Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation
The composition and cycling dynamics of marine dissolved organic carbon (DOC) have received increased interest in recent years; however, little research has focused on the refractory, low molecular weight (LMW) component that makes up the majority of this massive C pool. In this study, we measured s...
Published in: | Global Biogeochemical Cycles |
---|---|
Main Authors: | , , , , , |
Language: | unknown |
Published: |
2021
|
Subjects: | |
Online Access: | http://www.osti.gov/servlets/purl/1658694 https://www.osti.gov/biblio/1658694 https://doi.org/10.1029/2020gb006547 |
id |
ftosti:oai:osti.gov:1658694 |
---|---|
record_format |
openpolar |
spelling |
ftosti:oai:osti.gov:1658694 2023-07-30T04:05:32+02:00 Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation Broek, Taylor A. B. Walker, Brett D. Guilderson, Thomas P. Vaughn, John S. Mason, Harris E. McCarthy, Matthew D. 2021-06-08 application/pdf http://www.osti.gov/servlets/purl/1658694 https://www.osti.gov/biblio/1658694 https://doi.org/10.1029/2020gb006547 unknown http://www.osti.gov/servlets/purl/1658694 https://www.osti.gov/biblio/1658694 https://doi.org/10.1029/2020gb006547 doi:10.1029/2020gb006547 58 GEOSCIENCES 2021 ftosti https://doi.org/10.1029/2020gb006547 2023-07-11T09:46:38Z The composition and cycling dynamics of marine dissolved organic carbon (DOC) have received increased interest in recent years; however, little research has focused on the refractory, low molecular weight (LMW) component that makes up the majority of this massive C pool. In this study, we measured stable isotopic (δ 13 C), radioisotopic (Δ 14 C), and compositional (C/N, 13 C solid-state NMR) properties of separately isolated high molecular weight (HMW) and LMW DOC fractions collected using a coupled ultrafiltration and solid phase extraction approach from throughout the water column in the North Central Pacific and Central North Atlantic. The selective isolation of LMW DOC material allowed the first investigation of the composition and cycling of a previously elusive fraction of the DOC pool. The structural composition of the LMW DOC material was homogeneous throughout the water column and closely matched carboxylic-rich alicyclic material that has been proposed as a major component of the marine refractory DOC pool. Examination of offsets in the measured parameters between the deep waters of the two basins provides the first direct assessment of changes in the properties of this material with aging and utilization during ocean circulation. While our direct measurements largely confirm hypotheses regarding the relative recalcitrance of HMW and LMW DOC, we also demonstrate a number of novel observations regarding the removal and addition of DOC during global ocean circulation, including additions of fresh carbohydrate-like HMW DOC to the deep ocean and large-scale removal of both semilabile HMW and recalcitrant LMW DOC. Other/Unknown Material North Atlantic SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Pacific Global Biogeochemical Cycles 34 6 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
58 GEOSCIENCES |
spellingShingle |
58 GEOSCIENCES Broek, Taylor A. B. Walker, Brett D. Guilderson, Thomas P. Vaughn, John S. Mason, Harris E. McCarthy, Matthew D. Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation |
topic_facet |
58 GEOSCIENCES |
description |
The composition and cycling dynamics of marine dissolved organic carbon (DOC) have received increased interest in recent years; however, little research has focused on the refractory, low molecular weight (LMW) component that makes up the majority of this massive C pool. In this study, we measured stable isotopic (δ 13 C), radioisotopic (Δ 14 C), and compositional (C/N, 13 C solid-state NMR) properties of separately isolated high molecular weight (HMW) and LMW DOC fractions collected using a coupled ultrafiltration and solid phase extraction approach from throughout the water column in the North Central Pacific and Central North Atlantic. The selective isolation of LMW DOC material allowed the first investigation of the composition and cycling of a previously elusive fraction of the DOC pool. The structural composition of the LMW DOC material was homogeneous throughout the water column and closely matched carboxylic-rich alicyclic material that has been proposed as a major component of the marine refractory DOC pool. Examination of offsets in the measured parameters between the deep waters of the two basins provides the first direct assessment of changes in the properties of this material with aging and utilization during ocean circulation. While our direct measurements largely confirm hypotheses regarding the relative recalcitrance of HMW and LMW DOC, we also demonstrate a number of novel observations regarding the removal and addition of DOC during global ocean circulation, including additions of fresh carbohydrate-like HMW DOC to the deep ocean and large-scale removal of both semilabile HMW and recalcitrant LMW DOC. |
author |
Broek, Taylor A. B. Walker, Brett D. Guilderson, Thomas P. Vaughn, John S. Mason, Harris E. McCarthy, Matthew D. |
author_facet |
Broek, Taylor A. B. Walker, Brett D. Guilderson, Thomas P. Vaughn, John S. Mason, Harris E. McCarthy, Matthew D. |
author_sort |
Broek, Taylor A. B. |
title |
Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation |
title_short |
Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation |
title_full |
Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation |
title_fullStr |
Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation |
title_full_unstemmed |
Low Molecular Weight Dissolved Organic Carbon: Aging, Compositional Changes, and Selective Utilization During Global Ocean Circulation |
title_sort |
low molecular weight dissolved organic carbon: aging, compositional changes, and selective utilization during global ocean circulation |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1658694 https://www.osti.gov/biblio/1658694 https://doi.org/10.1029/2020gb006547 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://www.osti.gov/servlets/purl/1658694 https://www.osti.gov/biblio/1658694 https://doi.org/10.1029/2020gb006547 doi:10.1029/2020gb006547 |
op_doi |
https://doi.org/10.1029/2020gb006547 |
container_title |
Global Biogeochemical Cycles |
container_volume |
34 |
container_issue |
6 |
_version_ |
1772817519609905152 |