Abstract. Size-segregated particulate air samples were collected during the
austral summer of 2016–2017 at Palmer Station on Anvers Island, western Antarctic Peninsula,
to characterize trace elements in aerosols. Trace
elements in aerosol samples – including Al, P, Ca, Ti, V, Mn, Ni, Cu, Zn, Ce,
and Pb – were determined by total digestion and a sector field inductively
coupled plasma mass spectrometer (SF-ICP-MS). The crustal enrichment factors
(EFcrust) and k-means clustering results of particle-size distributions
show that these elements are derived primarily from three sources: (1) regional crustal emissions, including possible resuspension of soils
containing biogenic P, (2) long-range transport, and (3) sea salt. Elements
derived from crustal sources (Al, P, Ti, V, Mn, Ce) with
EFcrust<10 were dominated by the coarse-mode particles
(>1.8 µm) and peaked around 4.4 µm in diameter,
reflecting the regional contributions. Non-crustal elements (Ca, Ni, Cu, Zn,
Pb) showed EFcrust>10. Aerosol Pb was primarily dominated
by fine-mode particles, peaking at 0.14–0.25 µm, and likely was
impacted by air masses from southern South America based on air mass back
trajectories. However, Ni, Cu, and Zn were not detectable in most size
fractions and did not present clear size patterns. Sea-salt elements (Ca,
Na+, K+) showed a single-mode distribution and peaked at 2.5–4.4 µm. The estimated dry deposition fluxes of mineral dust for the
austral summer, based on the particle-size distributions of Al measured at
Palmer Station, ranged from 0.65 to 28 mg m−2 yr−1 with a mean of
5.5±5.0 mg m−2 yr−1. The estimated dry deposition fluxes
of the target trace elements in this study were lower than most fluxes
reported previously for coastal Antarctica and suggest that atmospheric
input of trace elements through dry deposition processes may play a minor
role in determining trace element concentrations in surface seawater over
the continental shelf of the western Antarctic Peninsula.
Estimation of Emission Sources of Trace Elements in an Atmospheric Aerosol by Particle Size Distributions