Arctic lower tropospheric aerosol trends and composition at Alert, Canada: 1980–1995

Sirois, A.; Barrie, Leonard A.

doi:10.1029/1999jd900077

Cited by 213 publications

(299 citation statements)

References 73 publications

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“…Bootstrapping analysis found little error associated with this factor. Furthermore, similar marine factors have been observed in previous apportionment studies of Arctic snow (Hegg et al, 2009(Hegg et al, , 2010 and Arctic aerosol (Sirois and Barrie, 1999;Nguyen et al, 2013). …”

Section: Factor 1: Sea Saltsupporting

confidence: 61%

“…The seven-factor solution for this factor showed low levels of error according to the bootstrapping analysis. Similar factors have been observed in previous atmospheric apportionment studies (e.g., Sirois and Barrie, 1999;Nguyen et al, 2013) but typically were not seen to account for such a large percentage of these metals, i.e., with loadings of 25-60 % m/m for major crustal analytes. This might suggest that a separate source was missed by this study, though this seems unlikely given the consistency of the observed factor.…”

Section: Factor 2: Crustal Metalssupporting

confidence: 61%

“…However, direct measurements of pollutants in Arctic snow have been less common, particularly sampling campaigns of fresh snow. The relative abundance of Arctic aerosol data has facilitated extensive research on particulate sources (e.g., Sirois and Barrie, 1999;Stohl et al, 2013;Nguyen et al, 2013;Yttri et al, 2014). Fewer studies have identified the sources of snow impurities, which represent the deposited and surface albedoinfluencing portion of the aerosol, and often these studies are reliant on modelled snow concentrations (e.g., Skeie et al, 2011;Wang et al, 2011) rather than measurements (e.g., Hegg et al, 2009Hegg et al, , 2010.…”

Section: Introductionmentioning

confidence: 99%

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Temporally delineated sources of major chemical species in high Arctic snow

et al. 2018

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Abstract. Long-range transport of aerosol from lower latitudes to the high Arctic may be a significant contributor to climate forcing in the Arctic. To identify the sources of key contaminants entering the Canadian High Arctic an intensive campaign of snow sampling was completed at Alert, Nunavut, from September 2014 to June 2015. Fresh snow samples collected every few days were analyzed for black carbon, major ions, and metals, and this rich data set provided an opportunity for a temporally refined source apportionment of snow composition via positive matrix factorization (PMF) in conjunction with FLEXPART (FLEXible PARTicle dispersion model) potential emission sensitivity analysis. Seven source factors were identified: sea salt, crustal metals, black carbon, carboxylic acids, nitrate, noncrustal metals, and sulfate. The sea salt and crustal factors showed good agreement with expected composition and primarily northern sources. High loadings of V and Se onto Factor 2, crustal metals, was consistent with expected elemental ratios, implying these metals were not primarily anthropogenic in origin. Factor 3, black carbon, was an acidic factor dominated by black carbon but with some sulfate contribution over the winter-haze season. The lack of K + associated with this factor, a Eurasian source, and limited known forest fire events coincident with this factor's peak suggested a predominantly anthropogenic combustion source. Factor 4, carboxylic acids, was dominated by formate and acetate with a moderate correlation to available sunlight and an oceanic and North American source. A robust identification of this factor was not possible; however, atmospheric photochemical reactions, ocean microlayer reaction, and biomass burning were explored as potential contributors. Factor 5, nitrate, was an acidic factor dominated by NO − 3 , with a likely Eurasian source and mid-winter peak. The isolation of NO − 3 on a separate factor may reflect its complex atmospheric processing, though the associated source region suggests possibly anthropogenic precursors. Factor 6, non-crustal metals, showed heightened loadings of Sb, Pb, and As, and correlation with other metals traditionally associated with industrial activities. Similar to Factor 3 and 5, this factor appeared to be largely Eurasian in origin. Factor 7, sulfate, was dominated by SO 2− 4 and MS with a fall peak and high acidity. Coincident volcanic activity and northern source regions may suggest a processed SO 2 source of this factor.

