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SCIENCE CHINA Earth Sciences, Volume 61 , Issue 6 : 804-822(2018) https://doi.org/10.1007/s11430-017-9173-y

Simulated effects of interactions between ocean acidification, marine organism calcification, and organic carbon export on ocean carbon and oxygen cycles

More info
  • ReceivedMar 30, 2017
  • AcceptedJan 30, 2018
  • PublishedMar 20, 2018

Abstract


Funded by

the National Natural Science Foundation of China(Grant,Nos.,41675063,41422503,&,41276073)

the National Key Basic Research Program of China(Grant,No.,2015CB953601)

and the Fundamental Research Funds for the Central Universities.


Acknowledgment

This study was supported by the National Natural Science Foundation of China (Grant Nos. 41675063, 41422503 & 41276073), the National Key Basic Research Program of China (Grant No. 2015CB953601), and the Fundamental Research Funds for the Central Universities.


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  • Figure 1

    Model-simulated (a) latitude-depth distribution of sea surface ΩC at year 1800, and (b) time-depth distribution of the change (relative to 1800) of ΩC (ΔΩC) in simulation CAL. Refer to Table 1 for detailed configurations of different model versions. These figures were generated using software UV-CDAT (http://uvcdat.llnl.gov/).

  • Figure 2

    Prescribed atmospheric CO2 emission scenario used to drive the model. From year 1800 to 2100, CO2 emissions follow the historical data and IPCC SRES A2 CO2 emission pathway. After year 2100, we assume a linear decline of CO2 emission that reaches zero at year 2319 with a cumulative CO2 emission of 5000 Pg C after year 2000.

  • Figure 3

    Model-simulated seawater-air CO2 flux compared with observational-based estimates for the reference year 2000. Results shown are the maps of seawater-air CO2 flux for (a) observational estimates (Takahashi et al., 2009), and simulations of (b) REF and (c) BAL2. Zonal mean seawater-air CO2 flux is also shown (d). Figure (a)–(c) were generated using software UV-CDAT (http://uvcdat.llnl.gov/).

  • Figure 4

    Model-simulated global mean vertical profiles of ((a), (c), (e)) dissolved inorganic carbon (DIC) and ((b), (d), (f)) alkalinity (ALK) (1990–1999 average) compared with observational estimates of GLODAP data (gray shaded areas denote estimated uncertainties (Key et al., 2004). Results shown are for ((a), (b)) the global ocean, ((c), (d)) the Arc-Atlantic Ocean, and ((e), (f)) the Pacific-Indian Ocean. Model-simulated results are shown for the four simulations corresponding to the four parameterizations provided in Table 1.

  • Figure 5

    Model-simulated time series of (a) atmospheric CO2 concentration, (b) global mean surface air temperature (SAT), (c) global mean sea surface pH, (d) global mean sea surface alkalinity concentration, (e) global mean sea surface [CO32], (f) global mean sea surface ΩC; model-simulated time series of the change (relative to year 1800) in mean [O2] at ocean depths of (g) ~180–300 m and (h) ~1100–3200 m. Refer to Table 1 for detailed configurations of different model versions.

  • Figure 6

    Model-simulated (a) time series of cumulative ocean CO2 uptake, (b) effect of calcification feedback (CAL-REF), and effects of ballast feedbacks in BAL1 (BAL1-CAL) and BAL2 (BAL2-CAL) on cumulative ocean CO2 uptake at year 3500. Also shown are the total effects of calcification feedback and ballast feedbacks in BAL1 (BAL1-REF) and BAL2 (BAL2-REF) simulations. Refer to Table 1 for detailed configurations of different model versions.

  • Figure 7

    (a) Model-simulated time-depth distribution of alkalinity concentration, and impacts of (b) calcification effects and (c) CO2-induced warming on model-simulated latitude-depth distribution of ALK. In (b) and (c), results shown are the differences in the simulated change (relative to 1800) at year 3500 of ALK (∆ALK3500–1800) between (b) simulations CAL and REF, and (c) CAL simulations with and without the inclusion of CO2-induced warming. Refer to Table 1 for detailed configurations of different model versions. These figures were generated using software UV-CDAT (http://uvcdat.llnl.gov/).

