Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 17, 14291-14307, 2017
https://doi.org/10.5194/acp-17-14291-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
01 Dec 2017
Real-time detection of airborne fluorescent bioparticles in Antarctica
Ian Crawford1, Martin W. Gallagher1, Keith N. Bower1, Thomas W. Choularton1, Michael J. Flynn1, Simon Ruske1, Constantino Listowski2,a, Neil Brough2, Thomas Lachlan-Cope2, Zoë L. Fleming3, Virginia E. Foot4, and Warren R. Stanley5 1Centre for Atmospheric Science, SEES, University of Manchester, Manchester, UK
2British Antarctic Survey, NERC, High Cross, Madingley Rd., Cambridge, UK
3University of Leicester, Department of Chemistry, Leicester, UK
4Defence Science & Technology Laboratory, Porton Down, Salisbury, Wilts, UK
5Science and Technology Research Institute, University of Hertfordshire, Hatfield, Hertfordshire, UK
anow at: LATMOS/IPSL, UVSQ Université Paris-Saclay, UPMC Univ. Paris 06, CNRS, Guyancourt, France
Abstract. We demonstrate, for the first time, continuous real-time observations of airborne bio-fluorescent aerosols recorded at the British Antarctic Survey's Halley VI Research Station, located on the Brunt Ice Shelf close to the Weddell Sea coast (lat 75°34′59′′ S, long 26°10′0′′ W) during Antarctic summer, 2015. As part of the NERC MAC (Microphysics of Antarctic Clouds) aircraft aerosol cloud interaction project, observations with a real-time ultraviolet-light-induced fluorescence (UV-LIF) spectrometer were conducted to quantify airborne biological containing particle concentrations along with dust particles as a function of wind speed and direction over a 3-week period.

Significant, intermittent enhancements of both non- and bio-fluorescent particles were observed to varying degrees in very specific wind directions and during strong wind events. Analysis of the particle UV-induced emission spectra, particle sizes and shapes recorded during these events suggest the majority of particles were likely a subset of dust with weak fluorescence emission responses. A minor fraction, however, were likely primary biological particles that were very strongly fluorescent, with a subset identified as likely being pollen based on comparison with laboratory data obtained using the same instrument.

A strong correlation of bio-fluorescent particles with wind speed was observed in some, but not all, periods. Interestingly, the fraction of fluorescent particles to total particle concentration also increased significantly with wind speed during these events. The enhancement in concentrations of these particles could be interpreted as due to resuspension from the local ice surface but more likely due to emissions from distal sources within Antarctica as well as intercontinental transport. Likely distal sources identified by back trajectory analyses and dispersion modelling were the coastal ice margin zones in Halley Bay consisting of bird colonies with likely associated high bacterial activity together with contributions from exposed ice margin bacterial colonies but also long-range transport from the southern coasts of Argentina and Chile. Dispersion modelling also demonstrated emissions from shipping lanes, and therefore marine anthropogenic sources cannot be ruled out. Average total concentrations of total fluorescent aerosols were found to be 1.9 ± 2.6 L−1 over a 3-week period crossing over from November into December, but peak concentrations during intermittent enhancement events could be up to several tens per litre. While this short pilot study is not intended to be generally representative of Antarctic aerosol, it demonstrates the usefulness of the UV-LIF measurement technique for quantification of airborne bioaerosol concentrations and to understand their dispersion. The potential importance for microbial colonisation of Antarctica is highlighted.


Citation: Crawford, I., Gallagher, M. W., Bower, K. N., Choularton, T. W., Flynn, M. J., Ruske, S., Listowski, C., Brough, N., Lachlan-Cope, T., Fleming, Z. L., Foot, V. E., and Stanley, W. R.: Real-time detection of airborne fluorescent bioparticles in Antarctica, Atmos. Chem. Phys., 17, 14291-14307, https://doi.org/10.5194/acp-17-14291-2017, 2017.
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Short summary
We present the first real-time detection of bioparticles on the Antarctic continent using a novel UV-LIF technique. The high time resolution of the technique allowed us to examine the relationships between bioparticle concentrations and airmass history and local winds, which would not have been possible with conventional high-volume filter sampling techniques. We also show evidence of episodic long-range transport of pollen from coastal South America to the continent.
We present the first real-time detection of bioparticles on the Antarctic continent using a...
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