A dynamic-flow carbon-cycle box model and high-latitude sensitivity

Mitchell, Emily; Peacock, Synte; Restrepo, Juan M.

doi:10.3402/tellusb.v58i4.16886

Cited by 2 publications

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“…MF ij of ADV was estimated to be 0.87 Sv using the volume of the Izu-Ogasawara Trench (below 6000 m) derived from the ETOPO 1 model, as well as the renewal time of ~ 5 years 37 . MF ij of MIX was estimated using a similar approach to that adopted by Lane et al 38 . Generally, eddy-mixing coefficient multiplied by the interface area of boxes is divided by the distance between box centers.…”

Section: Methodsmentioning

confidence: 99%

Sedimentary supply of humic-like fluorescent dissolved organic matter and its implication for chemoautotrophic microbial activity in the Izu-Ogasawara Trench

Shigemitsu

Yokokawa

Uchida

et al. 2021

Sci Rep

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Microbial community structure in the hadal water is reported to be different from that in the upper abyssal water. However, the mechanism governing the difference has not been fully understood. In this study, we investigate the vertical distributions of humic-like fluorescent dissolved organic matter (FDOMH), chemoautotrophic production, apparent oxygen utilization (AOU), and N* in the Izu-Ogasawara Trench. In the upper abyssal waters (< 6000 m), FDOMH has a significantly positive correlation with AOU; FDOMH deviates from the relationship and increases with depth without involving the increment of AOU in the hadal waters. This suggests that FDOMH is transferred from the sediments to the hadal waters through pore water, while the FDOMH is produced in situ in the upper abyssal waters. Chemoautotrophic production and N* increases and decreases with depth in the hadal waters, respectively. This corroborates the effluxes of dissolved substances, including dissolved organic matter and electron donors from sediments, which fuels the heterotrophic/chemoautotrophic microbial communities in the hadal waters. A simple box model analysis reveals that the funnel-like trench topography facilitates the increase in dissolved substances with depth in the hadal waters, which might contribute to the unique microbiological community structure in these waters.

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Section: Methodsmentioning

confidence: 99%

Sedimentary supply of humic-like fluorescent dissolved organic matter and its implication for chemoautotrophic microbial activity in the Izu-Ogasawara Trench

Shigemitsu

Yokokawa

Uchida

et al. 2021

Sci Rep

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“…Former comparisons of simulated atmospheric CO 2 to changes in high latitude processes suggested that more complex models are in some aspects less sensitive on SO processes than simpler carbon cycle box models (Archer et al, 2000b;Broecker et al, 1999). However, the comparison of completely different types of models is not straightforward (Lane et al, 2006) and a given model maybe high latitude sensitive to certain parameters but not to others. The challenge remains to explain the low glacial CO 2 in a self-consistent 3-dimensional dynamical model setting.…”

Section: Introductionmentioning

confidence: 99%

The role of Southern Ocean processes in orbital and millennial CO2 variations – A synthesis

Fischer

Schmitt

Lüthi

et al. 2010

Quaternary Science Reviews

126

133

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a b s t r a c tRecent progress in the reconstruction of atmospheric CO 2 records from Antarctic ice cores has allowed for the documentation of natural CO 2 variations on orbital time scales over the last up to 800,000 years and for the resolution of millennial CO 2 variations during the last glacial cycle in unprecedented detail. This has shown that atmospheric CO 2 varied within natural bounds of approximately 170-300 ppmv but never reached recent CO 2 concentrations caused by anthropogenic CO 2 emissions. In addition, the natural atmospheric CO 2 concentrations show an extraordinary correlation with Southern Ocean climate changes, pointing to a significant (direct or indirect) influence of climatic and environmental changes in the Southern Ocean region on atmospheric CO 2 concentrations.Here, we compile recent ice core and marine sediment records of atmospheric CO 2 , temperature and environmental changes in the Southern Ocean region, as well as carbon cycle model experiments, in order to quantify the effect of potential Southern Ocean processes on atmospheric CO 2 related to these orbital and millennial changes. This shows that physical and biological changes in the SO are able to explain substantial parts of the glacial/interglacial CO 2 change, but that none of the single processes is able to explain this change by itself. In particular, changes in the Southern Ocean related to changes in the surface buoyancy flux, which in return is controlled by the waxing and waning of sea ice may favorably explain the high correlation of CO 2 and Antarctic temperature on orbital and millennial time scales. In contrast, the changes of the position and strength of the westerly wind field were most likely too small to explain the observed changes in atmospheric CO 2 or may even have increased atmospheric CO 2 in the glacial. Also iron fertilization of the marine biota in the Southern Ocean contributes to a glacial drawdown of CO 2 but turns out to be limited by other factors than the total dust input such as bioavailability of iron or macronutrient supply.

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A dynamic-flow carbon-cycle box model and high-latitude sensitivity

Cited by 2 publications

References 0 publications

Sedimentary supply of humic-like fluorescent dissolved organic matter and its implication for chemoautotrophic microbial activity in the Izu-Ogasawara Trench

Sedimentary supply of humic-like fluorescent dissolved organic matter and its implication for chemoautotrophic microbial activity in the Izu-Ogasawara Trench

The role of Southern Ocean processes in orbital and millennial CO2 variations – A synthesis

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