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Journal ArticleDOI

Arctic air pollution: An overview of current knowledge

01 Jan 1986-Atmospheric Environment (Elsevier)-Vol. 20, Iss: 4, pp 643-663
TL;DR: In this paper, an estimate of the mean vertical profile of fine particle aerosol mass during March and April shows that, on average, pollution is concentrated in the lower 5 km of the atmosphere.
About: This article is published in Atmospheric Environment.The article was published on 1986-01-01. It has received 654 citations till now. The article focuses on the topics: Arctic haze & Arctic.
Citations
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Journal ArticleDOI
TL;DR: Reducing soot emissions, thus restoring snow albedos to pristine high values, would have the double benefit of reducing global warming and raising the global temperature level at which dangerous anthropogenic interference occurs.
Abstract: Plausible estimates for the effect of soot on snow and ice albedos (1.5% in the Arctic and 3% in Northern Hemisphere land areas) yield a climate forcing of +0.3 W/m2 in the Northern Hemisphere. The “efficacy” of this forcing is ∼2, i.e., for a given forcing it is twice as effective as CO2 in altering global surface air temperature. This indirect soot forcing may have contributed to global warming of the past century, including the trend toward early springs in the Northern Hemisphere, thinning Arctic sea ice, and melting land ice and permafrost. If, as we suggest, melting ice and sea level rise define the level of dangerous anthropogenic interference with the climate system, then reducing soot emissions, thus restoring snow albedos to pristine high values, would have the double benefit of reducing global warming and raising the global temperature level at which dangerous anthropogenic interference occurs. However, soot contributions to climate change do not alter the conclusion that anthropogenic greenhouse gases have been the main cause of recent global warming and will be the predominant climate forcing in the future.

1,225 citations

Journal ArticleDOI
14 Jul 1988-Nature
TL;DR: In this paper, the authors focus on recent ground-level observations from the Canadian baseline station at Alert (82.5° N, 62.3° W) and from aircraft that show that ozone destruction is occurring under the Arctic surface radiation inversion during March and April as the Sun rises.
Abstract: There is increasing evidence that at polar sunrise sunlight-induced changes in the composition of the lower Arctic atmosphere (0–2 km) are taking place that are important regarding the tropospheric cycles of ozone, bromine, sulphur oxides1, nitrogen oxides2 and possibly iodine3. Here we focus on recent ground-level observations from the Canadian baseline station at Alert (82.5° N, 62.3° W) and from aircraft that show that ozone destruction is occurring under the Arctic surface radiation inversion during March and April as the Sun rises. The destruction might be linked to catalytic reactions of BrOx radicals and the photochemistry of bromoform, which appears to have a biological origin in the Arctic Ocean. This may clarify previously unexplained regular springtime occurrences of ozone depletion at ground level in a 10-year data record at Barrow, Alaska4, as well as peaks in aerosol bromine observed throughout the Arctic in March and April3. Current information does not allow us to offer more than a speculative explanation for the chemical mechanisms leading to these phenomena.

939 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe the Arctic temperature and humidity characteristics, cloud properties and processes, radiative characteristics of the atmosphere and surface, direct and indirect radiative effects of aerosols, and the modeling and satellite remote sensing of cloud and radiative properties.
Abstract: To provide a background for ARM's activities at the North Slope of Alaska/Adjacent Arctic Ocean sites, an overview is given of our current state of knowledge of Arctic cloud and radiation properties and processes. The authors describe the Arctic temperature and humidity characteristics, cloud properties and processes, radiative characteristics of the atmosphere and surface, direct and indirect radiative effects of aerosols, and the modeling and satellite remote sensing of cloud and radiative characteristics. An assessment is given of the current performance of satellite remote sensing and climate modeling in the Arctic as related to cloud and radiation issues. Radiation-climate feedback processes are discussed, and estimates are made of the sign and magnitude of the individual feedback components. Future plans to address these issues are described.

771 citations

Journal ArticleDOI
TL;DR: A review of the state of scientific understanding in relation to global and regional air quality is outlined in this article, in terms of emissions, processing and transport of trace gases and aerosols.

760 citations

Journal ArticleDOI
TL;DR: In this article, the Lagrangian particle dispersion model FLEXPART was used to construct a global data set of 1.4 million continuous trajectories and a climatology of transport in and to the Arctic was developed.
Abstract: [1] The Lagrangian particle dispersion model FLEXPART was used to construct a global data set of 1.4 million continuous trajectories. At the model start, particles were distributed homogeneously in the atmosphere and were then transported for 5.5 years using both resolved winds from European Centre for Medium-Range Weather Forecasts analyses and parameterized turbulent and convective transport. On the basis of this data set, a climatology of transport in and to the Arctic was developed. It was found that the time air resides continuously north of 70°N, called its Arctic age, is highest near the surface in the North American sector of the Arctic. North of 80°N and near the surface, the mean Arctic age of air is about 1 week in winter and 2 weeks in summer. It decreases rapidly with altitude to about 3 days in the upper troposphere. In the most isolated regions of the Arctic, air is exposed to continuous darkness for, on average, 10–14 days in December. Transport from the stratosphere to the lower troposphere is much slower in the Arctic than in the middle latitudes. In the central Arctic, for instance, the probability that air near the surface was transported from the stratosphere within 10 days is only about 1% in winter and 0.3% in summer. Air pollution can be transported into the Arctic along three different pathways: low-level transport followed by ascent in the Arctic, low-level transport alone, and uplift outside the Arctic, followed by descent in the Arctic. Only this last pathway is frequent for pollution originating from North America and Asia, whereas European pollution can follow all three pathways in winter, and pathways one and three in summer. Sensitivities of Arctic air masses to emissions of air pollutants, based on transport alone, were calculated for times of up to 30 days before the air masses reached the Arctic. They were highest over Siberia and Europe in winter and over the oceans in summer. Using an inventory for anthropogenic black carbon (BC) emissions, it was found that near the surface and for transport timescales of 5 and 10 days, BC source contributions from south Asia are only 1.6% and 10%, respectively, of the corresponding European values, despite much higher emissions in south Asia. Using an inventory for BC emissions from forest fires, BC source contributions to the Arctic, particularly from fires in Siberia, were larger than anthropogenic BC source contributions in summer in years of average burning.

