Atmospheric Inputs Of Trace Elements Research Articles

Concentrations, particle-size distributions, and dry deposition fluxes of aerosol trace elements over the Antarctic Peninsula in austral summer

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.

The effects of lithology on trace element and REE behavior during tropical weathering

The thick regolith developed in the humid tropics represents an endmember of critical zone evolution, where shallow and deep biogeochemical cycles can be decoupled in terms of the predominant source of trace elements (atmospheric input at the surface, weathering at depth) and of the processes that control their cycling. To investigate the influence of lithology on trace element behavior and in this potential decoupling, we studied two deep (9.3 and 7.5 m), highly-leached, ridgetop regolith profiles at the Luquillo Critical Zone Observatory, Puerto Rico. These profiles have comparable internal (degree of weathering, topography) and external (vegetation, climate) characteristics, but differ in their underlying bedrock (andesitic volcaniclastic and granitic). At these two sites, we analyzed a large suite of trace elements and used the rare earth elements and yttrium (REY) as tracers of critical zone processes because they are fractionated by the chemical reactions involved in weathering and pedogenesis (e.g., sorption, dissolution, colloidal transport) and by redox fluctuations.We found that both regolith profiles show atmospheric inputs of trace elements at the surface and evidence of bedrock dissolution at depth, as expected. We also found noticeable differences in the re-distribution of trace elements and REY within the profiles, indicative of different geochemical environments with depth and lithology. In the volcaniclastic profile, trace element and REY behavior is controlled mainly by redox-mediated, sorption/desorption reactions, whereas pH-controlled dissolution/precipitation and sorption reactions predominate in the granitic profile. The most noticeable difference between the two regolith profiles is in the long-term redox conditions, inferred from redox-sensitive elements and Ce anomaly variations, which are more variable and stratified in the volcaniclastic profile and change gradually with depth in the granitic profile. The contrasting redox conditions and the different sources of elements (dust vs. bedrock) produce a decoupling between the surface and deep geochemical environments of the volcaniclastic regolith. The difference in redox conditions between the two lithologies likely stems from the finer grain size and higher clay content of the volcaniclastic regolith.

Atmospheric transport of trace elements and nutrients to the oceans

This paper reviews atmospheric inputs of trace elements and nutrients to the oceans in the context of the GEOTRACES programme and provides new data from two Atlantic GEOTRACES cruises. We consider the deposition of nitrogen to the oceans, which is now dominated by anthropogenic emissions, the deposition of mineral dust and related trace elements, and the deposition of other trace elements which have a mixture of anthropogenic and dust sources. We then consider the solubility (as a surrogate for bioavailability) of the various elements. We consider briefly the sources, atmospheric transport and transformations of these elements and how this results in strong spatial deposition gradients. Solubility of the trace elements also varies systematically between elements, reflecting their sources and cycling, and for some trace elements there are also systematic gradients in solubility related to dust loading. Together, these effects create strong spatial gradients in the inputs of bioavailable trace elements to the oceans, and we are only just beginning to understand how these affect ocean biogeochemistry.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

Effects of Asian dust on the atmospheric input of trace elements to the East China Sea

The long-range transport of Asian dust (AD) can carry large quantities of trace elements to the marginal seas of the Northwest Pacific, and the deposition of soluble fractions of aerosol elements may significantly impact the primary productivity and ecosystem structure. Samples of total suspended particulates (TSP) and size-segregated aerosols were collected synchronously at Huaniao Island in the East China Sea (ECS) between April 2010 and March 2011 and then analyzed for the total and soluble fractions of 14 trace elements. Twelve AD events were identified in the spring and autumn of the sampling year based on official records of AD storms from the China Meteorological Administration and verified by the high Al concentration in the aerosol samples. The dry deposition flux of the total or soluble fraction of each analyzed aerosol element was estimated using its concentration in the TSP samples and dry deposition velocity derived from the size-segregated samples. The dry deposition velocity varied from 0.7cms−1 for total Pb to 1.5cms−1 for total Al based on the mass median diameters (MMD) of 1.6 and 4.9μm, respectively, of associated particles. During AD events, the mean concentrations of the total and soluble fractions of Al, Fe, Mn, P and Ba increased significantly and led to enhanced dry deposition fluxes of these elements to the ECS (over a factor of 3 for the total and over 30% for the soluble fraction). The concentrations of the soluble fractions of anthropogenically derived elements (As, Cd, Cu, Pb, V and Zn) during AD events were lower than at other times and resulted in lower dry deposition fluxes. Asian dust events were associated with higher than average dry deposition fluxes of soluble Fe and P and lower fluxes of soluble Cu and Zn.

