Enhanced Southern Ocean CO 2 outgassing as a result of stronger and poleward shifted southern hemispheric westerlies

被引:3
作者
Menviel, Laurie C. [1 ,2 ]
Spence, Paul [2 ,3 ,4 ]
Kiss, Andrew E. [5 ,6 ]
Chamberlain, Matthew A. [3 ,4 ,7 ]
Hayashida, Hakase [3 ,4 ,8 ]
England, Matthew H. [2 ,9 ]
Waugh, Darryn [10 ,11 ]
机构
[1] Univ New South Wales, Climate Change Res Ctr, Sydney, NSW 2052, Australia
[2] Univ New South Wales, Australian Ctr Excellence Antarctic Sci, Sydney, NSW 2052, Australia
[3] Univ Tasmania, Inst Marine & Antarctic Studies, Hobart, Australia
[4] Univ Tasmania, Australian Antarctic Program Partnership, Hobart, Australia
[5] Australian Natl Univ, Res Sch Earth Sci, Canberra, Australia
[6] Australian Res Council, Ctr Excellence Climate Extremes, Canberra, Australia
[7] CSIRO Oceans & Atmosphere, Hobart, Australia
[8] Japan Agcy Marine Earth Sci & Technol, Applicat Lab, Yokohama, Japan
[9] Univ New South Wales, Ctr Marine Sci & Innovat CMSI, Sydney, NSW 2052, Australia
[10] Univ New South Wales, Sch Math & Stat, Sydney, NSW 2052, Australia
[11] Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD USA
基金
澳大利亚研究理事会;
关键词
GLOBAL OCEAN; ATMOSPHERIC CO2; CARBON UPTAKE; ANNULAR MODE; CLIMATE; CIRCULATION; EDDIES; TRENDS; IMPACT; CYCLE;
D O I
10.5194/bg-20-4413-2023
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
While the Southern Ocean (SO) provides the largest oceanic sink of carbon, some observational studies have suggested that the SO total CO2 (tCO(2)) uptake exhibited large (similar to 0.3 GtC yr(-1)) decadal-scale variability over the last 30 years, with a similar SO tCO(2) uptake in 2016 as in the early 1990s. Here, using an eddy-rich ocean, sea-ice, carbon cycle model, with a nominal resolution of 0.1(degrees), we explore the changes in total, natural and anthropogenic SO CO2 fluxes over the period 1980-2021 and the processes leading to the CO2 flux variability. The simulated tCO(2) flux exhibits decadal-scale variability with an amplitude of similar to 0.1 GtC yr(-1) globally in phase with observations. Notably, two stagnations in tCO(2) uptake are simulated: between 1982 and 2000, and between 2003 and 2011, while re-invigorations are simulated between 2000 and 2003, as well as since 2012. This decadal-scale variability is primarily due to changes in natural CO2 (nCO(2)) fluxes south of the polar front associated with variability in the Southern Annular Mode (SAM). Positive phases of the SAM, i.e. stronger and poleward shifted southern hemispheric (SH) westerlies, lead to enhanced SO nCO(2) outgassing due to higher surface natural dissolved inorganic carbon (DIC) brought about by a combination of Ekman-driven vertical advection and DIC diffusion at the base of the mixed layer. The pattern of the CO2 flux anomalies indicate a dominant control of the interaction between the mean flow south of the polar front and the main topographic features. While positive phases of the SAM also lead to enhanced anthropogenic CO2 (aCO(2)) uptake south of the polar front, the amplitude of the changes in aCO(2) fluxes is only 25 % of the changes in nCO(2) fluxes. Due to the larger nCO(2) outgassing compared to aCO(2) uptake as the SH westerlies strengthen and shift poleward, the SO tCO(2) uptake capability thus reduced since 1980 in response to the shift towards positive phases of the SAM. Our results indicate that, even in an eddy-rich ocean model, a strengthening and/or poleward shift of the SH westerlies enhance CO2 outgassing. The projected poleward strengthening of the SH westerlies over the coming century will, thus, reduce the capability of the SO to mitigate the increase in atmospheric CO2.
