Estimating the recharge properties of the deep ocean using noble gases and helium isotopes
The distribution of noble gases and helium isotopes in the dense shelf waters of Antarctica reflect the boundary conditions nearthe ocean surface: air-sea exchange, sea ice formation and subsurface ice melt. We use a non-linear least-squares solution to determine the value of the recharge tempera...
| Main Authors: | , , , , , , , , , |
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| Format: | Journal article |
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Wiley
2016
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| _version_ | 1797105071982379008 |
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| author | Loose, B Jenkins, W Moriarty, R Brown, P Jullion, L Garabato, A Valdes, S Hoppema, M Ballentine, C Meredith, M |
| author_facet | Loose, B Jenkins, W Moriarty, R Brown, P Jullion, L Garabato, A Valdes, S Hoppema, M Ballentine, C Meredith, M |
| author_sort | Loose, B |
| collection | OXFORD |
| description | The distribution of noble gases and helium isotopes in the dense shelf waters of Antarctica reflect the boundary conditions nearthe ocean surface: air-sea exchange, sea ice formation and subsurface ice melt. We use a non-linear least-squares solution to determine the value of the recharge temperature and salinity, as well as the excess air injection and glacial meltwater content throughout the water column and in the precursor to Antarctic Bottom Water. The noble gas-derived recharge temperature and salinity in the Weddell Gyre are -1.95 °C and 34.95 psu near 5500 m; these cold, salty recharge values are a result of surface cooling as well as brine rejection during sea ice formation in Antarctic polynyas. In comparison, the global value for deep water recharge temperature is -0.44 °C at 5500 m, which is 1.5 °C warmer than the southern hemisphere deep water recharge temperature, reflectingthe contribution from the north Atlantic. The contrast between northern and southern hemisphere recharge properties highlight the impact of sea ice formation on setting the gas properties in southern sourced deep water. Below 1000 m, glacial meltwater averages 3.5 ‰ by volume and represents greater than 50% of the excess neon and argon found in the water column. These results indicate glacial melt has a non-negligible impact on the atmospheric gas content of Antarctic Bottom Water. |
| first_indexed | 2024-03-07T06:42:17Z |
| format | Journal article |
| id | oxford-uuid:f9b61078-cb5a-463b-a9d5-8f08af5333b4 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T06:42:17Z |
| publishDate | 2016 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:f9b61078-cb5a-463b-a9d5-8f08af5333b42022-03-27T12:59:54ZEstimating the recharge properties of the deep ocean using noble gases and helium isotopesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f9b61078-cb5a-463b-a9d5-8f08af5333b4Symplectic Elements at OxfordWiley2016Loose, BJenkins, WMoriarty, RBrown, PJullion, LGarabato, AValdes, SHoppema, MBallentine, CMeredith, MThe distribution of noble gases and helium isotopes in the dense shelf waters of Antarctica reflect the boundary conditions nearthe ocean surface: air-sea exchange, sea ice formation and subsurface ice melt. We use a non-linear least-squares solution to determine the value of the recharge temperature and salinity, as well as the excess air injection and glacial meltwater content throughout the water column and in the precursor to Antarctic Bottom Water. The noble gas-derived recharge temperature and salinity in the Weddell Gyre are -1.95 °C and 34.95 psu near 5500 m; these cold, salty recharge values are a result of surface cooling as well as brine rejection during sea ice formation in Antarctic polynyas. In comparison, the global value for deep water recharge temperature is -0.44 °C at 5500 m, which is 1.5 °C warmer than the southern hemisphere deep water recharge temperature, reflectingthe contribution from the north Atlantic. The contrast between northern and southern hemisphere recharge properties highlight the impact of sea ice formation on setting the gas properties in southern sourced deep water. Below 1000 m, glacial meltwater averages 3.5 ‰ by volume and represents greater than 50% of the excess neon and argon found in the water column. These results indicate glacial melt has a non-negligible impact on the atmospheric gas content of Antarctic Bottom Water. |
| spellingShingle | Loose, B Jenkins, W Moriarty, R Brown, P Jullion, L Garabato, A Valdes, S Hoppema, M Ballentine, C Meredith, M Estimating the recharge properties of the deep ocean using noble gases and helium isotopes |
| title | Estimating the recharge properties of the deep ocean using noble gases and helium isotopes |
| title_full | Estimating the recharge properties of the deep ocean using noble gases and helium isotopes |
| title_fullStr | Estimating the recharge properties of the deep ocean using noble gases and helium isotopes |
| title_full_unstemmed | Estimating the recharge properties of the deep ocean using noble gases and helium isotopes |
| title_short | Estimating the recharge properties of the deep ocean using noble gases and helium isotopes |
| title_sort | estimating the recharge properties of the deep ocean using noble gases and helium isotopes |
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