709 citations


Cites background or result from "Arctic air pollution: An overview o..."

  • ...On the one hand, it has been realized that there is strong southnorth transport over Eurasia [Rahn, 1981; Barrie, 1986]; on the other hand it was also argued that the Arctic lower troposphere is well isolated because the isentropes form a closed dome over the Arctic that cannot easily be penetrated…...

    [...]

  • ...This is consistent with the average wind patterns [Macdonald et al., 2005] and a mainly Eurasian source of low-level Arctic air pollution in winter [Barrie, 1986; Eckhardt et al., 2003]....

    [...]

  • ...This rules out most of the world’s pollution source regions because they are too warm, and leaves northern Eurasia as the main source region for the Arctic Haze [Rahn, 1981; Barrie, 1986]....

    [...]

  • ...0148-0227/06/2005JD006888$09.00 D11306 1 of 17 same low potential temperatures as the Arctic Haze layers [Carlson, 1981; Iversen, 1984; Barrie, 1986]....

    [...]

References
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Book
01 Jan 1963

1,482 citations

Journal ArticleDOI
TL;DR: The Global Precipitation Chemistry Project collects precipitation by event to determine composition and processes controlling it in five remote areas as mentioned in this paper, including Bermuda, Australia, Poker Flat, Alaska, and Amsterdam Island.
Abstract: The Global Precipitation Chemistry Project collects precipitation by event to determine composition and processes controlling it in five remote areas. Compositions (excluding sea-salt) at St. Georges, Bermuda, were primarily controlled by anthropogenic processes; composition and acidities at San Carlos, Venezuela, Katherine, Australia, Poker Flat, Alaska, and Amsterdam Island were controlled by unknown mixtures of natural or anthropogenic processes. Precipitation was acidic; average volume-weighted pH values were 4.8 for Bermuda; 5.0, Alaska; 4.9, Amsterdam Island; 4.8, Australia; 4.8, Venezuela. Acidities at Bermuda and Alaska were from long-range transport of sulfate aerosol; at Venezuela, Australia, and Amsterdam Island, from mixtures of weak organic and strong mineral acids, primarily H/sub 2/SO/sub 4/. Relative proportions of weak to strong acids were largest at Venezuela and lowest at Amsterdam Island. Weak and strong acids were from mixtures of natural and anthropogenic processes. Once contributions from human activities were removed, the lower limit of natural contributions was probably greater than or equal to pH 5.

669 citations

Journal ArticleDOI
01 Nov 1980-Nature
TL;DR: This paper showed that clustered volcanic eruptions have a considerable cooling effect on climate, which further complicates climatic predictions, and used a temperature index to measure the cooling effect of volcanic activity.
Abstract: Acidity profiles along well dated Greenland ice cores reveal large volcanic eruptions in the Northern Hemisphere during the past 10,000 yr. Comparison with a temperature index shows that clustered eruptions have a considerable cooling effect on climate, which further complicates climatic predictions.

586 citations

Journal ArticleDOI
TL;DR: In this paper, it was shown that during winters with little or no snowmelt before spring, most of the pollutant load is retained in the snowpack and the average concentration of pollutants in this fraction is 2-2.5 times the concentration in the entire snowpack.
Abstract: Over much of Norway a large portion of the yearly precipitation falls as snow, and the pollutants contained in precipitation accumulate in the snowpack to be released during a short period in spring. Atmospheric fallout of sulfur compounds has been estimated to be about 30% of the total deposition in Norway, but fallout on the snow cover is probably considerably smaller. During winters with little or no snowmelt before spring, most of the pollutant load is retained in the snowpack. Laboratory and field lysimeter experiments indicate that 50–80% of the pollutant load is released with the first 30% of the meltwater. The average concentration of pollutants in this fraction is 2–2.5 times the concentration in the snowpack itself. The very first fractions may contain more than 5 times the snowpack concentrations. These high concentrations may be due to a freeze-concentration process during snow recrystallization and melting in which contaminants accumulate preferentially at the surfaces of ice particles. The resulting increase in the acid concentration of low-buffered water courses occasionally leads to severe physiological stress to fish and other aquatic organisms and even to massive fish kills. This process occurs at a time which is critical to the hatching stage of salmonid fish species.

487 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reported measurements of light-absorbing material in the Arctic snowpack for longitudes from 25 E to 160 W. The contributions to light absorption due to natural crustal and soot aerosol are identified by their wavelength dependence.

392 citations