@article{fractionation:458,
      recid = {458},
      author = {Archer, David},
      title = {A model of mercury cycling and isotopic fractionation in  the ocean},
      address = {2018},
      abstract = {Mercury speciation and isotopic fractionation processes  have been incorporated into the HAMOCC offline ocean tracer  advection code.  The model is fast enough to allow a wide  exploration of the sensitivity of the Hg cycle in the  oceans, and of factors controlling human exposure to  monomethyl-Hg through the consumption of fish.  Vertical  particle transport of Hg appears to play a discernable role  in setting present-day Hg distributions, which we surmise  by the fact that in simulations without particle transport,  the high present-day Hg deposition rate leads to an Hg  maximum at the sea surface, rather than a subsurface  maximum as observed.  Hg particle transport has a  relatively small impact on anthropogenic Hg uptake, but it  sequesters Hg deeper in the water column, so that excess Hg  is retained in the model ocean for a longer period of time  after anthropogenic Hg deposition is stopped.  Among 10  rate constants in the model, steady state Hg concentrations  are most sensitive to reactions that are sources or sinks  of Hg(0), the evasion of which to the atmosphere is the  dominant sink term in the surface ocean. Isotopic  fractionations in the interconversion reactions are most  strongly expressed, in the isotopic signatures of dissolved  Hg, in reactions that involve the dominant dissolved  species, Hg(II), including mass independent fractionation  during Hg photoreduction.  The Δ199Hg of MMHg in the model,  subject to photoreduction fractionation, reproduces the  Δ199Hg of fish in the upper 1000 m of the ocean, while the  impact of anthropogenic Hg deposition on Hg isotope ratios  is essentially negligible.},
      url = {http://knowledge.uchicago.edu/record/458},
}