Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014
We present 60 years of Δ 14 CO 2 measurements from Wellington, New Zealand (41° S, 175° E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest direct atmospheric Δ...
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ftdoajarticles:oai:doaj.org/article:744dcbbb084b428c934a184ccedf8785 2023-05-15T18:25:22+02:00 Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014 J. C. Turnbull S. E. Mikaloff Fletcher I. Ansell G. W. Brailsford R. C. Moss M. W. Norris K. Steinkamp 2017-12-01T00:00:00Z https://doi.org/10.5194/acp-17-14771-2017 https://doaj.org/article/744dcbbb084b428c934a184ccedf8785 EN eng Copernicus Publications https://www.atmos-chem-phys.net/17/14771/2017/acp-17-14771-2017.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-17-14771-2017 1680-7316 1680-7324 https://doaj.org/article/744dcbbb084b428c934a184ccedf8785 Atmospheric Chemistry and Physics, Vol 17, Pp 14771-14784 (2017) Physics QC1-999 Chemistry QD1-999 article 2017 ftdoajarticles https://doi.org/10.5194/acp-17-14771-2017 2022-12-30T20:46:32Z We present 60 years of Δ 14 CO 2 measurements from Wellington, New Zealand (41° S, 175° E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest direct atmospheric Δ 14 CO 2 record and records the rise of the 14 C <q>bomb spike</q> and the subsequent decline in Δ 14 CO 2 as bomb 14 C moved throughout the carbon cycle and increasing fossil fuel CO 2 emissions further decreased atmospheric Δ 14 CO 2 . The initially large seasonal cycle in the 1960s reduces in amplitude and eventually reverses in phase, resulting in a small seasonal cycle of about 2 ‰ in the 2000s. The seasonal cycle at Wellington is dominated by the seasonality of cross-tropopause transport and differs slightly from that at Cape Grim, Australia, which is influenced by anthropogenic sources in winter. Δ 14 CO 2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, similar clean-air sites in the Northern Hemisphere show a higher and earlier bomb 14 C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere Δ 14 CO 2 were quite similar, apparently due to the balance of 14 C-free fossil fuel CO 2 emissions in the north and 14 C-depleted ocean upwelling in the south. The Southern Hemisphere sites have shown a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14 C-depleted and carbon-rich deep waters in the Southern Ocean, although an underestimate of fossil fuel CO 2 emissions or changes in biospheric exchange are also possible explanations. This developing Δ 14 CO 2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s and suggests that the upwelling of deep ... Article in Journal/Newspaper Southern Ocean Directory of Open Access Journals: DOAJ Articles Southern Ocean New Zealand Grim ENVELOPE(-64.486,-64.486,-65.379,-65.379) Atmospheric Chemistry and Physics 17 23 14771 14784 |
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Physics QC1-999 Chemistry QD1-999 |
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Physics QC1-999 Chemistry QD1-999 J. C. Turnbull S. E. Mikaloff Fletcher I. Ansell G. W. Brailsford R. C. Moss M. W. Norris K. Steinkamp Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014 |
topic_facet |
Physics QC1-999 Chemistry QD1-999 |
description |
We present 60 years of Δ 14 CO 2 measurements from Wellington, New Zealand (41° S, 175° E). The record has been extended and fully revised. New measurements have been used to evaluate the existing record and to replace original measurements where warranted. This is the earliest direct atmospheric Δ 14 CO 2 record and records the rise of the 14 C <q>bomb spike</q> and the subsequent decline in Δ 14 CO 2 as bomb 14 C moved throughout the carbon cycle and increasing fossil fuel CO 2 emissions further decreased atmospheric Δ 14 CO 2 . The initially large seasonal cycle in the 1960s reduces in amplitude and eventually reverses in phase, resulting in a small seasonal cycle of about 2 ‰ in the 2000s. The seasonal cycle at Wellington is dominated by the seasonality of cross-tropopause transport and differs slightly from that at Cape Grim, Australia, which is influenced by anthropogenic sources in winter. Δ 14 CO 2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, similar clean-air sites in the Northern Hemisphere show a higher and earlier bomb 14 C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere Δ 14 CO 2 were quite similar, apparently due to the balance of 14 C-free fossil fuel CO 2 emissions in the north and 14 C-depleted ocean upwelling in the south. The Southern Hemisphere sites have shown a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14 C-depleted and carbon-rich deep waters in the Southern Ocean, although an underestimate of fossil fuel CO 2 emissions or changes in biospheric exchange are also possible explanations. This developing Δ 14 CO 2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s and suggests that the upwelling of deep ... |
format |
Article in Journal/Newspaper |
author |
J. C. Turnbull S. E. Mikaloff Fletcher I. Ansell G. W. Brailsford R. C. Moss M. W. Norris K. Steinkamp |
author_facet |
J. C. Turnbull S. E. Mikaloff Fletcher I. Ansell G. W. Brailsford R. C. Moss M. W. Norris K. Steinkamp |
author_sort |
J. C. Turnbull |
title |
Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014 |
title_short |
Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014 |
title_full |
Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014 |
title_fullStr |
Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014 |
title_full_unstemmed |
Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014 |
title_sort |
sixty years of radiocarbon dioxide measurements at wellington, new zealand: 1954–2014 |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/acp-17-14771-2017 https://doaj.org/article/744dcbbb084b428c934a184ccedf8785 |
long_lat |
ENVELOPE(-64.486,-64.486,-65.379,-65.379) |
geographic |
Southern Ocean New Zealand Grim |
geographic_facet |
Southern Ocean New Zealand Grim |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Atmospheric Chemistry and Physics, Vol 17, Pp 14771-14784 (2017) |
op_relation |
https://www.atmos-chem-phys.net/17/14771/2017/acp-17-14771-2017.pdf https://doaj.org/toc/1680-7316 https://doaj.org/toc/1680-7324 doi:10.5194/acp-17-14771-2017 1680-7316 1680-7324 https://doaj.org/article/744dcbbb084b428c934a184ccedf8785 |
op_doi |
https://doi.org/10.5194/acp-17-14771-2017 |
container_title |
Atmospheric Chemistry and Physics |
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17 |
container_issue |
23 |
container_start_page |
14771 |
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14784 |
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