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A 300-million-year record of atmospheric carbon dioxide from fossil plant cuticles.

https://arctichealth.org/en/permalink/ahliterature95961
Source
Nature. 2001 May 17;411(6835):287-90
Publication Type
Article
Date
May-17-2001
Author
Retallack G J
Author Affiliation
Department of Geological Sciences, University of Oregon, Eugene 97403-1272, USA. gregr@darkwing.uoregon.edu
Source
Nature. 2001 May 17;411(6835):287-90
Date
May-17-2001
Language
English
Publication Type
Article
Keywords
Atmosphere - chemistry
Carbon Dioxide - metabolism
Cold Climate
Fossils
Ginkgo biloba - cytology - growth & development - metabolism
Greenhouse Effect
Ice
Methane - metabolism
Phylogeny
Plant Leaves - cytology - growth & development - metabolism
Plants, Medicinal
Pollen
Seasons
Water - metabolism
Abstract
To understand better the link between atmospheric CO2 concentrations and climate over geological time, records of past CO2 are reconstructed from geochemical proxies. Although these records have provided us with a broad picture of CO2 variation throughout the Phanerozoic eon (the past 544 Myr), inconsistencies and gaps remain that still need to be resolved. Here I present a continuous 300-Myr record of stomatal abundance from fossil leaves of four genera of plants that are closely related to the present-day Ginkgo tree. Using the known relationship between leaf stomatal abundance and growing season CO2 concentrations, I reconstruct past atmospheric CO2 concentrations. For the past 300 Myr, only two intervals of low CO2 (2,000 p.p.m.v.) concentrations. These results are consistent with some reconstructions of past CO2 (refs 1, 2) and palaeotemperature records, but suggest that CO2 reconstructions based on carbon isotope proxies may be compromised by episodic outbursts of isotopically light methane. These results support the role of water vapour, methane and CO2 in greenhouse climate warming over the past 300 Myr.
Notes
Comment In: Nature. 2001 May 17;411(6835):247-811357108
PubMed ID
11357126 View in PubMed
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All-time releases of mercury to the atmosphere from human activities.

https://arctichealth.org/en/permalink/ahliterature129775
Source
Environ Sci Technol. 2011 Dec 15;45(24):10485-91
Publication Type
Article
Date
Dec-15-2011
Author
David G Streets
Molly K Devane
Zifeng Lu
Tami C Bond
Elsie M Sunderland
Daniel J Jacob
Author Affiliation
Decision and Information Sciences Division, Argonne National Laboratory, Argonne, Illinois, United States. dstreets@anl.gov
Source
Environ Sci Technol. 2011 Dec 15;45(24):10485-91
Date
Dec-15-2011
Language
English
Publication Type
Article
Keywords
Air Pollutants - toxicity
Air Pollution - statistics & numerical data
Atmosphere - chemistry
Environmental monitoring
Humans
Mercury - analysis
Mining - statistics & numerical data
Power Plants - statistics & numerical data
Water Pollutants, Chemical - analysis
Water Pollution, Chemical - statistics & numerical data
Abstract
Understanding the biogeochemical cycling of mercury is critical for explaining the presence of mercury in remote regions of the world, such as the Arctic and the Himalayas, as well as local concentrations. While we have good knowledge of present-day fluxes of mercury to the atmosphere, we have little knowledge of what emission levels were like in the past. Here we develop a trend of anthropogenic emissions of mercury to the atmosphere from 1850 to 2008-for which relatively complete data are available-and supplement that trend with an estimate of anthropogenic emissions prior to 1850. Global mercury emissions peaked in 1890 at 2600 Mg yr(-1), fell to 700-800 Mg yr(-1) in the interwar years, then rose steadily after 1950 to present-day levels of 2000 Mg yr(-1). Our estimate for total mercury emissions from human activities over all time is 350 Gg, of which 39% was emitted before 1850 and 61% after 1850. Using an eight-compartment global box-model of mercury biogeochemical cycling, we show that these emission trends successfully reproduce present-day atmospheric enrichment in mercury.
Notes
Cites: Environ Sci Technol. 2002 Jun 1;36(11):2303-1012075781
Cites: Chemosphere. 2002 Jul;48(1):51-712137057
Cites: Environ Sci Technol. 2003 Jan 1;37(1):22-3112542286
Cites: J Environ Monit. 2003 Dec;5(6):935-4914710936
Cites: Environ Sci Technol. 2006 Sep 1;40(17):5312-816999104
Cites: Environ Sci Technol. 2011 Mar 15;45(6):2042-721355558
Cites: Environ Sci Technol. 2008 Aug 15;42(16):5971-718767653
Cites: Environ Sci Technol. 2009 Apr 15;43(8):2983-819475981
Cites: Proc Natl Acad Sci U S A. 2009 Jun 2;106(22):8830-419451629
Cites: Environ Sci Technol. 2010 Apr 15;44(8):2918-2420345131
Cites: Environ Sci Technol. 2010 Nov 15;44(22):8574-8020973542
Cites: Environ Sci Technol. 2007 Nov 15;41(22):7632-818075067
PubMed ID
22070723 View in PubMed
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An aerosol particle containing enriched uranium encountered in the remote upper troposphere.

