Regional and Global Patterns of Apparent Organic Matter Reactivity in Marine Sediments

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F23%3A10477206" target="_blank" >RIV/00216208:11310/23:10477206 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=cZgMt8XWMY" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=cZgMt8XWMY</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2022GB007636" target="_blank" >10.1029/2022GB007636</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Regional and Global Patterns of Apparent Organic Matter Reactivity in Marine Sediments

Popis výsledku v původním jazyce

Organic matter (OM) degradation in marine sediments is fundamental to understanding and constraining global biogeochemical cycling, whereby OM reactivity is at its core. Here, we use benthic diffusive oxygen uptake (DOU) rates as a proxy for OM reactivity. We apply an analytical diagenetic model to inversely determine OM reactivities in marine sediments (i.e., Reactive Continuum Model parameters a and.) using data sets of global DOU, surface sediment OM contents, and seafloor boundary conditions. Simulated oxygen depth profiles show good agreement with observations, increasing confidence in our reactivity estimates. Inversely determined reactivities vary over orders of magnitude between individual sites ranging from high (k = 0.252 year (-1)) for sediments in the Polar region to extremely low (k = 7.96 center dot 10(-5) year(-1)) in South Pacific. Our findings highlight the heterogeneity of OM reactivities, revealing regional patterns that broadly agree with observations and prior assessments. In general, high benthic reactivity can be linked to limited pelagic OM degradation favored by either a rapid vertical or lateral OM transport to the sediment or environmental factors, such as low oxygen concentrations or low temperature, slowing pelagic OM degradation. Finally, we develop a set of transfer functions that allow estimating OM reactivity as a function of DOU, OM content and water depths, and use one to derive the first global maps of benthic OM reactivity based on two global DOU maps. Despite the inherent observational biases in the data sets, our results provide a good first-order estimate of the apparent benthic OM reactivity agreeing with our current mechanistic understanding and observations.

Název v anglickém jazyce

Regional and Global Patterns of Apparent Organic Matter Reactivity in Marine Sediments

Popis výsledku anglicky

Organic matter (OM) degradation in marine sediments is fundamental to understanding and constraining global biogeochemical cycling, whereby OM reactivity is at its core. Here, we use benthic diffusive oxygen uptake (DOU) rates as a proxy for OM reactivity. We apply an analytical diagenetic model to inversely determine OM reactivities in marine sediments (i.e., Reactive Continuum Model parameters a and.) using data sets of global DOU, surface sediment OM contents, and seafloor boundary conditions. Simulated oxygen depth profiles show good agreement with observations, increasing confidence in our reactivity estimates. Inversely determined reactivities vary over orders of magnitude between individual sites ranging from high (k = 0.252 year (-1)) for sediments in the Polar region to extremely low (k = 7.96 center dot 10(-5) year(-1)) in South Pacific. Our findings highlight the heterogeneity of OM reactivities, revealing regional patterns that broadly agree with observations and prior assessments. In general, high benthic reactivity can be linked to limited pelagic OM degradation favored by either a rapid vertical or lateral OM transport to the sediment or environmental factors, such as low oxygen concentrations or low temperature, slowing pelagic OM degradation. Finally, we develop a set of transfer functions that allow estimating OM reactivity as a function of DOU, OM content and water depths, and use one to derive the first global maps of benthic OM reactivity based on two global DOU maps. Despite the inherent observational biases in the data sets, our results provide a good first-order estimate of the apparent benthic OM reactivity agreeing with our current mechanistic understanding and observations.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10608 - Biochemistry and molecular biology

Projekt

—

Návaznosti

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

Global Biogeochemical Cycles

ISSN

0886-6236

e-ISSN

1944-9224

Svazek periodika

37

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

25

Strana od-do

e2022GB007636

Kód UT WoS článku

001053519900001

EID výsledku v databázi Scopus

2-s2.0-85168567468