Real-time detection of airborne fluorescent bioparticles in Antarctica
Real-time detection of airborne fluorescent bioparticles in Antarctica
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DOI：
10.5194/acp-17-14291-2017
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发表时间：
2017-12-01
影响因子：
6.3
通讯作者：
Stanley, Warren R.
中科院分区：
文献类型：
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作者：
Crawford, Ian;Gallagher, Martin W.;Stanley, Warren R.
我们首次展示了2015年夏季南极期间英国南极调查局哈雷六号研究站记录的空中生物荧光气溶胶的连续实时观测，该研究站位于布伦特冰架上，靠近韦德尔海海岸(北纬75°34‘59“S，西经26°10’0‘)。作为NERC MAC(南极云微物理)飞机气溶胶云相互作用项目的一部分，利用实时紫外光诱导荧光(UV-LIF)光谱仪进行了3周的观测，以量化空气中含有生物粒子的浓度以及随风速和风向变化的尘埃粒子。在非常特定的风向和大风事件期间，观察到非荧光粒子和生物荧光粒子都有不同程度的间歇性增强。对这些事件期间记录的粒子紫外线诱导发射光谱、粒子大小和形状的分析表明，大多数粒子很可能是荧光发射响应较弱的尘埃的子集。然而，有一小部分很可能是初级生物颗粒，它们的荧光非常强，根据与使用同一仪器获得的实验室数据的比较，确定了一小部分可能是花粉。在某些时期，但不是所有时期，生物荧光颗粒与风速有很强的相关性。有趣的是，在这些事件中，荧光颗粒占总颗粒浓度的比例也随着风速的增加而显著增加。这些颗粒浓度的增加可以解释为由于当地冰面的再悬浮，但更有可能是由于南极洲内远端来源的排放以及洲际运输。回溯轨迹分析和扩散模型确定的可能远端来源是哈雷湾的沿海冰缘地带，其中包括可能相关的高细菌活动的鸟类群体，以及暴露的冰缘细菌群体的贡献，但也包括来自阿根廷和智利南部海岸的长距离运输。扩散模型还表明，来自航道的排放，因此不能排除海洋人为来源。在11月至12月的3个星期内，总荧光气溶胶的平均总浓度为1.9+/-2.6 L-1，但间歇性增强活动期间的峰值浓度可能高达每升数十。虽然这项简短的试验性研究并不是为了全面代表南极气溶胶，但它证明了紫外线-激光诱导荧光测量技术在量化空气中生物气溶胶浓度和了解其分散情况方面的作用。强调了南极洲微生物殖民的潜在重要性。
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 degrees 34'59 '' S, long 26 degrees 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.