title: Latitudinal and Seasonal Distribution of Particulate MSA over the Atlantic using a Validated Quantification Method with HR-ToF-AMS.
abstract: 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, R2= 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:nssSO4) 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 μg m-3) than in autumn (0.01 μg m-3). The investigation of MSA:nssSO4suggests a ubiquitous and significant influence of anthropogenic sources on aerosols in the marine boundary layer.
authors.affiliation: Leibniz Institute for Tropospheric Research , Leipzig, Sachsen, 04318, Germany.|Institute for Environmental and Climate Research, Jinan University , Guangzhou, Guangdong 511443, China.
authors.forename: Shan
authors.identifier: 0000-0001-5575-4510
authors.initials: S
authors.lastname: Huang
authors.affiliation: Leibniz Institute for Tropospheric Research , Leipzig, Sachsen, 04318, Germany.
authors.forename: Laurent
authors.initials: L
authors.lastname: Poulain
authors.affiliation: Leibniz Institute for Tropospheric Research , Leipzig, Sachsen, 04318, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: van Pinxteren
authors.affiliation: Leibniz Institute for Tropospheric Research , Leipzig, Sachsen, 04318, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: van Pinxteren
authors.affiliation: College of Environmental Sciences and Engineering, Peking University , Beijing, 100871, China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Leibniz Institute for Tropospheric Research , Leipzig, Sachsen, 04318, Germany.
authors.forename: Hartmut
authors.initials: H
authors.lastname: Herrmann
authors.affiliation: Leibniz Institute for Tropospheric Research , Leipzig, Sachsen, 04318, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Wiedensohler
mesh_terms: D000336:Aerosols; D000393:Air Pollutants; D002980:Climate; D013058:Mass Spectrometry; D013431:Sulfates
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D013431:Sulfates