On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems
The air-sea CO 2 fluxes in eastern boundary upwelling systems (EBUSs)vary strongly in time and space, with some of the highest flux densities globally. The processes controlling this variability have not yet been investigated consistently across all four major EBUSs, i.e., the California (CalCS), Hu...
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ftosti:oai:osti.gov:1610355 2023-07-30T04:05:37+02:00 On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems Brady, Riley X. Lovenduski, Nicole S. Alexander, Michael A. Jacox, Michael Gruber, Nicolas 2022-05-30 application/pdf http://www.osti.gov/servlets/purl/1610355 https://www.osti.gov/biblio/1610355 https://doi.org/10.5194/bg-16-329-2019 unknown http://www.osti.gov/servlets/purl/1610355 https://www.osti.gov/biblio/1610355 https://doi.org/10.5194/bg-16-329-2019 doi:10.5194/bg-16-329-2019 54 ENVIRONMENTAL SCIENCES 2022 ftosti https://doi.org/10.5194/bg-16-329-2019 2023-07-11T09:41:10Z The air-sea CO 2 fluxes in eastern boundary upwelling systems (EBUSs)vary strongly in time and space, with some of the highest flux densities globally. The processes controlling this variability have not yet been investigated consistently across all four major EBUSs, i.e., the California (CalCS), Humboldt (HumCS), Canary (CanCS), and Benguela (BenCS) Current systems. In this study, we diagnose the climatic modes of the air–sea CO 2 flux variability in these regions between 1920 and 2015, using simulation results from the Community Earth System Model Large Ensemble(CESM-LENS), a global coupled climate model ensemble that is forced by historical and RCP8.5 radiative forcing. Differences between simulations canbe attributed entirely to internal (unforced) climate variability, whose contribution can be diagnosed by subtracting the ensemble mean from each simulation. We find that in the CalCS and CanCS, the resulting anomalous CO 2 fluxes are strongly affected by large-scale extratropical modesof variability, i.e., the North Pacific Gyre Oscillation (NPGO) and the North Atlantic Oscillation (NAO), respectively. The CalCS has anomalous uptake of CO 2 during the positive phase of the NPGO, while the CanCS has anomalous outgassing of CO 2 during the positive phase of the NAO. In contrast, the HumCS is mainly affected by El Niño–Southern Oscillation(ENSO), with anomalous uptake of CO 2 during an El Niño event.Variations in dissolved inorganic carbon (DIC) and sea surface temperature(SST) are the major contributors to these anomalous CO 2 fluxes and are generally driven by changes to large-scale gyre circulation, upwelling,the mixed layer depth, and biological processes. A better understanding of the sensitivity of EBUS CO 2 fluxes to modes of climate variability is key in improving our ability to predict the future evolution of the atmospheric CO 2 source and sink characteristics of the four EBUSs. Other/Unknown Material North Atlantic North Atlantic oscillation SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Pacific Biogeosciences 16 2 329 346 |
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Open Polar |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
54 ENVIRONMENTAL SCIENCES |
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54 ENVIRONMENTAL SCIENCES Brady, Riley X. Lovenduski, Nicole S. Alexander, Michael A. Jacox, Michael Gruber, Nicolas On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems |
topic_facet |
54 ENVIRONMENTAL SCIENCES |
description |
The air-sea CO 2 fluxes in eastern boundary upwelling systems (EBUSs)vary strongly in time and space, with some of the highest flux densities globally. The processes controlling this variability have not yet been investigated consistently across all four major EBUSs, i.e., the California (CalCS), Humboldt (HumCS), Canary (CanCS), and Benguela (BenCS) Current systems. In this study, we diagnose the climatic modes of the air–sea CO 2 flux variability in these regions between 1920 and 2015, using simulation results from the Community Earth System Model Large Ensemble(CESM-LENS), a global coupled climate model ensemble that is forced by historical and RCP8.5 radiative forcing. Differences between simulations canbe attributed entirely to internal (unforced) climate variability, whose contribution can be diagnosed by subtracting the ensemble mean from each simulation. We find that in the CalCS and CanCS, the resulting anomalous CO 2 fluxes are strongly affected by large-scale extratropical modesof variability, i.e., the North Pacific Gyre Oscillation (NPGO) and the North Atlantic Oscillation (NAO), respectively. The CalCS has anomalous uptake of CO 2 during the positive phase of the NPGO, while the CanCS has anomalous outgassing of CO 2 during the positive phase of the NAO. In contrast, the HumCS is mainly affected by El Niño–Southern Oscillation(ENSO), with anomalous uptake of CO 2 during an El Niño event.Variations in dissolved inorganic carbon (DIC) and sea surface temperature(SST) are the major contributors to these anomalous CO 2 fluxes and are generally driven by changes to large-scale gyre circulation, upwelling,the mixed layer depth, and biological processes. A better understanding of the sensitivity of EBUS CO 2 fluxes to modes of climate variability is key in improving our ability to predict the future evolution of the atmospheric CO 2 source and sink characteristics of the four EBUSs. |
author |
Brady, Riley X. Lovenduski, Nicole S. Alexander, Michael A. Jacox, Michael Gruber, Nicolas |
author_facet |
Brady, Riley X. Lovenduski, Nicole S. Alexander, Michael A. Jacox, Michael Gruber, Nicolas |
author_sort |
Brady, Riley X. |
title |
On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems |
title_short |
On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems |
title_full |
On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems |
title_fullStr |
On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems |
title_full_unstemmed |
On the role of climate modes in modulating the air–sea CO 2 fluxes in eastern boundary upwelling systems |
title_sort |
on the role of climate modes in modulating the air–sea co 2 fluxes in eastern boundary upwelling systems |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1610355 https://www.osti.gov/biblio/1610355 https://doi.org/10.5194/bg-16-329-2019 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
http://www.osti.gov/servlets/purl/1610355 https://www.osti.gov/biblio/1610355 https://doi.org/10.5194/bg-16-329-2019 doi:10.5194/bg-16-329-2019 |
op_doi |
https://doi.org/10.5194/bg-16-329-2019 |
container_title |
Biogeosciences |
container_volume |
16 |
container_issue |
2 |
container_start_page |
329 |
op_container_end_page |
346 |
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1772817647753232384 |