Si, M, Irish, VE, Mason, RH et al. (10 more authors) (2018) Ice-nucleating ability of aerosol particles and possible sources at three coastal marine sites. Atmospheric Chemistry and Physics, 18 (21). pp. 15669-15685. ISSN 1680-7316
Abstract
Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea) and one in the Arctic (Lancaster Sound). For Amphitrite Point, 23 sets of samples were analyzed, and for Labrador Sea and Lancaster Sound, one set of samples was analyzed for each location. At all three sites, the ice-nucleating ability on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the particle size. For example, at diameters of around 0.2µm, approximately 1 in 106 particles acted as an INP at −25°C, while at diameters of around 8µm, approximately 1 in 10 particles acted as an INP at −25°C. The ice-nucleating ability on a per surface-area basis (expressed as the surface active site density, ns) was also dependent on the particle size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosols, suggesting that sea spray aerosols were not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25°C, but under-predicted INP concentrations at −15°C, suggesting that the model is missing a source of INPs active at a freezing temperature of −15°C.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2018, Author(s). This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
Dates: |
|
Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number EU - European Union 648661 |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Nov 2018 14:43 |
Last Modified: | 02 Nov 2018 14:43 |
Status: | Published |
Publisher: | Copernicus Publications |
Identification Number: | 10.5194/acp-18-15669-2018 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:138107 |