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Section: Factor 1: Sea Saltsupporting

confidence: 61%

Section: Factor 2: Crustal Metalssupporting

confidence: 61%

Section: Introductionmentioning

confidence: 99%

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Temporally delineated sources of major chemical species in high Arctic snow

et al. 2018

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“…The atmosphere is the fastest and most direct route from the source of pollution: transport from the sources to the Arctic occurs in a matter of days or weeks (Pfirman et al, 1995;AMAP, 1997;Macdonald et al, 2000). *Corresponding author. Numerous studies have shown that aerosols in the Arctic are important for atmospheric chemistry and climate (Rahn, 1981;Barrie, 1986Barrie, , 1996Pacyna, 1991;Leck et al, 1996;Sirois and Barrie, 1999;Bigg and Leck, 2001). There is much evidence that atmospheric inputs contribute significantly to the chemical budget of marine areas (Duce et al, 1991;Lisitzin, 1996), but in the Arctic their role is underestimated.…”

Section: Introductionmentioning

confidence: 99%

Heavy metals in aerosols over the seas of the Russian Arctic

Шевченко

Lisitzin

Виноградова

et al. 2003

Science of The Total Environment

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A review of the data on heavy metals in aerosols over the seas of the Russian Arctic is presented. Results of heavy metal studies in aerosols obtained during 11 research expeditions in summeryautumn period from 1991 to 2000, and at Severnaya Zemlya and Wrangel Island in spring, in 1985-1989 are discussed. Concentrations of most heavy metals in the atmosphere in the marine boundary layer in the Russian Arctic are nearly of the same order as literature data from other Arctic areas. The content of heavy metals in the aerosols over the seas of the Russian Arctic shows an annual variation with maximal concentrations during the winteryspring season. In the summeryautumn period increased concentrations of heavy metals could be explained, in most cases, by natural processes (generation of sea salt aerosols, etc.). In some cases, aerosols from Norilsk and Kola Peninsula were detected. Particular attention was paid to estimation of horizontal and vertical fluxes of atmospheric heavy metals. We estimated annual variations in long-range transport of heavy metals into the Russian Arctic in 1986-1995. In winter and spring, up to 50% of the average air pollutant concentrations in the Russian Arctic are due to the Arctic atmospheric pollution itself. Moreover, the monthly and annual averaged fluxes of six anthropogenic chemical elements (arsenic, nickel, lead, vanadium, zinc and cadmium) onto the surface in the Arctic were estimated, and the values obtained were in reasonable agreement with the literature data available. ᮊ

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“…The choice of the month of February is motivated by two factors that favour the DGF: cold temperature and high concentration of acidic aerosols (Sirois and Barrie, 1999). 1D simulations have also shown that the DGF is the strongest in February .…”

Section: Design Of the Experimentsmentioning

confidence: 99%

Assessment of the dehydration‐greenhouse feedback over the Arctic during February 1990

Girard

Stefanof

2006

Intl Journal of Climatology

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Abstract:The effect of pollution-derived sulfuric acid aerosols on the aerosol-cloud-radiation interactions is investigated over the Arctic for February 1990. Observations suggest that acidic aerosols can decrease the heterogeneous nucleation rate of ice crystals and lower the homogeneous freezing temperature of haze droplets. On the basis of these observations, we hypothesize that the cloud thermodynamic phase is modified in polluted air mass (Arctic haze). Cloud ice number concentration is reduced, thus promoting further ice crystal growth by the Bergeron-Findeisen process. Hence, ice crystals reach larger sizes and low-levkel ice crystal precipitation from mixed-phase clouds increases. Enhanced dehydration of the lower troposphere contributes to decreased water vapour greenhouse effect and cools the surface. A positive feedback is created between surface cooling and air dehydration, accelerating cold air production. This process is referred to as the dehydration-greenhouse feedback (DGF).Simulations performed using an Arctic regional climate model for February 1990 are used to assess the potential effect of the DGF on the Arctic climate during February. Results show that the DGF has an important effect on cloud, atmospheric dehydration, and temperature over the Central and Eurasian Arctic, which is the coldest part of the Arctic. Cloud ice is significantly reduced and the total atmospheric water path is decreased by as much as 12%. This results in a surface cooling ranging between 0 and −3 K. Moreover, the lower tropospheric cooling over the Eurasian and Central Arctic strengthens the atmospheric circulation at the upper level, thus increasing the aerosol transport from the mid-latitudes and enhancing the DGF. Over warmer areas, the increased aerosol concentration (caused by the DGF) leads to longer cloud lifetime, which contributes to warm these areas.

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Arctic lower tropospheric aerosol trends and composition at Alert, Canada: 1980–1995

Abstract: aerosol components are associated with lower tropospheric ozone depletion at polar sunrise. In autumn, aerosol iodine but not bromine has a secondary peak.

Cited by 213 publications

References 73 publications

Temporally delineated sources of major chemical species in high Arctic snow

Temporally delineated sources of major chemical species in high Arctic snow

Heavy metals in aerosols over the seas of the Russian Arctic

Assessment of the dehydration‐greenhouse feedback over the Arctic during February 1990

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