https://arctichealth.org/en/permalink/ahliterature289883
Source
J Environ Radioact. 2018 Apr; 184-185:95-100
Publication Type
Journal Article
Date
Apr-2018
Author
D M Murphy
K D Froyd
E Apel
D Blake
N Blake
N Evangeliou
R S Hornbrook
J Peischl
E Ray
T B Ryerson
C Thompson
A Stohl
Author Affiliation
NOAA ESRL Chemical Sciences Division, Boulder, CO, USA. Electronic address: daniel.m.murphy@noaa.gov.
Source
J Environ Radioact. 2018 Apr; 184-185:95-100
Date
Apr-2018
Language
English
Publication Type
Journal Article
Keywords
Aerosols - analysis
Air Pollutants, Radioactive - analysis
Alaska
Atmosphere - chemistry
Radiation monitoring
Uranium - analysis
Abstract
We describe a submicron aerosol particle sampled at an altitude of 7?km near the Aleutian Islands that contained a small percentage of enriched uranium oxide. 235U was 3.1?±?0.5% of 238U. During twenty years of aircraft sampling of millions of particles in the global atmosphere, we have rarely encountered a particle with a similarly high content of 238U and never a particle with enriched 235U. The bulk of the particle consisted of material consistent with combustion of heavy fuel oil. Analysis of wind trajectories and particle dispersion model results show that the particle could have originated from a variety of areas across Asia. The source of such a particle is unclear, and the particle is described here in case it indicates a novel source where enriched uranium was dispersed.
PubMed ID
29407642 View in PubMed
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Anionic, Cationic, and Nonionic Surfactants in Atmospheric Aerosols from the Baltic Coast at Askö, Sweden: Implications for Cloud Droplet Activation.

https://arctichealth.org/en/permalink/ahliterature277406
Source
Environ Sci Technol. 2016 Mar 15;50(6):2974-82
Publication Type
Article
Date
Mar-15-2016
Author
Violaine Gérard
Barbara Nozière
Christine Baduel
Ludovic Fine
Amanda A Frossard
Ronald C Cohen
Source
Environ Sci Technol. 2016 Mar 15;50(6):2974-82
Date
Mar-15-2016
Language
English
Publication Type
Article
Keywords
Aerosols - chemistry
Anions - chemistry
Atmosphere - chemistry
Cations - chemistry
Environmental monitoring
Micelles
Surface Tension
Surface-Active Agents - chemistry
Sweden
Water - chemistry
Abstract
Recent analyses of atmospheric aerosols from different regions have demonstrated the ubiquitous presence of strong surfactants and evidenced surface tension values, s, below 40 mN m(-1), suspected to enhance the cloud-forming potential of these aerosols. In this work, this approach was further improved and combined with absolute concentration measurements of aerosol surfactants by colorimetric titration. This analysis was applied to PM2.5 aerosols collected at the Baltic station of Ask?, Sweden, from July to October 2010. Strong surfactants were found in all the sampled aerosols, with s = (32-40) ? 1 mN m(-1) and concentrations of at least 27 ? 6 mM or 104 ? 21 pmol m(-3). The absolute surface tension curves and critical micelle concentrations (CMC) determined for these aerosol surfactants show that (1) surfactants are concentrated enough in atmospheric particles to strongly depress the surface tension until activation, and (2) the surface tension does not follow the Szyszkowski equation during activation but is nearly constant and minimal, which provides new insights on cloud droplet activation. In addition, both the CMCs determined and the correlation (R(2) ~ 0.7) between aerosol surfactant concentrations and chlorophyll-a seawater concentrations suggest a marine and biological origin for these compounds.
PubMed ID
26895279 View in PubMed
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Arctic source for elevated atmospheric mercury (Hg0) in the western Bering Sea in the summer of 2013.

