Atmospheric trace elements in aerosols observed over the Southern Ocean and coastal East Antarctica

Xu, Guang-Xin; Gao, Yuan

doi:10.3402/polar.v33.23973

Cited by 38 publications

(43 citation statements)

References 94 publications

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“…The results from this study are in good agreement with the data collected during field operations (Chen and Siefert 2004;Buck et al 2010;Xia and Gao 2011;Gao et al 2013;Xu and Gao 2014). Results from this study suggested that the mass ratio of oxalate concentration to the total Fe concentration should be at least 1 in order to attain the steady state production of photoreduced Fe(II).…”

Section: Comparison With Observational Datasupporting

confidence: 86%

“…Correlation between oxalate and soluble Fe(II) when the ratio of oxalate to total Fe is at least R Ratio R of oxalate to total Fe [Chen and Seifert] [ Xu and Gao, Gao et al] [ Xia and Gao] [ Buck et al] (Temperate) [Buck et al] (Tropical) Fig. 5 Empirical correlation between oxalate and soluble Fe(II) concentrations when the ratio between oxalate and total Fe is at least R, plotted against the parameter R. The data are collected from Buck et al (2010), Chen and Siefert (2004), Gao et al (2013), Gao (2008, 2011), Xu and Gao (2014) …”

Section: Resultsmentioning

confidence: 99%

“…Results from this study suggested that the mass ratio of oxalate concentration to the total Fe concentration should be at least 1 in order to attain the steady state production of photoreduced Fe(II). A study carried out by Xia and Gao (2011) at Newark in NJ, an urban location, where the average oxalate concentration was *4 times higher than the average concentration of the total Fe, shows that the oxalate concentration was highly correlated with the dissolved Fe(II) concentration (correlation coefficient = 0.90), whereas, in a remote Antarctic region, where the same ratio of oxalate to the total Fe was 0.16, the correlation between soluble Fe(II) and oxalate concentrations was significantly low (correlation coefficient = 0.03) (Gao et al 2013;Xu and Gao 2014). Similar pattern was observed over the North Atlantic (Chen and Siefert 2004), where the concentration ratio of oxalate to the total Fe was above 1, and the correlation coefficient between Fe(II) with oxalate was 0.35.…”

Section: Comparison With Observational Datamentioning

confidence: 96%

“…A comparison of relevant data from different studies is shown in Fig. 5 (Chen and Siefert 2004;Buck et al 2010;Xia and Gao 2011;Gao et al 2013;Xu and Gao 2014). The x-axis represents the ratio (R) of the oxalate concentrations to the total Fe concentrations and the y-axis represents the correlation coefficient between soluble Fe(II) with the oxalate with all data points where the ratios of oxalate to the total Fe were greater than R and at least 5 data points are available.…”

Section: Comparison With Observational Datamentioning

confidence: 99%

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Efficiency of organic ligands in adsorptive dissolution and photoreductive dissolution of hematite

Mukherjee

Gao

2016

Int. J. Environ. Sci. Technol.

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Organic ligands, especially oxalate, play an important role in iron dissolution from iron-containing minerals. To study the effects of organic acid ligands on the dissolution of iron-containing minerals, the dissolution kinetics of hematite in the presence of oxalate, acetate, and formate were studied under ultraviolet radiation with varying ligand concentrations (10-3 mM). The results indicate that for adsorption dissolution, oxalate is the dominating ligand for producing soluble iron (III) from hematite; for photoreductive dissolution under ultraviolet radiation and in oxic conditions, the production of iron (II) is highly proportional to the concentrations of oxalate, whereas the effects of varying concentrations of formate and acetate are not significant. At low oxalate concentrations (10-500 lM), the photoreductive dissolution of iron (II) is substantially low, while at high oxalate concentrations (3 mM), oxalate is equally effective as formate and acetate for producing photoreduced iron (II) from hematite. Combining with field data from other works, it is likely that the ratios of oxalate to total iron need to be higher than a threshold range of *1.2-5.5 in order for oxalate to effectively produce photoreduced iron (II) from hematite. This study demonstrates that the iron (II) yield from photoreduction of hematite is significantly lower when the hematite surface is pre-coated with organic ligands versus when it is exposed to ultraviolet radiation instantaneously.

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Section: Comparison With Observational Datasupporting

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Section: Comparison With Observational Datamentioning

confidence: 96%

Section: Comparison With Observational Datamentioning

confidence: 99%

See 2 more Smart Citations

Efficiency of organic ligands in adsorptive dissolution and photoreductive dissolution of hematite

Mukherjee

Gao

2016

Int. J. Environ. Sci. Technol.