Identifying the origin of atmospheric inputs of trace elements in the Prades Mountains (Catalonia) with bryophytes, lichens, and soil monitoring

The biomonitors Hypnum cupressiforme and Xanthoria parietina were used to assess the deposition of trace elements and their possible origin in the Prades Mountains, a protected Mediterranean forest area of NE Spain with several pollution sources nearby. Al, As, Cd, Co, Cu, Cr, Ni, Pb, Sb, Ti, V, and Zn were determined in 16 locations within this protected area. Soil trace element concentrations were also ascertained to calculate enrichment factors (EF) and use them to distinguish airborne from soilborne trace element inputs. In addition, lichen richness was measured to further assess atmospheric pollution. EF demonstrated to be useful not only for the moss but also for the lichen. Cd, Cr, Cu, Ni, and Zn presented values higher than three in both biomonitors. These trace elements were also the main ones emitted by the potential sources of pollutants. The distance between sampling locations and potential pollution sources was correlated with the concentrations of Cu, Sb, and Zn in the moss and with Cr, Ni, and Sb in the lichen. Lichen richness was negatively correlated with lichen Cu, Pb, and V concentrations on dry weight basis. The study reflected the remarkable influence that the pollution sources have on the presence of trace elements and on lichen species community composition in this natural area. The study highlights the value of combining the use of biomonitors, enrichment factors, and lichen diversity for pollution assessment to reach a better overview of both trace elements' impact and the localization of their sources.

Atmospheric Deposition of Nutrients and Trace Elements to the Coastal Oceans: A Review

Atmospheric transport and deposition of pollutants to the coastal oceans increase dramatically due to the impacts of climate change and human activities. The paper summarizes a number of researches after 1997 on the atmospheric inputs of nutrients and trace elements to the world coastal oceans with emphasis on the eastern China seas. The atmospheric fluxes of nitrogen and phosphorus to the coastal oceans range from 13 to 73 mmol N /( m2. a) and 0. 11 to 1. 6 mmol P /( m2.a) ,respectively. North Sea appears to be influenced by relatively higher atmospheric flux of nitrogen ( 70 mmol N /( m2.a) ) compared to the eastern coast of North America ( 50 mmol N / ( m2.a) ) and eastern China seas ( 50 mmol N /( m2.a) ). Mediterranean Sea and the Gulf of Aqaba ( Red Sea) receive the lowest fluxes of nitrogen as well as phosphorus from the atmosphere. The deposition fluxes of trace elements vary significantly in both time and space with the highest flux approximately 3 orders of magnitude higher than the lowest one. The flux variations of crustal-dominated trace elements such as Al and Fe are strongly related to the dust transport and agricultural activities of adjacent land,while atmospheric fluxes of non-crustal trace elements like Cd,Zn and Pb are mainly determined by industrial and mobile emissions. Atmospheric inputs of trace elements can partly dissolve into the seawater with the solubility ranging from a few percent to 50% and that portion may become bioavailable and thereby influence the costal ecosystem. For many coastal oceans including East China Sea and Yellow Sea,atmospheric fluxes of nutrients and certain trace elements may exceed their riverine inputs. Atmospheric deposition contributes significantly to the coastal eutrophication,and its episodic nature can enhance primary productivity within a short period,which may induce a harmful algal bloom ( red tide). Trace element deposition may have toxic effects on specific phytoplankton and influence both primary productivity and ecosystem structure of the coastal area. Further studies should be conducted for accurate estimation of atmospheric fluxes of various pollutants to the coastal oceans and for understanding their roles in marine phytoplankton growth.