  • Figure 8

    Model-simulated change in global mean vertical profiles of pH at year 3500 relative to 1800 for (a) simulations of REF, CAL, BAL1, BAL2, and (b) individual effect due to changes in temperature, salinity, DIC, alkalinity induced by ballast effect, as well as the net ballast effect in BAL2 (BAL2-CAL). Refer to Table 1 for detailed configurations of different model versions.

  • Figure 9

    Model-simulated change in global mean vertical profile of POC export flux (FPOC) (a) in simulation BAL1 and (b) BAL2 at year 2300 relative to 1800. The total change in POC export flux (∆FPOC 2300–1800) can be decomposed into the change in CaCO3-related export flux of POC (∆(ρFCaCO3)2300–1800), and the change in CaCO3-unrelated export flux of POC (∆(wDD)2300–1800). Detailed configurations of different model versions are presented in Table 1.

  • Figure 10

    Model-simulated time series of (a) the effects of ballast feedbacks in simulations BAL1 and BAL2 on global mean CaCO3 production rate and (b) total CaCO3 in marine sediments. Results shown in (a) are the differences in the simulated change (relative to 1800) of CaCO3 production rate (∆CaCO3 production rate) between BAL1 and CAL, and BAL2 and CAL. Detailed configurations of different model versions are presented in Table 1.

  • Figure 11

    Effects of ballast feedbacks on model-simulated latitude-depth distribution of ((a), (c)) DIC and ((b), (d)) ALK. Results shown are the differences in the simulated change (relative to 1800) at year 3500 of DIC (∆ DIC3500–1800) and ALK (∆ALK3500–1800) between simulations ((a), (b)) BAL1 and CAL, and simulations ((c), (d)) BAL2 and CAL. Refer to Table 1 for detailed configurations of different model versions. These figures were generated using software UV-CDAT (http://uvcdat.llnl.gov/).

  • Figure 12

    Effects of ballast feedback on model-simulated time-depth distribution of ((a), (c), (e), (g)) [O2] and ((b), (d), (f), (h)) [PO43–]. Results shown are the differences in the simulated change (relative to 1800) of [O2] (∆[O2]) and [PO43–] (∆[PO43–]) between ((a)–(d)) BAL1 and CAL, and ((e)–(h)) BAL2 and CAL. Refer to Table 1 for detailed configurations of different model versions. These figures were generated using software UV-CDAT (http://uvcdat.llnl.gov/).

  • Figure 13

    Effects of ballast feedback on model-simulated latitude-depth distribution of ((a), (c), (e), (g)) [O2], and ((b), (d), (f), (h)) [PO43–]. Results shown are the differences in the simulated change (relative to 1800) at year 2600 of [O2] (∆[O2]2600–1800) and [PO43–] (∆[PO43–]2600–1800) between ((a)–(d)) BAL1 and CAL, and ((e)–(h)) BAL2 and CAL. Refer to Table 1 for detailed configurations of different model versions. These figures were generated using software UV-CDAT (http://uvcdat.llnl.gov/).

  • Figure 14

    Model-simulated effect of calcification feedback (CAL-REF), and effects of ballast feedbacks in BAL1 (BAL1-CAL) and BAL2 (BAL2-CAL) on cumulative ocean CO2 uptake at year ((a), (b)) 2000, ((c), (d)) 2300, and ((e), (f)) 2800. Results shown are ((a), (c), (e)) the absolute value, and ((b), (d), (f)) the percentage changes of the corresponding effects ((CAL-REF)/REF, (BAL1-CAL)/CAL, (BAL2-CAL)/CAL)). Also shown are the total effects of calcification feedback and ballast feedbacks in BAL1 (BAL1-REF) and BAL2 (BAL2-REF) simulations, and their percentage changes ((BAL1-REF)/REF, (BAL2-REF)/REF). Refer to Table 1 for detailed configurations of different model versions.

