Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport
We use an inverse method to estimate the global-scale pattern of the air-sea flux of natural CO2, i.e., the component of the CO2 flux due to the natural carbon cycle that already existed in preindustrial times, on the basis of ocean interior observations of dissolved inorganic carbon (DIC) and other...
Published in: | Global Biogeochemical Cycles |
---|---|
Main Authors: | , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union
2007
|
Subjects: | |
Online Access: | https://boris.unibe.ch/25258/1/2006GB002751.pdf https://boris.unibe.ch/25258/ |
id |
ftunivbern:oai:boris.unibe.ch:25258 |
---|---|
record_format |
openpolar |
spelling |
ftunivbern:oai:boris.unibe.ch:25258 2023-08-20T04:09:59+02:00 Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport Mikaloff Fletcher, S. E. Gruber, N. Jacobson, A. R. Gloor, M. Doney, S. C. Dutkiewicz, S. Gerber, M. Follows, M. Joos, F. Lindsay, K. Menemenlis, D. Mouchet, A. Müller, S. A. Sarmiento, J. L. 2007 application/pdf https://boris.unibe.ch/25258/1/2006GB002751.pdf https://boris.unibe.ch/25258/ eng eng American Geophysical Union https://boris.unibe.ch/25258/ info:eu-repo/semantics/openAccess Mikaloff Fletcher, S. E.; Gruber, N.; Jacobson, A. R.; Gloor, M.; Doney, S. C.; Dutkiewicz, S.; Gerber, M.; Follows, M.; Joos, F.; Lindsay, K.; Menemenlis, D.; Mouchet, A.; Müller, S. A.; Sarmiento, J. L. (2007). Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport. Global biogeochemical cycles, 21(1) Washington, D.C.: American Geophysical Union 10.1029/2006GB002751 <http://dx.doi.org/10.1029/2006GB002751> 530 Physics info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion PeerReviewed 2007 ftunivbern https://doi.org/10.1029/2006GB002751 2023-07-31T20:48:45Z We use an inverse method to estimate the global-scale pattern of the air-sea flux of natural CO2, i.e., the component of the CO2 flux due to the natural carbon cycle that already existed in preindustrial times, on the basis of ocean interior observations of dissolved inorganic carbon (DIC) and other tracers, from which we estimate ΔCgasex, i.e., the component of the observed DIC that is due to the gas exchange of natural CO2. We employ a suite of 10 different Ocean General Circulation Models (OGCMs) to quantify the error arising from uncertainties in the modeled transport required to link the interior ocean observations to the surface fluxes. The results from the contributing OGCMs are weighted using a model skill score based on a comparison of each model's simulated natural radiocarbon with observations. We find a pattern of air-sea flux of natural CO2 characterized by outgassing in the Southern Ocean between 44°S and 59°S, vigorous uptake at midlatitudes of both hemispheres, and strong outgassing in the tropics. In the Northern Hemisphere and the tropics, the inverse estimates generally agree closely with the natural CO2 flux results from forward simulations of coupled OGCM-biogeochemistry models undertaken as part of the second phase of the Ocean Carbon Model Intercomparison Project (OCMIP-2). The OCMIP-2 simulations find far less air-sea exchange than the inversion south of 20°S, but more recent forward OGCM studies are in better agreement with the inverse estimates in the Southern Hemisphere. The strong source and sink pattern south of 20°S was not apparent in an earlier inversion study, because the choice of region boundaries led to a partial cancellation of the sources and sinks. We show that the inversely estimated flux pattern is clearly traceable to gradients in the observed ΔCgasex, and that it is relatively insensitive to the choice of OGCM or potential biases in ΔCgasex. Our inverse estimates imply a southward interhemispheric transport of 0.31 ± 0.02 Pg C yr−1, most of which occurs in the Atlantic. ... Article in Journal/Newspaper Southern Ocean BORIS (Bern Open Repository and Information System, University of Bern) Southern Ocean Global Biogeochemical Cycles 21 1 |
institution |
Open Polar |
collection |
BORIS (Bern Open Repository and Information System, University of Bern) |
op_collection_id |
ftunivbern |
language |
English |
topic |
530 Physics |
spellingShingle |
