Surface fertilisation and organic matter delivery enhanced carbonate dissolution in the western South Atlantic

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F23%3A10475679" target="_blank" >RIV/00216208:11310/23:10475679 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=W6tpiScdTR" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=W6tpiScdTR</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3389/fevo.2023.1238334" target="_blank" >10.3389/fevo.2023.1238334</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Surface fertilisation and organic matter delivery enhanced carbonate dissolution in the western South Atlantic

Popis výsledku v původním jazyce

The last glacial inception was characterised by rapid changes in temperature, atmospheric pCO(2), and changes in the water mass geometry of the major ocean basins. Although several climatic feedback mechanisms have been proposed to explain the glacial/interglacial cycles witnessed in the Quaternary, the exact mechanistic responses of these processes are still under constrained. In this study we use proxies including planktonic foraminifera compositional assemblages and oxygen stable isotopes to reconstruct past changes in sea surface productivity, stratification, and carbonate dissolution. We use core SIS-249 (2,091 mbsl, western South Atlantic 30 degrees S 47 degrees W), spanning 30-110 thousand years ago (ka), and currently bathed by modern Northern Component Water. We test existing hypotheses suggesting that the orbital obliquity cycle modulates the biological pump in the study area. Spectral analysis run on our synthesised productivity proxies recognises a similar to 43 kyr-cycle, related to the obliquity cycle. We propose that the enhanced productivity is produced by two mechanisms: i) the glacial upwelling of subsurface nutrient-rich waters and, ii) the continental (wind-driven dust and riverine outflows) fertilisation of the photic zone, with the latter process being obliquity-paced. We also suggest that not only the increased organic matter export but also a change in its bioavailability (from refractory to labile) led to calcium carbonate dissolution, as the degradation of the more soluble organic matter decreased the pH of the glacial bottom water, partially dissolving the calcium carbonate. Although our correlation analyses show a strong benthic-pelagic coupling through the relation between the enhanced biological pump and carbonate dissolution (rho&lt;0.05, r=0.80), we cannot reject the potential of corrosive Southern Component Water bathing the site during the glacial. Finally, we highlight that these processes are not mutually exclusive and that both can be modulated by the obliquity cycle.

Název v anglickém jazyce

Surface fertilisation and organic matter delivery enhanced carbonate dissolution in the western South Atlantic

Popis výsledku anglicky

The last glacial inception was characterised by rapid changes in temperature, atmospheric pCO(2), and changes in the water mass geometry of the major ocean basins. Although several climatic feedback mechanisms have been proposed to explain the glacial/interglacial cycles witnessed in the Quaternary, the exact mechanistic responses of these processes are still under constrained. In this study we use proxies including planktonic foraminifera compositional assemblages and oxygen stable isotopes to reconstruct past changes in sea surface productivity, stratification, and carbonate dissolution. We use core SIS-249 (2,091 mbsl, western South Atlantic 30 degrees S 47 degrees W), spanning 30-110 thousand years ago (ka), and currently bathed by modern Northern Component Water. We test existing hypotheses suggesting that the orbital obliquity cycle modulates the biological pump in the study area. Spectral analysis run on our synthesised productivity proxies recognises a similar to 43 kyr-cycle, related to the obliquity cycle. We propose that the enhanced productivity is produced by two mechanisms: i) the glacial upwelling of subsurface nutrient-rich waters and, ii) the continental (wind-driven dust and riverine outflows) fertilisation of the photic zone, with the latter process being obliquity-paced. We also suggest that not only the increased organic matter export but also a change in its bioavailability (from refractory to labile) led to calcium carbonate dissolution, as the degradation of the more soluble organic matter decreased the pH of the glacial bottom water, partially dissolving the calcium carbonate. Although our correlation analyses show a strong benthic-pelagic coupling through the relation between the enhanced biological pump and carbonate dissolution (rho&lt;0.05, r=0.80), we cannot reject the potential of corrosive Southern Component Water bathing the site during the glacial. Finally, we highlight that these processes are not mutually exclusive and that both can be modulated by the obliquity cycle.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Frontiers in Ecology and Evolution

ISSN

2296-701X

e-ISSN

2296-701X

Svazek periodika

11

Číslo periodika v rámci svazku

November

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

14

Strana od-do

1238334

Kód UT WoS článku

001105255900001

EID výsledku v databázi Scopus

2-s2.0-85177225274