Wellington atmospheric 14CO2

We present 60 years of Δ14CO2 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 atmospheric Δ14CO2 record and records the rise of the 14C “bomb spike”, the subsequent decline in Δ14CO2 as bomb 14C moved throughout the carbon cycle and increasing fossil fuel CO2 emissions further decreased atmospheric Δ14CO2. 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. Δ14CO2 at Cape Grim and Wellington show very similar trends, with significant differences only during periods of known measurement uncertainty. In contrast, Northern Hemisphere clean air sites show a higher and earlier bomb 14C peak, consistent with a 1.4-year interhemispheric exchange time. From the 1970s until the early 2000s, the Northern and Southern Hemisphere Δ14CO2 were quite similar, apparently due to the balance of 14C-free fossil fuel CO2 emissions in the north and 14C-depleted ocean upwelling in the south. The Southern Hemisphere sites show a consistent and marked elevation above the Northern Hemisphere sites since the early 2000s, which is most likely due to reduced upwelling of 14C-depleted and carbon-rich deep waters in the Southern Ocean. This developing Δ14CO2 interhemispheric gradient is consistent with recent studies that indicate a reinvigorated Southern Ocean carbon sink since the mid-2000s, and suggests that upwelling of deep waters plays an important role in this change.


DOI:

https://doi.org/10.5194/acp-17-14771-2017


Cite as:

Turnbull, J. C., Mikaloff Fletcher, S. E., Ansell, I., Brailsford, G. W., Moss, R. C., Norris, M. W., and Steinkamp, K.: Sixty years of radiocarbon dioxide measurements at Wellington, New Zealand: 1954–2014, Atmos. Chem. Phys., 17, 14771–14784, https://doi.org/10.5194/acp-17-14771-2017, 2017 .

Simple

Date (Revision)
2017-02-10
Status
On going
Point of contact
Organisation name Individual name Electronic mail address Role

GNS Science

radiocarbon@gns.cri.nz

Point of contact
Maintenance and update frequency
As needed
Keywords

  • carbon cycle

  • greenhouse gases

  • atmospheric trace gas observations
Classification
Unclassified
Use constraints
Other restrictions
Other constraints

Fair use policy. Users are strongly encouraged to contact us prior to use of this data, and must ensure that this work is acknowledged appropriately.


Every care has been taken to ensure the accuracy of information. However, GNS Science accepts no responsibility for any errors, omissions, or inaccuracies in the information. Nor will GNS Science be liable for any loss or damage suffered as a result of reliance on this information, or through directly or indirectly applying it.
Language
English
Topic category
  • Climatology, meteorology, atmosphere
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Begin date
1954-12-01
End date
2014-12-31
Distribution format
Name Version

text
OnLine resource
Protocol Linkage Name

WWW:LINK-1.0-http--link

 		https://gaw.kishou.go.jp/#:~:text=The%20World%20Data%20Centre%20for,World%20Meteorological%20Organization%20(WMO).&text=This%20website%20is%20operated%20by%20the%20JMA%20in%20collaboration%20with%20WMO.

World Data Centre for Greenhouse Gases

WWW:LINK-1.0-http--link

 		https://acp.copernicus.org/articles/17/14771/2017/

Journal paper

WWW:DOWNLOAD-1.0-http--download

 		https://huta22.gns.cri.nz/metadata/srv/api/records/adeece18-5fe0-4be0-9e60-eb2ace99ec04/attachments/BHD_14CO2_datasets_20211013.xlsx
OnLine resource
Protocol Linkage Name
ftp://ftp.niwa.co.nz/tropac/co2/14co2/

NIWA ftp server

Metadata

File identifier
adeece18-5fe0-4be0-9e60-eb2ace99ec04 XML
Metadata language
English
Character set
UTF8
Hierarchy level
Dataset
Hierarchy level name

Dataset
Date stamp
2022-03-04T12:10:25
Metadata standard name

ISO 19115:2003/19139
Metadata standard version

1.0
Metadata author
Organisation name Individual name Electronic mail address Role

GNS Science

j.turnbull@gns.cri.nz

Point of contact
 
 

Overviews

overview
Wellington D14CO2 Record 1954-present

Spatial extent

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Keywords


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