of aerosol particles that initiate ice nucleation. Relevant EMSL instruments to examine the microstructure and chemical characteristics of ambient particles and INPs include FIB/SEM-EDX, TEM, LTQ-Orbitrap MS with nano-DESI, and Nano-SIMS.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2019-10-01
End Date
2021-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
P. A. Alpert, K. R. Barry, T. A. Brubaker, S. China, J. M. Creamean, P. J. DeMott, A. M. Fridlind, T. C. J. Hill, N. Hiranuma, L. G. Jahl, K. A., L. Jankowski, D. A. Knopf, A. Laskin, N. N. Lata, E. J. T. Levin, J. Li, X. Liu, Y. Lu, R. C. Moffet, L. W. Monroe, K. A. Moore, N. Riemer, F. A. Rivera-Adorno, K. A. Sauceda, Y. Shi, R. C. Sullivan, J. M. Tomlin, H. S. K. Vepuri, P. Wang, M. West. 2021. "Aerosol–Ice Formation Closure: A Southern Great Plains Field Campaign." Bulletin of the American Meteorological Society:1-50. https://doi.org/10.1175/BAMS-D-20-0151.1