气候变化领域集成服务门户(CCPortal): Quantifying bioaerosol concentrations in dust clouds through online UV-LIF and mass spectrometry measurements at the Cape Verde Atmospheric Observatory

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DOI	10.5194/acp-20-14473-2020
	Quantifying bioaerosol concentrations in dust clouds through online UV-LIF and mass spectrometry measurements at the Cape Verde Atmospheric Observatory
	Morrison D.; Crawford I.; Marsden N.; Flynn M.; Read K.; Neves L.; Foot V.; Kaye P.; Stanley W.; Coe H.; Topping D.; Gallagher M.
发表日期	2020
ISSN	1680-7316
起始页码	14473
结束页码	14490
卷号	20 期号:22
英文摘要	Observations of the long-range transport of biological particles in the tropics via dust vectors are now seen as fundamental to the understanding of many global atmosphere–ocean biogeochemical cycles, changes in air quality, human health, ecosystem impacts, and climate. However, there is a lack of long-term measurements quantifying their presence in such conditions. Here, we present annual observations of bioaerosol concentrations based on online ultraviolet laser-induced fluorescence (UV-LIF) spectrometry from the World Meteorological Organization – Global Atmospheric Watch (WMO-GAW) Cape Verde Atmospheric Observatory on São Vicente. We observe the expected strong seasonal changes in absolute concentrations of bioaerosols with significant enhancements during winter due to the strong island inflow of air mass, originating from the African continent. Monthly median bioaerosol concentrations as high as 45 L−1 were found with 95th percentile values exceeding 130 L−1 during strong dust events. However, in contrast, the relative fraction of bioaerosol numbers compared to total dust number concentration shows little seasonal variation. Mean bioaerosol contributions accounted for 0.4 ± 0.2 % of total coarse aerosol concentrations, only rarely exceeding 1 % during particularly strong events under appropriate conditions. Although enhancements in the median bioaerosol fraction do occur in winter, they also occur at other times of the year, likely due to the enhanced Aeolian activity driving dust events at this time from different sources. We hypothesise that this indicates the relative contribution of bioaerosol material in dust transported across the tropical Atlantic throughout the year is relatively uniform, comprised mainly of mixtures of dust and bacteria and/or bacterial fragments. We argue that this hypothesis is supported from analysis of measurements also at Cabo Verde just prior to the long-term monitoring experiment where UV-LIF single particle measurements were compared with laser ablation aerosol particle time-of-flight mass spectrometer (LAAP-ToF) measurements. These clearly show a very high correlation between particles with mixed biosilicate mass spectral signatures and UV-LIF biofluorescent signatures suggesting the bioaerosol concentrations are dominated by these mixtures. These observations should assist with constraining bioaerosol concentrations for tropical global climate model (GCM) simulations. Note that here we use the term “bioaerosol” to include mixtures of dust and bacterial material. © Author(s) 2020.
英文关键词	aerosol; climate modeling; computer simulation; concentration (composition); dust; mass spectrometry; seasonal variation; ultraviolet radiation; Cape Verde [Macaronesia]; Bacteria (microorganisms)
语种	英语
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/168940
作者单位	Department of Earth and Environmental Science, University of Manchester, Brunswick StManchester, United Kingdom; Wolfson Atmospheric Chemistry Laboratory, University of York, York, United Kingdom; Science and Technology Research Institute, University of Hertfordshire, Hatfield, United Kingdom; Defence Science and Technology Laboratory, Salisbury, United Kingdom
推荐引用方式 GB/T 7714	Morrison D.,Crawford I.,Marsden N.,et al. Quantifying bioaerosol concentrations in dust clouds through online UV-LIF and mass spectrometry measurements at the Cape Verde Atmospheric Observatory[J],2020,20(22).
APA	Morrison D..,Crawford I..,Marsden N..,Flynn M..,Read K..,...&Gallagher M..(2020).Quantifying bioaerosol concentrations in dust clouds through online UV-LIF and mass spectrometry measurements at the Cape Verde Atmospheric Observatory.Atmospheric Chemistry and Physics,20(22).
MLA	Morrison D.,et al."Quantifying bioaerosol concentrations in dust clouds through online UV-LIF and mass spectrometry measurements at the Cape Verde Atmospheric Observatory".Atmospheric Chemistry and Physics 20.22(2020).