摘要:
Methanesulfonic acid (MSA) has been widely used as a proxy for marine biogenic sources, but it is still a challenge to provide an accurate MSA mass concentration with high time resolution. This study offers an improved MSA quantification method using high resolution time of-flight aerosol mass spectrometer (HR-ToF-AMS). Particularly, the method was validated based on an excellent agreement with parallel offline measurements (slope = 0.88, R-2 = 0.89). This comparison is much better than those using previously reported methods, resulting in underestimations of 31-54% of MSA concentration. With this new method, MSA mass concentrations were obtained during 4 North/South Atlantic cruises in spring and autumn of 2011 and 2012. The seasonal and spatial variation of the particulate MSA mass concentration as well as the MSA to non-sea-salt sulfate ratio (MSA:nssSO(4)) over the North/South Atlantic Ocean were determined for the first time. Seasonal variation of the MSA mass concentration was observed, with higher values in spring (0.03 mu g m(-3)) than in autumn (0.01 mu g m(-3)). The investigation of MSA:nssSO(4) suggests a ubiquitous and significant influence of anthropogenic sources on aerosols in the marine boundary layer.附注:
ISI Document Delivery No.: EG8ZRTimes Cited: 5Cited Reference Count: 56Huang, Shan Poulain, Laurent van Pinxteren, Dominik van Pinxteren, Manuela Wu, Zhijun Herrmann, Hartmut Wiedensohler, AlfredHerrmann, Hartmut/C-2486-2009; Wu, Zhijun/A-7041-2012Herrmann, Hartmut/0000-0001-7044-2101; Huang, Shan/0000-0001-5575-4510Gottfried Wilhelm Leibniz Association (OCEANET project); [AWI_ANT27/4]; [AWI_ANT28/1]; [AWI_ANT28/5]; [AWIANT29/1]We specially thank all crews and scientists on board R/V Polarstern. We thank Alfred Wegener Institute (AWI) and Germany Weather Service (DWD) for sharing data of cruises, specifically on navigation, oceanography, meteorology, and air mass back trajectories. We thank all the support through the following projects and research programs: (1) the Gottfried Wilhelm Leibniz Association (OCEANET project in the framework of PAKT), and (2) Polarstern expeditions AWI_ANT27/4, AWI_ANT28/1, AWI_ANT28/5, AWIANT29/1.524Amer chemical socWashington1520-5851