530 Physics Mikaloff Fletcher, S. E. Gruber, N. Jacobson, A. R. Gloor, M. Doney, S. C. Dutkiewicz, S. Gerber, M. Follows, M. Joos, F. Lindsay, K. Menemenlis, D. Mouchet, A. Müller, S. A. Sarmiento, J. L. Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport |
topic_facet |
530 Physics |
description |
We use an inverse method to estimate the global-scale pattern of the air-sea flux of natural CO2, i.e., the component of the CO2 flux due to the natural carbon cycle that already existed in preindustrial times, on the basis of ocean interior observations of dissolved inorganic carbon (DIC) and other tracers, from which we estimate ΔCgasex, i.e., the component of the observed DIC that is due to the gas exchange of natural CO2. We employ a suite of 10 different Ocean General Circulation Models (OGCMs) to quantify the error arising from uncertainties in the modeled transport required to link the interior ocean observations to the surface fluxes. The results from the contributing OGCMs are weighted using a model skill score based on a comparison of each model's simulated natural radiocarbon with observations. We find a pattern of air-sea flux of natural CO2 characterized by outgassing in the Southern Ocean between 44°S and 59°S, vigorous uptake at midlatitudes of both hemispheres, and strong outgassing in the tropics. In the Northern Hemisphere and the tropics, the inverse estimates generally agree closely with the natural CO2 flux results from forward simulations of coupled OGCM-biogeochemistry models undertaken as part of the second phase of the Ocean Carbon Model Intercomparison Project (OCMIP-2). The OCMIP-2 simulations find far less air-sea exchange than the inversion south of 20°S, but more recent forward OGCM studies are in better agreement with the inverse estimates in the Southern Hemisphere. The strong source and sink pattern south of 20°S was not apparent in an earlier inversion study, because the choice of region boundaries led to a partial cancellation of the sources and sinks. We show that the inversely estimated flux pattern is clearly traceable to gradients in the observed ΔCgasex, and that it is relatively insensitive to the choice of OGCM or potential biases in ΔCgasex. Our inverse estimates imply a southward interhemispheric transport of 0.31 ± 0.02 Pg C yr−1, most of which occurs in the Atlantic. ... |
format |
Article in Journal/Newspaper |
author |
Mikaloff Fletcher, S. E. Gruber, N. Jacobson, A. R. Gloor, M. Doney, S. C. Dutkiewicz, S. Gerber, M. Follows, M. Joos, F. Lindsay, K. Menemenlis, D. Mouchet, A. Müller, S. A. Sarmiento, J. L. |
author_facet |
Mikaloff Fletcher, S. E. Gruber, N. Jacobson, A. R. Gloor, M. Doney, S. C. Dutkiewicz, S. Gerber, M. Follows, M. Joos, F. Lindsay, K. Menemenlis, D. Mouchet, A. Müller, S. A. Sarmiento, J. L. |
author_sort |
Mikaloff Fletcher, S. E. |
title |
Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport |
title_short |
Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport |
title_full |
Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport |
title_fullStr |
Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport |
title_full_unstemmed |
Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport |
title_sort |
inverse estimates of the oceanic sources and sinks of natural co2 and the implied oceanic carbon transport |
publisher |
American Geophysical Union |
publishDate |
2007 |
url |
https://boris.unibe.ch/25258/1/2006GB002751.pdf https://boris.unibe.ch/25258/ |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Mikaloff Fletcher, S. E.; Gruber, N.; Jacobson, A. R.; Gloor, M.; Doney, S. C.; Dutkiewicz, S.; Gerber, M.; Follows, M.; Joos, F.; Lindsay, K.; Menemenlis, D.; Mouchet, A.; Müller, S. A.; Sarmiento, J. L. (2007). Inverse estimates of the oceanic sources and sinks of natural CO2 and the implied oceanic carbon transport. Global biogeochemical cycles, 21(1) Washington, D.C.: American Geophysical Union 10.1029/2006GB002751 <http://dx.doi.org/10.1029/2006GB002751> |
op_relation |
https://boris.unibe.ch/25258/ |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2006GB002751 |
container_title |
Global Biogeochemical Cycles |
container_volume |
21 |
container_issue |
1 |
_version_ |
1774723804851863552 |