Global database of surface ocean particulate organic carbon export fluxes diagnosed from the &amp;lt;sup&amp;gt;234&amp;lt;/sup&amp;gt;Th technique

Moigne, Frédéric A.C. Le; Henson, Stephanie A.; Sanders, Richard J.; Madsen, E.

doi:10.5194/essdd-6-163-2013

Cited by 23 publications

(32 citation statements)

References 81 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(2013) dataset may include more studies from diatom-rich ecosystems with high POC: 234 Th organic particles, such as observed by (Buesseler, 1998; not included in Le Moigne et al 2013), driving some of the discrepancy between our observations and POC fluxes reported by .…”

Section: Comparison Of Export Fluxes To Previous Studiescontrasting

confidence: 38%

“…There have been far fewer estimates of 234 Th-derived biomineral export fluxes Sanders et al, 2010;Le Moigne et al, 2012;Le Moigne et al, 2013). BSi and PIC fluxes observed during GB1 and GB2 are within the range previously observed during the Crozex study by the Crozet islands , the site of station GB2-27.…”

Section: Comparison Of Export Fluxes To Previous Studiesmentioning

confidence: 85%

See 1 more Smart Citation

Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles

Rosengard¹

2017

View full text Add to dashboard Cite

Particulate organic carbon (POC) in the ocean and mobilized by rivers on land transfers ~0.1% of global primary productivity to the deep ocean sediments. This small fraction regulates the long-term carbon cycle by removing carbon dioxide from the atmosphere for centuries to millennia. This thesis investigates mechanisms of POC transfer to the deep ocean by analyzing particles collected in transit through two globally significant carbon reservoirs: the Southern Ocean and the Amazon River Basin. These endeavors test the hypothesis that organic matter composition controls the recycling and transfer efficiency of POC to the deep ocean, and illustrate new applications for ramped pyrolysis/oxidation (RPO), a growing method of POC characterization by thermal stability. By coupling RPO to stable and radiocarbon isotope analyses of riverine POC, I quantify three thermally distinct soil organic carbon pools mobilized by the Amazon River, and evaluate the degradability and fate of these different pools during transport to the coastal Atlantic Ocean. More directly, RPO analyses of marine samples suggest that POC transfer in the water column is in fact selective. Observations of consistent biomolecular changes that accompany transport of phytoplankton-derived organic matter to depth across the Southern Ocean support the argument for preferential degradation of specific POC pools in the water column. Combining discussions of POC recycling and transfer across both marine and terrestrial systems offer new perspectives of thermal stability as a proxy for diagenetic stability and POC degradation state. The challenges of interpreting RPO data in these two environments set the stage for applying the technique to more controlled experiments that trace POC from source to long-term sink.

show abstract

Section: Comparison Of Export Fluxes To Previous Studiescontrasting

confidence: 38%

Section: Comparison Of Export Fluxes To Previous Studiesmentioning

confidence: 85%

Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles

Rosengard¹

2017

View full text Add to dashboard Cite

show abstract

“…3 in the North Atlantic Ocean) includes POC observations. Observed POC fluxes are from Dunne et al (2005), Gehlen et al (2006), andLe Moigne (2013). In these datasets, data have been obtained from sediment traps and/or 234 Th.…”

Section: Observationsmentioning

confidence: 99%

Variable reactivity of particulate organic matter in a global ocean biogeochemical model

et al. 2017

View full text Add to dashboard Cite

Abstract. The marine biological carbon pump is dominated by the vertical transfer of particulate organic carbon (POC) from the surface ocean to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the ocean. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which, such as iron, are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. However, this variable reactivity of POC has never been extensively considered, especially in modelling studies. Here, we introduced in the global ocean biogeochemical model NEMO-PISCES a description of the variable composition of POC based on the theoretical reactivity continuum model proposed by Boudreau and Ruddick (1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the ocean's interior by 1 to 2 orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of 2, which is in better agreement with global estimates of the sediment oxygen demand. The impact on the major macronutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: vertical gradients in Fe are milder in the upper ocean, which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine biogeochemical cycles which advocates for more dedicated in situ and laboratory experiments.

show abstract

“…These data are a significant contribution to the rapidly growing global 234 Th data set (Le Moigne et al, 2013). In this work we describe the variability in upper ocean export fluxes and derive estimates of carbon export in the Atlantic Ocean.…”

Section: Introductionmentioning

confidence: 99%

Thorium-234 as a tracer of particle dynamics and upper ocean export in the Atlantic Ocean

Owens

Pike

Buesseler

2015

Deep Sea Research Part II: Topical Studies in Oceanography

102

View full text Add to dashboard Cite

a b s t r a c tThe flux of sinking particles is an important removal mechanism of carbon and other chemical species from the surface ocean as part of the biological pump. Euphotic zone export of 234 Th was measured on GEOTRACES transects of the Atlantic Ocean to evaluate basin-scale export variability. High-resolution sampling through the entire water-column allowed for the identification of unique 234 Th features in intermediate and deep waters. These data will be important for describing distributions and estimating the fluxes of trace elements measured by other investigators in the GEOTRACES program. This extensive data set will also be useful when combined with other particulate and radioisotope data for improving our understanding of particle cycling and the relation of particle flux to particle composition and abundance.

show abstract

Global database of surface ocean particulate organic carbon export fluxes diagnosed from the <sup>234</sup>Th technique

Cited by 23 publications

References 81 publications

Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles

Novel analytical strategies for tracing the organic carbon cycle in marine and riverine particles

Variable reactivity of particulate organic matter in a global ocean biogeochemical model

Thorium-234 as a tracer of particle dynamics and upper ocean export in the Atlantic Ocean

Contact Info

Product

Resources

About