引用
收藏
页码:4413 / 4431
页数:19
相关论文
共 50 条
  • [41] Importance of water mass formation regions for the air-sea CO2 flux estimate in the Southern Ocean
    Barbero, Leticia
    Boutin, Jacqueline
    Merlivat, Liliane
    Martin, Nicolas
    Takahashi, Taro
    Sutherland, Stewart C.
    Wanninkhof, Rik
    GLOBAL BIOGEOCHEMICAL CYCLES, 2011, 25
  • [42] Reassessing Southern Ocean Air-Sea CO2 Flux Estimates With the Addition of Biogeochemical Float Observations
    Bushinsky, Seth M.
    Landschuetzer, Peter
    Roedenbeck, Christian
    Gray, Alison R.
    Baker, David
    Mazloff, Matthew R.
    Resplandy, Laure
    Johnson, Kenneth S.
    Sarmiento, Jorge L.
    GLOBAL BIOGEOCHEMICAL CYCLES, 2019, 33 (11) : 1370 - 1388
  • [43] Southern Ocean control on atmospheric CO2 changes across late Pliocene Marine Isotope Stage M2
    Hou, Suning
    Toebrock, Leonie
    van der Linden, Mart
    Rothstegge, Fleur
    Ziegler, Martin
    Lourens, Lucas J.
    Bijl, Peter K.
    CLIMATE OF THE PAST, 2025, 21 (01) : 79 - 93
  • [44] Southern Ocean wind response to North Atlantic cooling and the rise in atmospheric CO2: Modeling perspective and paleoceanographic implications
    Lee, Shih-Yu
    Chiang, John C. H.
    Matsumoto, Katsumi
    Tokos, Kathy S.
    PALEOCEANOGRAPHY, 2011, 26
  • [45] Variability and stability of anthropogenic CO2 in Antarctic Bottom Water observed in the Indian sector of the Southern Ocean, 1978-2018
    Mahieu, Leo
    Lo Monaco, Claire
    Metzl, Nicolas
    Fin, Jonathan
    Mignon, Claude
    OCEAN SCIENCE, 2020, 16 (06) : 1559 - 1576
  • [46] Recent evidence for a strengthening CO2 sink in the Southern Ocean from carbonate system measurements in the Drake Passage (2002-2015)
    Munro, David R.
    Lovenduski, Nicole S.
    Takahashi, Taro
    Stephens, Britton B.
    Newberger, Timothy
    Sweeney, Colm
    GEOPHYSICAL RESEARCH LETTERS, 2015, 42 (18) : 7623 - 7630
  • [47] Spatial and temporal variability of the physical, carbonate and CO2 properties in the Southern Ocean surface waters during austral summer (2005-2019)
    Brandon, Margaux
    Goyet, Catherine
    Touratier, Franck
    Lefevre, Nathalie
    Kestenare, Elodie
    Morrow, Rosemary
    DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS, 2022, 187
  • [48] Variations of oceanic pCO2 and air-sea CO2 flux in the eastern Indian sector of the Southern Ocean for the austral summer of 2001-2002
    Nakaoka, Shin-ichiro
    Nakazawa, Takakiyo
    Yoshikawa-Inoue, Hisayuki
    Aoki, Shuji
    Hashida, Gen
    Ishii, Masao
    Yamanouchi, Takashi
    Odate, Tsuneo
    Fukuchi, Mitsuo
    GEOPHYSICAL RESEARCH LETTERS, 2009, 36
  • [49] Interannual variability of net community production and air-sea CO2 flux in a naturally iron fertilized region of the Southern Ocean (Kerguelen Plateau)
    Jouandet, Marie Paule
    Blain, Stephane
    Metzl, Nicolas
    Mongin, Mathieu
    ANTARCTIC SCIENCE, 2011, 23 (06) : 589 - 596
  • [50] Roles of Surface Forcing in the Southern Ocean Temperature and Salinity Changes under Increasing CO2: Perspectives from Model Perturbation Experiments and a Theoretical Framework
    Lyu, Kewei
    Zhang, Xuebin
    Church, John A.
    Wu, Quran
    Fiedler, Russell
    Dias, Fabio Boeira
    JOURNAL OF PHYSICAL OCEANOGRAPHY, 2023, 53 (01) : 19 - 36