Improved atmospheric constraints on Southern Ocean CO2 exchange
We present improved estimates of air-sea CO2 exchange over three latitude bands of the Southern Ocean using atmospheric CO2 measurements from global airborne campaigns and an atmospheric 4 - box inverse model based on a mass- indexed isentropic coordinate (M theta e). These flux estimates show two f...
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Online Access: | https://doi.org/10.1073/pnas.2309333121 |
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ftncar:oai:drupal-site.org:articles_27018 2024-04-21T08:12:11+00:00 Improved atmospheric constraints on Southern Ocean CO2 exchange Jin, Yuming (author) Keeling, Ralph F. (author) Stephens, Britton B. (author) Long, Matthew C. (author) Patra, Prabir K. (author) Rödenbeck, Christian (author) Morgan, Eric J. (author) Kort, Eric A. (author) Sweeney, Colm (author) 2024-01-30 https://doi.org/10.1073/pnas.2309333121 en eng Proceedings of the National Academy of Sciences--Proc. Natl. Acad. Sci. U.S.A.--0027-8424--1091-6490 The ocean carbon sink estimate in the Global Carbon Budget 2019--10.1594/PANGAEA.920753 CarbonTracker CT2019B--10.25925/20201008 HIPPO Merged 10-Second Meteorology, Atmospheric Chemistry, and Aerosol Data. Version 1.0--10.3334/CDIAC/HIPPO_010 ATom: Merged Atmospheric Chemistry, Trace Gases, and Aerosols, Version 2--10.3334/ORNLDAAC/1925 ORCAS Merge Products. Version 1.0--10.5065/D6SB445X Atmospheric Flask CO2 and Isotopic Data - Multiple Sampling Stations. In Scripps CO2 Program Data--10.6075/J0HQ3X30 articles:27018 doi:10.1073/pnas.2309333121 ark:/85065/d7348qjb Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. article Text 2024 ftncar https://doi.org/10.1073/pnas.2309333121 2024-04-11T00:19:42Z We present improved estimates of air-sea CO2 exchange over three latitude bands of the Southern Ocean using atmospheric CO2 measurements from global airborne campaigns and an atmospheric 4 - box inverse model based on a mass- indexed isentropic coordinate (M theta e). These flux estimates show two features not clearly resolved in previous estimates based on inverting surface CO2 measurements: a weak winter - time outgassing in the polar region and a sharp phase transition of the seasonal flux cycles between polar/subpolar and subtropical regions. The estimates suggest much stronger summer - time uptake in the polar/subpolar regions than estimates derived through neural- network interpolation of pCO2 data obtained with profiling floats but somewhat weaker uptake than a recent study by Long et al. [Science 374, 1275-1280 (2021)], who used the same airborne data and multiple atmospheric transport models (ATMs) to constrain surface fluxes. Our study also uses moist static energy (MSE) budgets from reanalyses to show that most ATMs tend to have excessive diabatic mixing (transport across moist isentrope, 0e, or M theta e surfaces) at high southern latitudes in the austral summer, which leads to biases in estimates of air-sea CO2 exchange. Furthermore, we show that the MSE-based constraint is consistent with an independent constraint on atmospheric mixing based on combining airborne and surface CO2 observations. 1547626 1623745 1501993 Article in Journal/Newspaper Southern Ocean OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Proceedings of the National Academy of Sciences 121 6 |
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 improved estimates of air-sea CO2 exchange over three latitude bands of the Southern Ocean using atmospheric CO2 measurements from global airborne campaigns and an atmospheric 4 - box inverse model based on a mass- indexed isentropic coordinate (M theta e). These flux estimates show two features not clearly resolved in previous estimates based on inverting surface CO2 measurements: a weak winter - time outgassing in the polar region and a sharp phase transition of the seasonal flux cycles between polar/subpolar and subtropical regions. The estimates suggest much stronger summer - time uptake in the polar/subpolar regions than estimates derived through neural- network interpolation of pCO2 data obtained with profiling floats but somewhat weaker uptake than a recent study by Long et al. [Science 374, 1275-1280 (2021)], who used the same airborne data and multiple atmospheric transport models (ATMs) to constrain surface fluxes. Our study also uses moist static energy (MSE) budgets from reanalyses to show that most ATMs tend to have excessive diabatic mixing (transport across moist isentrope, 0e, or M theta e surfaces) at high southern latitudes in the austral summer, which leads to biases in estimates of air-sea CO2 exchange. Furthermore, we show that the MSE-based constraint is consistent with an independent constraint on atmospheric mixing based on combining airborne and surface CO2 observations. 1547626 1623745 1501993 |
author2 |
Jin, Yuming (author) Keeling, Ralph F. (author) Stephens, Britton B. (author) Long, Matthew C. (author) Patra, Prabir K. (author) Rödenbeck, Christian (author) Morgan, Eric J. (author) Kort, Eric A. (author) Sweeney, Colm (author) |
format |
Article in Journal/Newspaper |
title |
Improved atmospheric constraints on Southern Ocean CO2 exchange |
spellingShingle |
Improved atmospheric constraints on Southern Ocean CO2 exchange |
title_short |
Improved atmospheric constraints on Southern Ocean CO2 exchange |
title_full |
Improved atmospheric constraints on Southern Ocean CO2 exchange |
title_fullStr |
Improved atmospheric constraints on Southern Ocean CO2 exchange |
title_full_unstemmed |
Improved atmospheric constraints on Southern Ocean CO2 exchange |
title_sort |
improved atmospheric constraints on southern ocean co2 exchange |
publishDate |
2024 |
url |
https://doi.org/10.1073/pnas.2309333121 |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Proceedings of the National Academy of Sciences--Proc. Natl. Acad. Sci. U.S.A.--0027-8424--1091-6490 The ocean carbon sink estimate in the Global Carbon Budget 2019--10.1594/PANGAEA.920753 CarbonTracker CT2019B--10.25925/20201008 HIPPO Merged 10-Second Meteorology, Atmospheric Chemistry, and Aerosol Data. Version 1.0--10.3334/CDIAC/HIPPO_010 ATom: Merged Atmospheric Chemistry, Trace Gases, and Aerosols, Version 2--10.3334/ORNLDAAC/1925 ORCAS Merge Products. Version 1.0--10.5065/D6SB445X Atmospheric Flask CO2 and Isotopic Data - Multiple Sampling Stations. In Scripps CO2 Program Data--10.6075/J0HQ3X30 articles:27018 doi:10.1073/pnas.2309333121 ark:/85065/d7348qjb |
op_rights |
Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
op_doi |
https://doi.org/10.1073/pnas.2309333121 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
121 |
container_issue |
6 |
_version_ |
1796932166697877504 |