https://arctichealth.org/en/permalink/ahliterature294160
Source
J Environ Sci (China). 2018 Jun; 68:114-121
Publication Type
Journal Article
Date
Jun-2018
Author
V V Kalinchuk
V F Mishukov
A S Astakhov
Author Affiliation
V.I.Il'ichev Pacific Oceanological Institute of Far Eastern Branch of Russian Academy of Sciences, Vladivostok, Russia. Electronic address: viktor_kalinchuk@mail.ru.
Source
J Environ Sci (China). 2018 Jun; 68:114-121
Date
Jun-2018
Language
English
Publication Type
Journal Article
Keywords
Air Pollutants - analysis
Arctic Regions
Atmosphere - chemistry
Environmental monitoring
Mercury - analysis
Seasons
Abstract
Measurements of gaseous elemental mercury (Hg0) in the marine boundary layer of the western Bering Sea were performed using an automatic mercury analyzer RA 915+ (Ltd. "Lumex", St. Petersburg, Russia) aboard the Russian research vessel Academician M.A. Lavrentev from 3 to 20 August 2013. Hg0 concentrations varied from 0.3 to 2.1ng/m3 (n=4783); the average value (1.1±0.3ng/m3) was lower than both the background range of the Northern Hemisphere (1.5-1.7ng/m3) and average values previously observed in the Bering Sea, and corresponded to the background concentrations of the Southern Hemisphere (1.1-1.3ng/m3). Maximum Hg0 concentrations were observed within air masses that came from the lower troposphere of the central Arctic. Under these conditions, Hg0 ranged between 1.1 and 2.1ng/m3 with an average of 1.5±0.2ng/m3 (n=1183). Except for these periods, Hg0 concentrations during the rest of the study varied from 0.3 to 1.8ng/m3, with an average value of 1.0±0.2ng/m3 (n=3600). Our results support the hypothesis that, in the summer, air masses from the central Arctic Ocean can be an exporter of mercury to lower latitudes. Perhaps the atmospheric transport of elevated concentrations of Hg0 into lower latitudes may have implications for the biologic and economic health of important fisheries, such as the Bering Sea.
PubMed ID
29908730 View in PubMed
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Atmospheric deposition of mercury and methylmercury to landscapes and waterbodies of the Athabasca oil sands region.

https://arctichealth.org/en/permalink/ahliterature257559
Source
Environ Sci Technol. 2014 Jul 1;48(13):7374-83
Publication Type
Article
Date
Jul-1-2014
Author
Jane L Kirk
Derek C G Muir
Amber Gleason
Xiaowa Wang
Greg Lawson
Richard A Frank
Igor Lehnherr
Fred Wrona
Author Affiliation
Aquatic Contaminants Research Division, Environment Canada , Burlington, Ontario L7R 4A6, Canada.
Source
Environ Sci Technol. 2014 Jul 1;48(13):7374-83
Date
Jul-1-2014
Language
English
Publication Type
Article
Keywords
Alberta
Atmosphere - chemistry
Mercury - analysis
Methylmercury compounds - analysis
Oil and Gas Fields
Seasons
Silicon Dioxide - chemistry
Snow
Water Pollutants, Chemical - analysis
Water Pollution - analysis
Abstract
Atmospheric deposition of metals originating from a variety of sources, including bitumen upgrading facilities and blowing dusts from landscape disturbances, is of concern in the Athabasca oil sands region of northern Alberta, Canada. Mercury (Hg) is of particular interest as methylmercury (MeHg), a neurotoxin which bioaccumulates through foodwebs, can reach levels in fish and wildlife that may pose health risks to human consumers. We used spring-time sampling of the accumulated snowpack at sites located varying distances from the major developments to estimate winter 2012 Hg loadings to a ~20 000 km(2) area of the Athabasca oil sands region. Total Hg (THg; all forms of Hg in a sample) loads were predominantly particulate-bound (79 ± 12%) and increased with proximity to major developments, reaching up to 1000 ng m(-2). MeHg loads increased in a similar fashion, reaching up to 19 ng m(-2) and suggesting that oil sands developments are a direct source of MeHg to local landscapes and water bodies. Deposition maps, created by interpolation of measured Hg loads using geostatistical software, demonstrated that deposition resembled a bullseye pattern on the landscape, with areas of maximum THg and MeHg loadings located primarily between the Muskeg and Steepbank rivers. Snowpack concentrations of THg and MeHg were significantly correlated (r = 0.45-0.88, p
PubMed ID
24873895 View in PubMed
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Biophysical aspects of the biosphere impact on global climate.

https://arctichealth.org/en/permalink/ahliterature95912
Source
Dokl Biochem Biophys. 2002 Nov-Dec;387:338-9
Publication Type
Article
Author
Semenov D A
Khlebopros R G
Author Affiliation
Institute of Biophysics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036 Russia.
Source
Dokl Biochem Biophys. 2002 Nov-Dec;387:338-9
Language
English
Publication Type
Article
Keywords
Atmosphere - chemistry
Biophysical Phenomena
Biophysics
Carbon Monoxide - chemistry
Climate
Greenhouse Effect
Kinetics
Models, Theoretical
Temperature
PubMed ID
12577617 View in PubMed
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66 records – page 1 of 7.