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“…For instance, enrichment by Al, Fe, Mn, Ni, Cd, and Se was revealed in the eastern sector of the coastal part of Antarctica between China's Zhongshan Station and Australia's Casey Station (Xu and Yuan Gao, 2014). The coefficients of enrichment by Al, Fe, and Ni near the stations (K < 10) turned out to be comparable to or lower than data, which we obtained in the Arctic region A (K = 1-100).…”

Section: Element Areasupporting

confidence: 56%

On measurements of aerosol-gas composition of the atmosphere during two expeditions in 2013 along the Northern Sea Route

et al. 2015

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Abstract. We presented the results of expedition measurements of the set of physical-chemical characteristics of atmospheric aerosol in areas of the Arctic and Far East seas, performed onboard RV Akademik Fedorov (17 August-22 September 2013) and RV Professor Khljustin (24 July-7 September 2013). The specific features of spatial distribution and time variations of aerosol optical depth (AOD) of the atmosphere in the wavelength range of 0.34-2.14 µm and boundary layer height, aerosol and black carbon mass concentrations, and disperse and chemical composition of aerosol are discussed. Over the Arctic Ocean (on the route of RV Akademik Fedorov) there is a decrease in aerosol and black carbon concentrations in a northeastern direction: higher values were observed in the region of Spitsbergen and near the Kola Peninsula; and minimum values were observed at northern margins of the Laptev Sea. Average AOD (0.5 µm) values in this remote region were 0.03; the aerosol and black carbon mass concentrations were 875 and 22 ng m −3 , respectively. The spatial distributions of most aerosol characteristics over Far East seas show their latitudinal decrease in the northern direction. On transit of RV Professor Khljustin from the Japan Sea to the Chukchi Sea, the aerosol number concentration decreased on average from 23.7 to 2.5 cm −3 , the black carbon mass concentration decreased from 150 to 50 ng m −3 , and AOD decreased from 0.19 to 0.03. We analyzed the variations in the boundary layer height, measured by ship-based lidar: the average value was 520 m, and the maximal value was 1200 m. In latitudinal distribution of the boundary layer height, there is a characteristic minimum at a latitude of ∼ 55 • N. For water basins of eight seas, we present the chemical compositions of the water-soluble aerosol fraction (ions, elements) and small gasphase species, as well as estimates of their vertical fluxes. It is shown that substances are mainly (75-89 %) supplied from the atmosphere to the sea surface together with gas-phase species. The deposited ions account for from 11 to 24.5 %, and trace elements account for 0.2-0.4 % of the total sum of water-soluble components. The average vertical fluxes of aerosol substance are a factor of 4-7 larger in the Japan Sea than in the water basins of Arctic seas.

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Biological uptake, water mass mixing and scavenging prevent transport of manganese-rich waters from the Antarctic shelf

Latour

Merwe

Wuttig

et al. 2022

Preprint

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Manganese (Mn) is an essential element for photosynthetic life, yet concentrations in Southern Ocean open waters are very low, resulting from biological uptake along with limited external inputs. At southern latitudes, waters overlying the Antarctic shelf are expected to have much higher Mn concentrations due to their proximity to external sources such as sediment and sea ice. In this study, we investigated the potential export of Mn-rich Antarctic shelf waters toward depleted open Southern Ocean waters. Our results showed that while high Mn concentrations were observed over the shelf, strong biological uptake decreased dissolved Mn concentrations in surface waters north of the Southern Antarctic Circumpolar Current Front (< 0.1 nM), limiting export of shelf Mn to the open Southern Ocean. Conversely, in bottom waters, mixing between Mn-rich Antarctic Bottom Waters and Mn-depleted Low Circumpolar Deep Waters combined with scavenging processes led to a decrease in dissolved Mn concentrations with distance from the coast. Subsurface dissolved Mn maxima represented a potential reservoir for surface waters (0.3 -0.6 nM). However, these high subsurface values decreased with distance from the coast, suggesting these features may result from external sources near the shelf in addition to particle remineralization. Overall, these results imply that the lower-than-expected lateral export of trace metal-enriched waters contributes to the extremely low (< 0.1 nM) and potentially co-limiting Mn concentrations previously reported further north in this Southern Ocean region.

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Atmospheric trace elements in aerosols observed over the Southern Ocean and coastal East Antarctica

Cited by 38 publications

References 94 publications

Efficiency of organic ligands in adsorptive dissolution and photoreductive dissolution of hematite

Efficiency of organic ligands in adsorptive dissolution and photoreductive dissolution of hematite

On measurements of aerosol-gas composition of the atmosphere during two expeditions in 2013 along the Northern Sea Route

Biological uptake, water mass mixing and scavenging prevent transport of manganese-rich waters from the Antarctic shelf

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