Mass-particle size distributions of atmospheric dust and the dry deposition of dust to the remote ocean

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.

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Interactive comment on “Concentrations, Particle-Size Distributions, and Dry Deposition Fluxes of Aerosol Trace Elements over the Antarctic Peninsula” by Songyun Fan et al.

10.5194/acp-2020-651-rc2 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Particle Size ◽

Trace Elements ◽

Antarctic Peninsula ◽

Dry Deposition ◽

Size Distributions ◽

Particle Size Distributions ◽

Deposition Fluxes ◽

The Antarctic

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Modelling and measurements of urban aerosol processes on the neighborhood scale in Rotterdam, Oslo and Helsinki

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-35157-2015 ◽

2015 ◽

Vol 15 (23) ◽

pp. 35157-35200

Author(s):

M. Karl ◽

J. Kukkonen ◽

M. P. Keuken ◽

S. Lützenkirchen ◽

L. Pirjola ◽

...

Keyword(s):

Particle Size ◽

Gas Phase ◽

Dry Deposition ◽

Particle Number ◽

Measured Data ◽

Sensitivity Analyses ◽

Size Distributions ◽

Particle Size Distributions ◽

Coagulation Of Particles ◽

Neighborhood Scale

Abstract. This study evaluates the influence of aerosol processes on the particle number (PN) concentrations in three major European cities on the temporal scale of one hour, i.e. on the neighborhood and city scales. We have used selected measured data of particle size distributions from previous campaigns in the cities of Helsinki, Oslo and Rotterdam. The aerosol transformation processes were evaluated using an aerosol dynamics model MAFOR, combined with a simplified treatment of roadside and urban atmospheric dispersion. We have compared the model predictions of particle number size distributions with the measured data, and conducted sensitivity analyses regarding the influence of various model input variables. We also present a simplified parameterization for aerosol processes, which is based on the more complex aerosol process computations; this simple model can easily be implemented to both Gaussian and Eulerian urban dispersion models. Aerosol processes considered in this study were (i) the coagulation of particles, (ii) the condensation and evaporation of n-alkanes, and (iii) dry deposition. The chemical transformation of gas-phase compounds was not taken into account. It was not necessary to model the nucleation of gas-phase vapors, as the computations were started with roadside conditions. Dry deposition and coagulation of particles were identified to be the most important aerosol dynamic processes that control the evolution and removal of particles. The effect of condensation and evaporation of organic vapors emitted by vehicles on particle numbers and on particle size distributions was examined. Under inefficient dispersion conditions, condensational growth contributed significantly to the evolution of PN from roadside to the neighborhood scale. The simplified parameterization of aerosol processes can predict particle number concentrations between roadside and the urban background with an inaccuracy of ∼ 10 %, compared to the fully size-resolved MAFOR model.

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Dry deposition and particle-size distributions of polycyclic aromatic hydrocarbons in the ambient air of a petrochemical plant

Journal of Aerosol Science ◽

10.1016/0021-8502(96)86905-9 ◽

1996 ◽

Vol 27 (4) ◽

pp. 650 ◽

Cited By ~ 2

Author(s):

Hwey-Lin Sheu ◽

Wen-Jhy Lee ◽

Huei-Chuang Chang ◽

Wen-Chun You

Keyword(s):

Particle Size ◽

Polycyclic Aromatic Hydrocarbons ◽

Aromatic Hydrocarbons ◽

Dry Deposition ◽

Ambient Air ◽

Petrochemical Plant ◽

Size Distributions ◽

Particle Size Distributions ◽

Polycyclic Aromatic

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Modeling and measurements of urban aerosol processes on the neighborhood scale in Rotterdam, Oslo and Helsinki

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-4817-2016 ◽

2016 ◽

Vol 16 (8) ◽

pp. 4817-4835 ◽

Cited By ~ 15

Author(s):

Matthias Karl ◽

Jaakko Kukkonen ◽

Menno P. Keuken ◽

Susanne Lützenkirchen ◽

Liisa Pirjola ◽

...

Keyword(s):

Particle Size ◽

Gas Phase ◽

Dry Deposition ◽

Particle Number ◽

Measured Data ◽

Size Distributions ◽

Particle Size Distributions ◽

Organic Vapors ◽

Coagulation Of Particles ◽

Neighborhood Scale

Abstract. This study evaluates the influence of aerosol processes on the particle number (PN) concentrations in three major European cities on the temporal scale of 1 h, i.e., on the neighborhood and city scales. We have used selected measured data of particle size distributions from previous campaigns in the cities of Helsinki, Oslo and Rotterdam. The aerosol transformation processes were evaluated using the aerosol dynamics model MAFOR, combined with a simplified treatment of roadside and urban atmospheric dispersion. We have compared the model predictions of particle number size distributions with the measured data, and conducted sensitivity analyses regarding the influence of various model input variables. We also present a simplified parameterization for aerosol processes, which is based on the more complex aerosol process computations; this simple model can easily be implemented to both Gaussian and Eulerian urban dispersion models. Aerosol processes considered in this study were (i) the coagulation of particles, (ii) the condensation and evaporation of two organic vapors, and (iii) dry deposition. The chemical transformation of gas-phase compounds was not taken into account. By choosing concentrations and particle size distributions at roadside as starting point of the computations, nucleation of gas-phase vapors from the exhaust has been regarded as post tail-pipe emission, avoiding the need to include nucleation in the process analysis. Dry deposition and coagulation of particles were identified to be the most important aerosol dynamic processes that control the evolution and removal of particles. The error of the contribution from dry deposition to PN losses due to the uncertainty of measured deposition velocities ranges from −76 to +64 %. The removal of nanoparticles by coagulation enhanced considerably when considering the fractal nature of soot aggregates and the combined effect of van der Waals and viscous interactions. The effect of condensation and evaporation of organic vapors emitted by vehicles on particle numbers and on particle size distributions was examined. Under inefficient dispersion conditions, the model predicts that condensational growth contributes to the evolution of PN from roadside to the neighborhood scale. The simplified parameterization of aerosol processes predicts the change in particle number concentrations between roadside and urban background within 10 % of that predicted by the fully size-resolved MAFOR model.

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