The rouge river watershed pollution by trace elements: atmospheric depositions and emission sources

Atmospheric inputs of trace elements to the Rouge River watershed by particle dry deposition and aerosol scavenging by precipitation were presented along with the annual emission of trace elements to the atmosphere by emission source category. A dynamic physical-based model was used to evaluate the dry and wet deposition flux of particle-segregated trace elements and its temporal and spatial variation in the Rouge River watershed from 1982 to 1992. Annual emissions of trace elements to the atmosphere were estimated assuming a controlled status for all the emission sources which include coal and oil combustion utilities, iron-steel manufacturing plants, metal production from primary and secondary pyrometallurgical processes, cement manufacturing, solid waste and sewage sludge incinerators. In general, there is a good agreement between the trend in the atmospheric input (dry + wet deposition fluxes) to the Rouge River watershed and that in the annual emission of trace elements to the atmosphere with r2 in the range of 0.84 to 0.98. Atmospheric inputs and emissions are following downward trends for Pb, whereas for Cd, Cr, Ni and Hg show a steady increase since 1987/1988. The modeled long-term average of the total (dry + wet) deposition flux of trace elements to the Rouge River watershed is 3167 ± 2548 g km−2 yr−1 for Pb, 397 ± 132 g km−2 yr−1 for Ni, 350 ± 160 g km−2 yr−1 for Cr, 130 ± 39 g km−2 yr−1 for Cd, and 8.6 ± 3.7 g km−2 yr−1 for Hg.

The rouge river watershed pollution by trace elements: Atmospheric depositions and emission sources

Atmospheric inputs of trace elements to the Rouge River watershed by particle dry deposition and aerosol scavenging by precipitation were presented along with the annual emission of trace elements to the atmosphere by emission source category. A dynamic physical-based model was used to evaluate the dry and wet deposition flux of particle-segregated trace elements and its temporal and spatial variation in the Rouge River watershed from 1982 to 1992. Annual emissions of trace elements to the atmosphere were estimated assuming a controlled status for all the emission sources which include coal and oil combustion utilities, iron-steel manufacturing plants, metal production from primary and secondary pyrometallurgical processes, cement manufacturing, solid waste and sewage sludge incinerators. In general, there is a good agreement between the trend in the atmospheric input (dry + wet deposition fluxes) to the Rouge River watershed and that in the annual emission of trace elements to the atmosphere with r2 in the range of 0.84 to 0.98. Atmospheric inputs and emissions are following downward trends for Pb, whereas for Cd, Cr, Ni and Hg show a steady increase since 1987/1988. The modeled long-term average of the total (dry + wet) deposition flux of trace elements to the Rouge River watershed is 3167 ±2548 g km−2 yr−1 for Pb, 397 ±132 g km−2 yr−1 for Ni, 350 ± 160 g km−2 yr−1 for Cr, 130 ±39 g km−2 yr−1 for Cd, and 8.6 ±3.7 g km−2 yr−1 for Hg.

Atmospheric concentrations and deposition of heavy metals over the North Sea: A literature review

A literature review of the atmospheric concentration rates and dry and wet deposition fluxes of particulate Cd, Cr, Cu, Pb and Zn to the North Sea and adjacent areas is given. The results of direct measurements of dry and wet deposition fluxes are compared to indirect estimates and to modelling values. This work points out the large uncertainties in results of different studies on atmospheric input of trace elements into the North Sea. The current knowledge about the dependence of the deposition velocity upon the particle size and about the processes controlling wet deposition fluxes, and the quality and completeness of the emission data are still inadequate for describing the environmental cycle and impact of heavy metals in the North Sea.

Atmospheric inputs of trace elements and the geochemistry of the Mediterranean sea

Atmospheric inputs of trace elements and the geochemistry of the Mediterranean sea