Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand
We present an analysis of a 39-year record of continuous atmospheric CO₂ observations made at Baring Head, New Zealand, filtered for steady background CO₂ mole fractions during southerly wind conditions. We discuss relationships between variability in the filtered CO₂ time series and regional to glo...
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Language: | English |
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Copernicus Publications
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ftncar:oai:drupal-site.org:articles_12653 2023-09-05T13:23:14+02:00 Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand Stephens, Britton (author) Brailsford, G. (author) Gomez, A. (author) Riedel, K. (author) Mikaloff Fletcher, S. (author) Nichol, S. (author) Manning, M. (author) 2013-04-23 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-902 https://doi.org/10.5194/bg-10-2683-2013 en eng Copernicus Publications Biogeosciences http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-902 doi:10.5194/bg-10-2683-2013 ark:/85065/d7k938db Copyright 2013 Authors. Text article 2013 ftncar https://doi.org/10.5194/bg-10-2683-2013 2023-08-14T18:40:46Z We present an analysis of a 39-year record of continuous atmospheric CO₂ observations made at Baring Head, New Zealand, filtered for steady background CO₂ mole fractions during southerly wind conditions. We discuss relationships between variability in the filtered CO₂ time series and regional to global carbon cycling. Baring Head is well situated to sample air that has been isolated from terrestrial influences over the Southern Ocean, and experiences extended episodes of strong southerly winds with low CO₂ variability. The filtered Baring Head CO₂ record reveals an average seasonal cycle with amplitude of 0.95 ppm that is 13% smaller and 3 weeks earlier in phase than that at the South Pole. Seasonal variations in a given year are sensitive to the timing and magnitude of the combined influences of Southern Ocean CO₂ fluxes and terrestrial fluxes from both hemispheres. The amplitude of the seasonal cycle varies throughout the record, but we find no significant long-term seasonal changes with respect to the South Pole. Interannual variations in CO₂ growth rate in the Baring Head record closely match the El Niño-Southern Oscillation, reflecting the global reach of CO₂ mole fraction anomalies associated with this cycle. We use atmospheric transport model results to investigate contributions to seasonal and annual-mean components of the observed CO₂ record. Long-term trends in mean gradients between Baring Head and other stations are predominately due to increases in Northern Hemisphere fossil-fuel burning and Southern Ocean CO₂ uptake, for which there remains a wide range of future estimates. We find that the postulated recent reduction in the efficiency of Southern Ocean anthropogenic CO₂ uptake, as a result of increased zonal winds, is too small to be detectable as significant differences in atmospheric CO₂ between mid to high latitude Southern Hemisphere observing stations. Article in Journal/Newspaper South pole Southern Ocean OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) New Zealand South Pole Southern Ocean Biogeosciences 10 4 2683 2697 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
We present an analysis of a 39-year record of continuous atmospheric CO₂ observations made at Baring Head, New Zealand, filtered for steady background CO₂ mole fractions during southerly wind conditions. We discuss relationships between variability in the filtered CO₂ time series and regional to global carbon cycling. Baring Head is well situated to sample air that has been isolated from terrestrial influences over the Southern Ocean, and experiences extended episodes of strong southerly winds with low CO₂ variability. The filtered Baring Head CO₂ record reveals an average seasonal cycle with amplitude of 0.95 ppm that is 13% smaller and 3 weeks earlier in phase than that at the South Pole. Seasonal variations in a given year are sensitive to the timing and magnitude of the combined influences of Southern Ocean CO₂ fluxes and terrestrial fluxes from both hemispheres. The amplitude of the seasonal cycle varies throughout the record, but we find no significant long-term seasonal changes with respect to the South Pole. Interannual variations in CO₂ growth rate in the Baring Head record closely match the El Niño-Southern Oscillation, reflecting the global reach of CO₂ mole fraction anomalies associated with this cycle. We use atmospheric transport model results to investigate contributions to seasonal and annual-mean components of the observed CO₂ record. Long-term trends in mean gradients between Baring Head and other stations are predominately due to increases in Northern Hemisphere fossil-fuel burning and Southern Ocean CO₂ uptake, for which there remains a wide range of future estimates. We find that the postulated recent reduction in the efficiency of Southern Ocean anthropogenic CO₂ uptake, as a result of increased zonal winds, is too small to be detectable as significant differences in atmospheric CO₂ between mid to high latitude Southern Hemisphere observing stations. |
author2 |
Stephens, Britton (author) Brailsford, G. (author) Gomez, A. (author) Riedel, K. (author) Mikaloff Fletcher, S. (author) Nichol, S. (author) Manning, M. (author) |
format |
Article in Journal/Newspaper |
title |
Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand |
spellingShingle |
Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand |
title_short |
Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand |
title_full |
Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand |
title_fullStr |
Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand |
title_full_unstemmed |
Analysis of a 39-year continuous atmospheric CO₂ record from Baring Head, New Zealand |
title_sort |
analysis of a 39-year continuous atmospheric co₂ record from baring head, new zealand |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-902 https://doi.org/10.5194/bg-10-2683-2013 |
geographic |
New Zealand South Pole Southern Ocean |
geographic_facet |
New Zealand South Pole Southern Ocean |
genre |
South pole Southern Ocean |
genre_facet |
South pole Southern Ocean |
op_relation |
Biogeosciences http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-018-902 doi:10.5194/bg-10-2683-2013 ark:/85065/d7k938db |
op_rights |
Copyright 2013 Authors. |
op_doi |
https://doi.org/10.5194/bg-10-2683-2013 |
container_title |
Biogeosciences |
container_volume |
10 |
container_issue |
4 |
container_start_page |
2683 |
op_container_end_page |
2697 |
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1776203794003001344 |