Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study
Distinct diurnal and seasonal variations of mercury (Hg) have been observed in near-surface air at Concordia Station on the East Antarctic Plateau, but the processes controlling these characteristics are not well understood. Here, we use a box model to interpret the Hg0 (gaseous elemental mercury) m...
| Main Authors: | , , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Published: |
Copernicus Publications
2019
|
| Online Access: | http://hdl.handle.net/1721.1/120548 https://orcid.org/0000-0001-6395-7422 https://orcid.org/0000-0002-6396-5622 |
| _version_ | 1811085395050364928 |
|---|---|
| author | Gallée, Hubert Sprovieri, Francesca Pirrone, Nicola Helmig, Detlev Savarino, Joël Magand, Olivier Dommergue, Aurélien Song, Shaojie Angot, Helene Paule Selin, Noelle E |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Gallée, Hubert Sprovieri, Francesca Pirrone, Nicola Helmig, Detlev Savarino, Joël Magand, Olivier Dommergue, Aurélien Song, Shaojie Angot, Helene Paule Selin, Noelle E |
| author_sort | Gallée, Hubert |
| collection | MIT |
| description | Distinct diurnal and seasonal variations of mercury (Hg) have been observed in near-surface air at Concordia Station on the East Antarctic Plateau, but the processes controlling these characteristics are not well understood. Here, we use a box model to interpret the Hg0 (gaseous elemental mercury) measurements in thes year 2013. The model includes atmospheric Hg0 oxidation (by OH, O3, or bromine), surface snow HgII (oxidized mercury) reduction, and air-snow exchange, and is driven by meteorological fields from a regional climate model. The simulations suggest that a photochemically driven mercury diurnal cycle occurs at the air-snow interface in austral summer. The fast oxidation of Hg0 in summer may be provided by a two-step bromine-initiated scheme, which is favored by low temperature and high nitrogen oxides at Concordia. The summertime diurnal variations of Hg0 (peaking during daytime) may be confined within several tens of meters above the snow surface and affected by changing mixed layer depths. Snow re-emission of Hg0 is mainly driven by photoreduction of snow HgII in summer. Intermittent warming events and a hypothesized reduction of HgII occurring in snow in the dark may be important processes controlling the mercury variations in the non-summer period, although their relative importance is uncertain. The Br-initiated oxidation of Hg0 is expected to be slower at Summit Station in Greenland than at Concordia (due to their difference in temperature and levels of nitrogen oxides and ozone), which may contribute to the observed differences in the summertime diurnal variations of Hg0 between these two polar inland stations. |
| first_indexed | 2024-09-23T13:08:54Z |
| format | Article |
| id | mit-1721.1/120548 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T13:08:54Z |
| publishDate | 2019 |
| publisher | Copernicus Publications |
| record_format | dspace |
| spelling | mit-1721.1/1205482022-10-01T13:20:57Z Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study Gallée, Hubert Sprovieri, Francesca Pirrone, Nicola Helmig, Detlev Savarino, Joël Magand, Olivier Dommergue, Aurélien Song, Shaojie Angot, Helene Paule Selin, Noelle E Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology. Institute for Data, Systems, and Society Song, Shaojie Angot, Helene Paule Selin, Noelle E Distinct diurnal and seasonal variations of mercury (Hg) have been observed in near-surface air at Concordia Station on the East Antarctic Plateau, but the processes controlling these characteristics are not well understood. Here, we use a box model to interpret the Hg0 (gaseous elemental mercury) measurements in thes year 2013. The model includes atmospheric Hg0 oxidation (by OH, O3, or bromine), surface snow HgII (oxidized mercury) reduction, and air-snow exchange, and is driven by meteorological fields from a regional climate model. The simulations suggest that a photochemically driven mercury diurnal cycle occurs at the air-snow interface in austral summer. The fast oxidation of Hg0 in summer may be provided by a two-step bromine-initiated scheme, which is favored by low temperature and high nitrogen oxides at Concordia. The summertime diurnal variations of Hg0 (peaking during daytime) may be confined within several tens of meters above the snow surface and affected by changing mixed layer depths. Snow re-emission of Hg0 is mainly driven by photoreduction of snow HgII in summer. Intermittent warming events and a hypothesized reduction of HgII occurring in snow in the dark may be important processes controlling the mercury variations in the non-summer period, although their relative importance is uncertain. The Br-initiated oxidation of Hg0 is expected to be slower at Summit Station in Greenland than at Concordia (due to their difference in temperature and levels of nitrogen oxides and ozone), which may contribute to the observed differences in the summertime diurnal variations of Hg0 between these two polar inland stations. National Science Foundation (U.S.) (Grant ACP-1053648) 2019-02-26T20:16:49Z 2019-02-26T20:16:49Z 2018-11 2018-09 2019-02-25T12:36:32Z Article http://purl.org/eprint/type/JournalArticle 1680-7324 1680-7316 http://hdl.handle.net/1721.1/120548 Song, Shaojie et al. “Understanding Mercury Oxidation and Air–snow Exchange on the East Antarctic Plateau: a Modeling Study.” Atmospheric Chemistry and Physics 18, 21 (November 2018): 15825–15840 © 2018 Author(s) https://orcid.org/0000-0001-6395-7422 https://orcid.org/0000-0002-6396-5622 http://dx.doi.org/10.5194/acp-18-15825-2018 Atmospheric Chemistry and Physics Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf Copernicus Publications Copernicus |
| spellingShingle | Gallée, Hubert Sprovieri, Francesca Pirrone, Nicola Helmig, Detlev Savarino, Joël Magand, Olivier Dommergue, Aurélien Song, Shaojie Angot, Helene Paule Selin, Noelle E Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study |
| title | Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study |
| title_full | Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study |
| title_fullStr | Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study |
| title_full_unstemmed | Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study |
| title_short | Understanding mercury oxidation and air–snow exchange on the East Antarctic Plateau: a modeling study |
| title_sort | understanding mercury oxidation and air snow exchange on the east antarctic plateau a modeling study |
| url | http://hdl.handle.net/1721.1/120548 https://orcid.org/0000-0001-6395-7422 https://orcid.org/0000-0002-6396-5622 |
| work_keys_str_mv | AT galleehubert understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT sprovierifrancesca understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT pirronenicola understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT helmigdetlev understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT savarinojoel understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT magandolivier understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT dommergueaurelien understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT songshaojie understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT angothelenepaule understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy AT selinnoellee understandingmercuryoxidationandairsnowexchangeontheeastantarcticplateauamodelingstudy |