The Monitoring and Modelling of Hg Species in Support of Local, Regional and Global Modelling

Landis, Matthew S.; Lynam, Mary M.; Stevens, Robert K.

doi:10.1007/0-387-24494-8_7

Cited by 22 publications

(21 citation statements)

References 59 publications

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“…These findings are probably due to large natural sources of Hg not accounted for and/or underestimated Hg emissions. The first reported data on Hg-species performed at high altitude are from Mauna Loa, (Hawaii Monitoring Site, Landis et al, 2005) and Mt. Bachelor, (Oregon, USA, Swartzendruber et al, 2006).…”

Section: Mercury Measurements At Altitude (Including Aircraft)mentioning

confidence: 99%

A review of worldwide atmospheric mercury measurements

Sprovieri

Pirrone

Ebinghaus³

et al. 2010

Atmos. Chem. Phys.

228

172

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Abstract.A large number of activities have been carried out to characterise the levels of mercury (Hg) species in ambient air and precipitation, in order to understand how they vary over time and how they depend on meteorological conditions. Following the discovery of atmospheric Hg depletion events (AMDEs) in Polar Regions, a significant research effort was made to assess the chemical-physical mechanisms behind the rapid conversion of atmospheric gaseous Hg (Hg 0 ) into reactive and water-soluble forms which are potentially bioavailable. The understanding of the way in which Hg is released into the atmosphere, transformed, deposited and eventually incorporated into biota is of crucial importance not only for the polar regions but also for the marine environment in general. The oceans and seas are both sources and sinks of Hg and play a major role in the Hg cycle. In this work, the available Hg concentration datasets from a number of terrestrial sites (industrial, rural and remote) in both the Northern and Southern Hemispheres as well as over oceans and seas have been investigated. The higher Hg species concentration and variability observed in the Northern Hemisphere suggest that the majority of emissions and re-emissions occur there. The inter-hemispherical gradient with higher total gaseous mercury (TGM) concentrations in the Northern Hemisphere has remained nearly constant over the years for which data are available. The analysis of Hg concentration patterns indicates the differences in regional source/sink characteristics, with increasing variability toward areas strongly influenced by anthropogenic sources. The large increase in Hg emissions in rapidly developing countries (i.e., China, India) over the last decade, due primar-ily to a sharp increase in energy production from coal combustion, are not currently reflected in the long-term measurements of TGM in ambient air and precipitation at continuous monitoring sites in either Northern Europe or North America. The discrepancy between observed gaseous Hg concentrations (steady or decreasing) and global Hg emission inventories (increasing) has not yet been explained, though the potential oxidation of the atmosphere during the last decade is increasing. Currently, however, a coordinated observational network for Hg does not exist.

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Section: Mercury Measurements At Altitude (Including Aircraft)mentioning

confidence: 99%

A review of worldwide atmospheric mercury measurements

Sprovieri

Pirrone

Ebinghaus³

et al. 2010

Atmos. Chem. Phys.

228

172

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“…Recent mass spectrometer measurements near the tropopause have discovered mercury associated with particles and have suggested that large fraction of the mercury in the lower stratosphere may be in the particulate fraction [Murphy et al, 2006]. Preliminary reports from measurements at the Mauna Loa Observatory and airborne measurements in Florida [Landis et al, 2005] have suggested that there are elevated levels of RGM and PHg in the free troposphere.…”

Section: Introductionmentioning

confidence: 99%

Observations of reactive gaseous mercury in the free troposphere at the Mount Bachelor Observatory

Swartzendruber

Jaffe

Prestbo³

et al. 2006

J. Geophys. Res.

172

176

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[1] We measured gaseous elemental mercury (GEM), particulate mercury (PHg), and reactive gaseous mercury (RGM), along with CO, ozone, and aerosol scatter at the Mount Bachelor Observatory (2.7 km above sea level), Oregon, from May to August 2005. The mean mercury concentrations (at standard conditions) were 1.54 ng/m 3 (GEM), 5.2 pg/m 3 (PHg), and 43 pg/m 3 (RGM). RGM enhancements, up to 600 pg/m 3 , occurred at night and were linked to a diurnal pattern of upslope and downslope flows that mixed in boundary layer air during the day and free tropospheric air at night. During the night, RGM was inversely correlated (P < 0.0001) with CO (r = À0.36), GEM (r = À0.73), and H 2 O (r = À0.44), was positively correlated with ozone (r = 0.38), and could not be linked to recent anthropogenic emissions from local sources or long-range transport. Principal component analysis and a composite of change in RGM versus change in GEM during RGM enhancements indicate that a nearly quantitative shift in speciation is associated with increases in ozone and decreases in water vapor and CO. This argues that high concentrations of RGM are present in the free troposphere because of in situ oxidation of GEM to RGM. A global chemical transport model reproduces the RGM mean and diurnal pattern but underestimates the magnitude of the largest observed enhancements. Since the only modeled, in situ RGM production mechanisms are oxidation of GEM by ozone and OH, this implies that there are faster reaction rates or additional RGM production mechanisms in the free troposphere.

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“…This implies that Hg(II) formed in situ was unable to condense to particles under these dry air conditions. Both these studies ( [140,143] found very similar observations pointing out that the high Hg(II) concentrations observed, first in Hawaii and later in Oregon were due to atmospheric oxidation and not related to pollution events. Similar results have been obtained in Colorado at the Storm Peak Laboratory high altitude research station (3220 m asl) by Faïn et al [7].…”

Section: Mercury Measurements At High Altitude Locations (Including Amentioning

confidence: 54%

“…Currently, there are a number of high elevation sites including Mt. Bachelor in the western USA [139], Mauna Loa in Hawaii [140], Wank Mt. in Germany [141], and the Lulin station in Taiwan [142].…”

Section: Mercury Measurements At High Altitude Locations (Including Amentioning

confidence: 99%

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Overview of major processes and mechanisms affecting the mercury cycle on different spatial and temporal scales

Pirrone

Hedgecock

Cinnirella

et al. 2010

EPJ Web of Conferences

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Abstract. Mercury emissions to the atmosphere and its transport, transformation and deposition to and re-emission from terrestrial and aquatic ecosystems on hemispherical and global scales has received increasing attention from both the scientific and the regulatory communities during the last twenty years. It is well known that the atmosphere is the major transport media through which mercury is redistributed on global scale once it is released from point and diffuse emission sources. A substantial amount of research has been carried out worldwide aiming to assess the relationships between emissions from natural vs. anthropogenic sources, inter-hemispherical atmospheric transport patterns, and atmospheric deposition to and re-emission from oceans, its bioaccumulation in fish, and evaluation of policy strategies to reduce the impact of mercury emissions on human health and ecosystems. This chapter provides a highlight of key aspects related to mercury contamination, including: a) major processes affecting the mercury cycle between the atmosphere and aquatic and terrestrial ecosystems, b) mercury emissions from natural and anthropogenic sources, c) spatial and temporal distributions and trends of mercury species over the northern and southern hemispheres, d) the chemical and physical processes affecting the transport and fate of atmospheric mercury, and e)major policy frameworks aiming to control the impact of mercury on human health and ecosystems.

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The Monitoring and Modelling of Hg Species in Support of Local, Regional and Global Modelling

Cited by 22 publications

References 59 publications

A review of worldwide atmospheric mercury measurements

A review of worldwide atmospheric mercury measurements

Observations of reactive gaseous mercury in the free troposphere at the Mount Bachelor Observatory

Overview of major processes and mechanisms affecting the mercury cycle on different spatial and temporal scales

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