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Antiphased dust deposition and productivity in the Antarctic Zone over 1.5 million years. Nat Commun 2022; 13:2044. [PMID: 35440628 PMCID: PMC9018689 DOI: 10.1038/s41467-022-29642-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 03/25/2022] [Indexed: 11/08/2022] Open
Abstract
The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report a high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-ocean records cover the last 1.5 Ma, thus doubling that from Antarctic ice-cores. We find a 5 to 15-fold increase in dust deposition during glacials and a 2 to 5-fold increase in biogenic silica deposition, reflecting higher ocean productivity during interglacials. This antiphasing persisted throughout the last 25 glacial cycles. Dust deposition became more pronounced across the Mid-Pleistocene Transition (MPT) in the Southern Hemisphere, with an abrupt shift suggesting more severe glaciations since ~0.9 Ma. Productivity was intermediate pre-MPT, lowest during the MPT and highest since 0.4 Ma. Generally, glacials experienced extended sea-ice cover, reduced bottom-water export and Weddell Gyre dynamics, which helped lower atmospheric CO2 levels.
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Liu K, Hou S, Wu S, Zhang W, Zou X, Yu J, Song J, Sun X, Huang R, Pang H, Wang J. Assessment of heavy metal contamination in the atmospheric deposition during 1950-2016 A.D. from a snow pit at Dome A, East Antarctica. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 268:115848. [PMID: 33096389 DOI: 10.1016/j.envpol.2020.115848] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 10/12/2020] [Accepted: 10/12/2020] [Indexed: 06/11/2023]
Abstract
Antarctic trace element records could provide important insights into the impact of human activities on the environment over the past few centuries. In this study, we investigated the atmospheric concentrations of 14 representative heavy metals (Al, As, Cd, Co, Cu, Fe, K, Mg, Mn, Pb, Sb, Sr, Tl and V) from 174 samples collected in a 4-m snow pit at Dome Argus (Dome A) on the East Antarctic Plateau, covering the period from 1950 to 2016 A.D. We found great variability in the annual concentration of all metals. The crustal enrichment factors suggest that the concentrations of some heavy metals (Cd, Sb, Cu, As and Pb) were likely influenced by anthropogenic activities in recent decades. An analysis of source regions suggests that heavy metal pollution at Dome A was largely caused by human activities in Australia and South America (e.g. mining production, leaded gasoline). Based on the relationship between the trace elements fluxes and sea ice concentration (SIC), sea surface temperature (SST) and annual mean air temperature at 2 m above the ground (T2m), our analysis shows that deposition and transport of atmospheric aerosol at Dome A were influenced by circum-Antarctic atmospheric circulations.
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Affiliation(s)
- Ke Liu
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China; Ministry of Education Key Laboratory for Coastal and Island Development, Nanjing University, Nanjing, 210023, China
| | - Shugui Hou
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China; Ministry of Education Key Laboratory for Coastal and Island Development, Nanjing University, Nanjing, 210023, China.
