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Title: Direct Online Mass Spectrometry Measurements of Ice Nucleating Particles at a California Coastal Site
Abstract

The formation of ice in clouds can strongly impact cloud properties and precipitation processes during storms, including atmospheric rivers. Sea spray aerosol (SSA) particles are relatively inefficient as ice nucleating particles (INPs) compared to mineral dust. However, due to the vast coverage of the Earth's surface by the oceans, a number of recent studies have focused on identifying sources of marine INPs, particularly in regions lacking a strong influence from dust. This study describes the integration, validation, and application of a system coupling a continuous flow diffusion chamber with a single particle mass spectrometer using a pumped counterflow virtual impactor to remove nonnucleated particles and selectively measure the composition of INPs with a detection efficiency of 3.10×10−4. In situ measurements of immersion freezing INP composition were made at a coastal site in California using the integrated system. Mineral dust particles were the most abundant ice crystal residual type during the sampling period and found to be ice active despite having undergone atmospheric processing. SSA were more abundant in ambient measurements but represented only a minor fraction of the ice crystal residual population at −31 °C. Notably, the SSA particles that activated were enriched with organic nitrogen species that were likely transferred from the ocean. Calculations of ice nucleation active site densities were within good agreement with previous studies of mineral dust and SSA.

 
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Award ID(s):
1801971 1451347
NSF-PAR ID:
10455826
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  
Publisher / Repository:
DOI PREFIX: 10.1029
Date Published:
Journal Name:
Journal of Geophysical Research: Atmospheres
Volume:
124
Issue:
22
ISSN:
2169-897X
Page Range / eLocation ID:
p. 12157-12172
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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