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Venugopal AU, Bertler NAN, Severinghaus JP, Brook EJ, Cortese G, Lee JE, Blunier T, Mayewski PA, Kjær HA, Carter L, Weber ME, Levy RH, Pyne RL, Vandergoes MJ. Antarctic evidence for an abrupt northward shift of the Southern Hemisphere westerlies at 32 ka BP. Nat Commun 2023; 14:5432. [PMID: 37669925 PMCID: PMC10480229 DOI: 10.1038/s41467-023-40951-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 08/16/2023] [Indexed: 09/07/2023] Open
Abstract
High-resolution ice core records from coastal Antarctica are particularly useful to inform our understanding of environmental changes and their drivers. Here, we present a decadally resolved record of sea-salt sodium (a proxy for open-ocean area) and non-sea salt calcium (a proxy for continental dust) from the well-dated Roosevelt Island Climate Evolution (RICE) core, focusing on the time period between 40-26 ka BP. The RICE dust record exhibits an abrupt shift towards a higher mean dust concentration at 32 ka BP. Investigating existing ice-core records, we find this shift is a prominent feature across Antarctica. We propose that this shift is linked to an equatorward displacement of Southern Hemisphere westerly winds. Subsequent to the wind shift, data suggest a weakening of Southern Ocean upwelling and a decline of atmospheric CO2 to lower glacial values, hence making this shift an important glacial climate event with potentially important insights for future projections.
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Affiliation(s)
- Abhijith U Venugopal
- GNS Science, Lower Hutt, 5010, New Zealand.
- Antarctic Research Centre, Victoria University of Wellington, Wellington, 6012, New Zealand.
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, 8041, New Zealand.
| | - Nancy A N Bertler
- GNS Science, Lower Hutt, 5010, New Zealand
- Antarctic Research Centre, Victoria University of Wellington, Wellington, 6012, New Zealand
| | | | - Edward J Brook
- College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR, 97330, USA
| | | | - James E Lee
- College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR, 97330, USA
| | - Thomas Blunier
- Physics of Ice, Climate and Earth, Niels Bohr Institute, University of Copenhagen, Juliana Maries Vej 30, 2100, Copenhagen, Denmark
| | - Paul A Mayewski
- Climate Change Institute, University of Maine, Orono, ME, 04469-5790, USA
| | - Helle A Kjær
- Physics of Ice, Climate and Earth, Niels Bohr Institute, University of Copenhagen, Juliana Maries Vej 30, 2100, Copenhagen, Denmark
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, TAS, 7004, Australia
| | - Lionel Carter
- Antarctic Research Centre, Victoria University of Wellington, Wellington, 6012, New Zealand
| | - Michael E Weber
- Insitute for Geosciences, Department of Geochemistry and Petrology, University of Bonn, Bonn, 53115, Germany
| | - Richard H Levy
- GNS Science, Lower Hutt, 5010, New Zealand
- Antarctic Research Centre, Victoria University of Wellington, Wellington, 6012, New Zealand
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Abstract
Both inorganic and organic complexation of metal cations in clouds or rainwater is essential to describe the global biogeochemical cycles of metals, because complexation can increase metal solubility and stabilize some of their oxidation states. Within a Project of the National Research Program in the Antarctica, atmospheric depositions were collected during the Antarctic summer 2017–2018 in eight sampling sites. The main ionic components occurring in water extracts of these atmospheric depositions were quantified, and a chemical model was applied, in order to identify the main species occurring in the samples. The speciation study showed that most cations were present as aquoions, except for Fe, which occurred predominantly in hydrolytic forms. The model allowed us to foresee the effect of an increase in the concentration levels of all the solution components, by simulating what could happen when the original particles act as cloud condensation nuclei. The role of inorganic anions as complexing agents becomes important when increasing total concentrations of all the solutes by a factor >100 compared to the water extracts, while the presence of organic acids acquires significance for samples having organic acid concentration higher than 10−5 mol L−1. Moreover, it was possible to pinpoint the formation constants that mostly affect the chemical system, and to gain insight into the behavior of metals in wet depositions, which is fundamental knowledge in atmospheric photochemistry studies and in the modeling of the biogeochemical cycles of metal cations.
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Ding Q, Li C, Wang H, Xu C, Kuang H. Electrochemical detection of heavy metal ions in water. Chem Commun (Camb) 2021; 57:7215-7231. [PMID: 34223844 DOI: 10.1039/d1cc00983d] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Heavy metal ions are one of the main sources of water pollution. Most heavy metal ions are carcinogens that pose a threat to both ecological balance and human health. With the increasing demand for heavy metal detection, electrochemical detection is favorable due to its high sensitivity and efficiency. Here, after discussing the pollution sources and toxicities of Hg(ii), Cd(ii), As(iii), Pb(ii), UO2(ii), Tl(i), Cr(vi), Ag(i), and Cu(ii), we review a variety of recent electrochemical methods for detecting heavy metal ions. Compared with traditional methods, electrochemical methods are portable, fast, and cost-effective, and they can be adapted to various on-site inspection sites. Our review shows that the electrochemical detection of heavy metal ions is a very promising strategy that has attracted widespread attention and can be applied in agriculture, life science, clinical diagnosis, and analysis.
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Affiliation(s)
- Qi Ding
- The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China.
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