| | - Shuangye Wu
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China; Department of Geology, University of Dayton, Dayton, OH, 45469, USA
| | - Wangbin Zhang
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China; Ministry of Education Key Laboratory for Coastal and Island Development, Nanjing University, Nanjing, 210023, China
| | - Xiang Zou
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China; Ministry of Education Key Laboratory for Coastal and Island Development, Nanjing University, Nanjing, 210023, China
| | - Jinhai Yu
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China
| | - Jing Song
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China
| | - Xuechun Sun
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China
| | - Renhui Huang
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China
| | - Hongxi Pang
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China; Ministry of Education Key Laboratory for Coastal and Island Development, Nanjing University, Nanjing, 210023, China
| | - Jiajia Wang
- School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China
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Kanitz T, Ansmann A, Engelmann R, Althausen D. North-south cross sections of the vertical aerosol distribution over the Atlantic Ocean from multiwavelength Raman/polarization lidar during Polarstern cruises. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2013; 118:2643-2655. [PMID: 25821662 PMCID: PMC4370761 DOI: 10.1002/jgrd.50273] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 02/01/2013] [Accepted: 02/12/2013] [Indexed: 06/04/2023]
Abstract
Shipborne aerosol lidar observations were performed aboard the research vessel Polarstern in 2009 and 2010 during three north-south cruises from about 50°N to 50°S. The aerosol data set provides an excellent opportunity to characterize and contrast the vertical aerosol distribution over the Atlantic Ocean in the polluted northern and relatively clean southern hemisphere. Three case studies, an observed pure Saharan dust plume, a Patagonian dust plume east of South America, and a case of a mixed dust/smoke plume west of Central Africa are exemplarily shown and discussed by means of their optical properties. The meridional transatlantic cruises were used to determine the latitudinal cross section of the aerosol optical thickness (AOT). Profiles of particle backscatter and extinction coefficients are presented as mean profiles for latitudinal belts to contrast northern- and southern-hemispheric aerosol loads and optical effects. Results of lidar observations at Punta Arenas (53°S), Chile, and Stellenbosch (34°S), South Africa, are shown and confirm the lower frequency of occurrence of free-tropospheric aerosol in the southern hemisphere than in the northern hemisphere. The maximum latitudinal mean AOT of 0.27 was found in the northern tropics (0- 15°N) in the Saharan outflow region. Marine AOT is typically 0.05 ± 0.03. Particle optical properties are presented separately for the marine boundary layer and the free troposphere. Concerning the contrast between the anthropogenically influenced midlatitudinal aerosol conditions in the 30- 60°N belt and the respective belt in the southern hemisphere over the remote Atlantic, it is found that the AOT and extinction coefficients for the vertical column from 0-5km (total aerosol column) and 1-5km height (lofted aerosol above the marine boundary layer) are a factor of 1.6 and 2 higher at northern midlatitudes than at respective southern midlatitudes, and a factor of 2.5 higher than at the clean marine southern-hemispheric site of Punta Arenas. The strong contrast is confined to the lowermost 3km of the atmosphere.
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Affiliation(s)
- T Kanitz
- Leibniz Institute for Tropospheric Research Leipzig, Germany
| | - A Ansmann
- Leibniz Institute for Tropospheric Research Leipzig, Germany
| | - R Engelmann
- Leibniz Institute for Tropospheric Research Leipzig, Germany
| | - D Althausen
- Leibniz Institute for Tropospheric Research Leipzig, Germany
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Lin M, Fiore AM, Horowitz LW, Cooper OR, Naik V, Holloway J, Johnson BJ, Middlebrook AM, Oltmans SJ, Pollack IB, Ryerson TB, Warner JX, Wiedinmyer C, Wilson J, Wyman B. Transport of Asian ozone pollution into surface air over the western United States in spring. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016961] [Citation(s) in RCA: 201] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Li F, Ramaswamy V, Ginoux P, Broccoli AJ, Delworth T, Zeng F. Toward understanding the dust deposition in Antarctica during the Last Glacial Maximum: Sensitivity studies on plausible causes. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd014791] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fuyu Li
- Program in Atmospheric and Oceanic Sciences; Princeton University; Princeton New Jersey USA
| | - V. Ramaswamy
- Geophysical Fluid Dynamics Laboratory; NOAA; Princeton New Jersey USA
| | - Paul Ginoux
- Geophysical Fluid Dynamics Laboratory; NOAA; Princeton New Jersey USA
| | - Anthony J. Broccoli
- Center for Environmental Prediction and Department of Environmental Sciences; Rutgers University; New Brunswick New Jersey USA
| | - Thomas Delworth
- Geophysical Fluid Dynamics Laboratory; NOAA; Princeton New Jersey USA
| | - Fanrong Zeng
- Geophysical Fluid Dynamics Laboratory; NOAA; Princeton New Jersey USA
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