Submicron NE Atlantic marine aerosol chemical composition and abundance: Seasonal trends and air mass categorization

Abstract

Three years of continuous Aerosol Mass Spectrometry measurements at the Mace Head GlobalAtmosphere Watch research station revealed seasonal patterns in the chemical composition of submicron NE Atlantic marine aerosol as well as distinct chemical signatures associated with marine air masses of different origin (i.e., polar, Arctic, or tropical). Concentrations of secondary inorganic aerosol species and both primary and secondary organic compounds were closely related to oceanic biological activity and ranged from low median mass concentrations during winter to high median values during summer as follows: 0.025-0.9 μg m ). Maritime polar air masses typically featured the highest concentrations of sea salt and marine organics, particularly enhanced under primary organic plumes during periods of high biological activity. MSA and nss-sulfate were more prominent in tropical air masses. The oxidation of organic matter increased with increasing ozone concentration and wintertime (low biological activity) organic matter displayed a different fragmentation pattern from that of summertime organic compounds.

Aerosol measurements during COPE: composition, size, and sources of CCN and INPs at the interface between marine and terrestrial influences

“…Around 60-70 % of submicron aerosol mass was sulfate, in the form of a mixture of sulfuric acid and ammonium bisulfate as there was insufficient ammonium for full neutralisation. This is in agreement with measurements of North Atlantic aerosol made by Ovadnevaite et al (2014).…”

What do we learn from long-term cloud condensation nuclei number concentration, particle number size distribution, and chemical composition measurements at regionally representative observatories?

“…At the coastal sites in the Mediterranean (FIK) and Atlantic (MHD), 30 the non-refractory submicron aerosol particle mass is driven by inorganic components, predominantly sulfate. However, increased organic particle mass is observed during the biomass burning season at FIK (Bougiatioti et al, 2016), when κ reaches a minimum, and in springtime at MHD, as has been observed previously (Ovadnevaite et al, 2014 generally high owing to the influence of sea salt, but at the same time is also very variable owing to the mixed influences of marine organic aerosol and anthropogenic air pollution. Fig.…”

“…Low number concentrations are also found at the coastal site MHD, which for certain periods reflects the clean marine conditions over the Atlantic Ocean (Ovadnevaite et al, 2014). The coastal environments of FIK in the Mediterranean and NOT in the Pacific Ocean exhibit generally higher concentrations due to particular pollution influences which for example include long-range transport of NE European pollution and biomass burning plumes (Bougiatioti et al, 2016) and long-range 5 transport of East Asian pollutions plumes (Iwamoto et al, 2016), respectively.…”

“…The high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) operated at Mace Head has been described by DeCarlo et al (2006) in general and in particular for Mace Head by Ovadnevaite et al (2014). The aerosol chemical 25 speciation monitor (ACSM), deployed at all other stations, has been introduced by Ng et al (2011) and the first official ACTRIS intercomparison is described in Crenn et al (2015).…”

Missing SO<sub>2</sub> oxidant in the coastal atmosphere? – observations from high-resolution measurements of OH and atmospheric sulfur compounds

“…Corresponding seasonal cycles of aerosol MSA and non-sea-salt sulfate (nss-SO 4 ) have been measured at Mace Head using high-resolution timeof-flight aerosol mass spectrometry (HR-TOF-MS). Both aerosol compounds and their concentration ratio show a clear seasonal maximum in summer (Ovadnevaite et al, 2014). The mean seasonal cycle of peak MSA(g) mixing ratios recorded during the same daily time slot as for H 2 SO 4 and summarized as monthly means is also shown in Fig.…”