  • Figure 15

    Model-simulated effect of calcification feedback (CAL-REF), and effects of ballast feedbacks in BAL1 (BAL1-CAL) and BAL2 (BAL2-CAL) on global mean sea surface pH at year ((a), (b)) 2000, ((c), (d)) 2300, and ((e), (f)) 2800. Results shown are ((a), (c), (e)) the absolute value, and ((b), (d), (f)) the percentage changes of the corresponding effects ((CAL-REF)/REF, (BAL1-CAL)/CAL, (BAL2-CAL)/CAL)). Also shown are the total effects of calcification feedback and ballast feedbacks in BAL1 (BAL1-REF) and BAL2 (BAL2-REF) simulations, and their percentage changes ((BAL1-REF)/REF, (BAL2-REF)/REF). Refer to Table 1 for detailed configurations of different model versions.

  • Table 1   Configurations of different UVic model versions used in this study

    REF

    CAL

    BAL1

    BAL2

    RCaCO3/POC=0.0180

    Yes

    No

    No

    No

    RCaCO3/POC=R0CaCO3/POC(ΩC1)η

    (calcification effect)

    No

    Yes

    Yes

    Yes

    R0CaCO3/POC

    0.0038

    0.0038

    0.0038

    η

    1.09

    1.09

    1.09

    FPOC=wDD

    Yes

    Yes

    No

    No

    FPOC=wDD+ρ+FCaCO3

    (ballast effect)

    No

    No

    Yes

    Yes

    ρ

    0.045

    0.083

    Note that whether a specific process is included in each model version is indicated by the mark of “Yes” or “No” here. Numerical values represent the parameter values used in each corresponding parameterization scheme.

  • Table 2   Model-simulated ocean CO uptake for each simulation, accumulated during preindustrial time–2011 and averaged during the 1980s, 1990s, 2000s, as well as the decade since 2002

    Preindustrial–2011 cumulative

    (Pg C)

    1980–1989 average

    (Pg C yr–1)

    1990–1999 average

    (Pg C yr–1)

    2000–2009 average

    (Pg C yr–1)

    2002–2011 average

    (Pg C yr–1)

    REF

    153

    1.9

    2.2

    2.5

    2.5

    CAL

    157

    2.0

    2.3

    2.6

    2.6

    BAL1

    154

    1.9

    2.3

    2.5

    2.6

    BAL2

    153

    1.9

    2.3

    2.5

    2.6

    IPCC AR5

    155±30

    2.0±0.7

    2.2±0.7

    2.3±0.7

    2.4±0.7

    Modeled results are compared with the observational estimates summarized in IPCC AR5, which present uncertainties as 90% confidence intervals (see Table 6.1 in Ciais et al., 2013).

  • Table 3   Model-simulated changes in key ocean biogeochemistry fields between year 3500 and 1800

    REF

    CAL

    BAL1

    BAL2

    Cumulative ocean CO2 uptake (Pg C)

    2041

    2670

    2539

    2490

    Atmospheric CO2 (ppm)

    1491

    1171

    1238

    1263

    SAT (°C)

    8.9

    8.2

    8.4

    8.5

    Sea surface pH

    –0.72

    –0.59

    –0.61

    –0.62

    Sea surface [CO32–] (μmol kg–1)

    –156

    –127

    –132

    –135

    Sea surface ΩC

    –3.2

    –3.1

    –3.0

    –3.7

    Sea surface alkalinity (μmol kg–1)

    –156

    108

    69

    50

    [O2] (~180–300 m) (μmol kg–1)

    –39

    –37

    –38

    –39

    [O2] (~1100–3200 m) (μmol kg–1)

    –35

    –35

    –30

    –27

    Results are shown for the four simulations corresponding to the four parameterizations (Table1).

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