Show simple item record

dc.contributor.authorDastoor, A.P.
dc.contributor.authorDavignon, D.
dc.contributor.authorTheys, N.
dc.contributor.authorVan Roozendael, M.
dc.contributor.authorSteffen, A.
dc.contributor.authorAriya, P.A.
dc.date2008
dc.date.accessioned2016-09-21T12:08:06Z
dc.date.available2016-09-21T12:08:06Z
dc.identifier.urihttps://orfeo.belnet.be/handle/internal/4351
dc.descriptionAt polar sunrise, gaseous elemental mercury (GEM) undergoes an exceptional dynamic exchange in the air and at the snow surface during which GEM can be rapidly removed fromthe atmosphere (the so-called atmospheric mercury depletion events (AMDEs)) as well as re-emitted from the snow within a few hours to days in the Polar Regions. Although high concentrations of total mercury in snow following AMDEs is well documented, there is very little data available on the redox transformation processes of mercury in the snow and the fluxes of mercury at the air/snow interface. Therefore, the net gain of mercury in the Polar Regions as a result of AMDEs is still an open question. We developed a new version of the global mercury model, GRAHM, which includes for the first time bidirectional surface exchange of GEM in Polar Regions in spring and summer by developing schemes for mercury halogen oxidation, deposition, and re-emission. Also for the first time, GOME satellite data-derived boundary layer concentrations of BrO have been used in a global mercury model for representation of halogen mercury chemistry. Comparison of model simulated and measured atmospheric concentrations of GEM at Alert, Canada, for 3 years (2002-2004) shows the model's capability in simulating the rapid cycling of mercury during and after AMDEs. Brooks et al. (1) measured mercury deposition, re-emission, and net surface gain fluxes of mercury at Barrow, AK, during an intensive measurement campaign for a 2 week period in spring (March 25 to April 7, 2003). They reported 1.7, 1.0 ± 0.2, and 0.7 ± 0.2 μg m -2 deposition, re-emission, and net surface gain, respectively. Using the optimal configuration of the model, we estimated 1.8 μg m-2 deposition, 1.0 μg m-2 re-emission, and 0.8 μg m-2 net surface gain of mercury for the same time period at Barrow. The estimated net annual accumulation of mercury within the Arctic Circle north of 66.5° is ∼1741 with ±7 t of interannual variability for 2002-2004 using the optimal configuration. We estimated the uncertainty of the model results to the Hg/Br reaction rate coefficient to be ∼6%. Springtime is clearly demonstrated as the most active period of mercury exchanges and net surface gain (∼46% of annual accumulation) in the Arctic.
dc.languageeng
dc.titleModeling dynamic exchange of gaseous elemental mercury at polar sunrise
dc.typeArticle
dc.subject.frascatiPhysical sciences
dc.audienceScientific
dc.subject.freeAtmospheric chemistry
dc.subject.freeAtmospherics
dc.subject.freeElectron multipliers
dc.subject.freeGems
dc.subject.freePrecipitation (meteorology)
dc.subject.freeSprings (components)
dc.subject.freeAtmospheric concentrations
dc.subject.freeAtmospheric mercury
dc.subject.freeGaseous elemental mercury (GEM)
dc.subject.freeH igh concentrations
dc.subject.freeMercury chemistry
dc.subject.freeMercury depositions
dc.subject.freeMercury(III)
dc.subject.freeNet gain
dc.subject.freePolar Regions
dc.subject.freeRapid cycling
dc.subject.freeRe-emission
dc.subject.freeRedox transformations
dc.subject.freeSatellite data
dc.subject.freeSurface exchanges
dc.subject.freeTotal mercury (Thg)
dc.subject.freeMercury (metal)
dc.subject.freebromine derivative
dc.subject.freehalogen
dc.subject.freemercury
dc.subject.freesnow
dc.subject.freeatmospheric modeling
dc.subject.freeflux measurement
dc.subject.freegas exchange
dc.subject.freemercury (element)
dc.subject.freeoxidation
dc.subject.freepolar region
dc.subject.freesatellite data
dc.subject.freeair
dc.subject.freeArctic
dc.subject.freearticle
dc.subject.freeatmospheric deposition
dc.subject.freeatmospheric dispersion
dc.subject.freemodel
dc.subject.freeoxidation
dc.subject.freeoxidation reduction reaction
dc.subject.freespring
dc.subject.freesummer
dc.subject.freeAir Pollutants
dc.subject.freeArctic Regions
dc.subject.freeMercury
dc.subject.freePeriodicity
dc.subject.freeSeasons
dc.subject.freeSnow
dc.subject.freeSunlight
dc.subject.freeArctic
dc.source.titleEnvironmental Science and Technology
dc.source.volume42
dc.source.issue14
dc.source.page5183-5188
Orfeo.peerreviewedNo
dc.identifier.doi10.1021/es800291w
dc.identifier.scopus2-s2.0-48249124514


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record