Molecular markers for fungal spores and biogenic SOA over the Antarctic Peninsula: Field measurements and modeling results

• Biogenic organic aerosols are important components of atmospheric organic aerosols and play vital roles in atmospheric chemistry, global climate, and biogeochemical cycles of carbon. However, studies on biogenic organic aerosols in the vast regions of the Southern Ocean and over the coastal waters of the Antarctic, especially Antarctic Peninsula, are still extremely limited. To understand the concentrations, molecular composition and seasonality of biogenic organic aerosols in Antarctica, atmospheric aerosols were collected at the Palmer Station on the west Antarctic Peninsula experiencing dramatic climate warming. Molecular marker compounds of fungal spores and secondary organic aerosols formed from the photooxidation of isoprene and monoterpene were analyzed using gas chromatography/mass spectrometry. Concentrations of sugar alcohols and biogenic SOA tracers both presented seasonal patterns with higher average concentrations in summer (90.7 and 122 pg m−3) than in winter (8.88 and 57.2 pg m−3). Sugar alcohols and biogenic SOA tracers were predominated by mannitol and isoprene oxidation products. Relative contributions of fungal-spore organic carbon (OC), isoprene-derived secondary OC (SOC) and monoterpene-derived SOC estimated with tracer-based methods were 26.2%, 55.6% and 18.2%, respectively. The observed seasonality of total biogenic SOA and some molecular species at the Antarctic Peninsula was further supported by the results from the global model CESM/IMPACT. Model results also suggest higher biogenic SOA in East Antarctica than that in West Antarctica, which is attributed to the influence of vertical atmospheric circulation. Our results of air-mass trajectory indicate the potential influence of marine emissions on the biogenic organic aerosols over the Antarctic Peninsula. © 2020 Elsevier B.V.

Ämnesord

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

Antarctica

Fungal spore

Isoprene SOA

Primary organic aerosols

Secondary organic aerosols

Atmospheric chemistry

Biogeochemistry

Fungi

Gas chromatography

Isoprene

Monoterpenes

Organic carbon

Photooxidation

Polyols

Sugar industry

Tracers

Air mass trajectories

Atmospheric circulation

Average concentration

Biogeochemical cycle

Gas chromatography/Mass spectrometry

Molecular compositions

Relative contribution

Atmospheric aerosols

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