Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters
Coastal seas receive large amounts of terrestrially derived organic carbon (OC). The fate of this carbon, and its impact on the marine environment, is however poorly understood. Here we combine underway CO 2 partial pressure ( p CO 2 ) measurements with coupled 3-D hydrodynamical–biogeochemical mode...
Published in: | Biogeosciences |
---|---|
Main Authors: | , , , , , , |
Format: | Text |
Language: | English |
Published: |
2019
|
Subjects: | |
Online Access: | https://doi.org/10.5194/bg-16-863-2019 https://www.biogeosciences.net/16/863/2019/ |
id |
ftcopernicus:oai:publications.copernicus.org:bg70298 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:bg70298 2023-05-15T18:28:26+02:00 Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters Fransner, Filippa Fransson, Agneta Humborg, Christoph Gustafsson, Erik Tedesco, Letizia Hordoir, Robinson Nycander, Jonas 2019-02-20 application/pdf https://doi.org/10.5194/bg-16-863-2019 https://www.biogeosciences.net/16/863/2019/ eng eng doi:10.5194/bg-16-863-2019 https://www.biogeosciences.net/16/863/2019/ eISSN: 1726-4189 Text 2019 ftcopernicus https://doi.org/10.5194/bg-16-863-2019 2019-12-24T09:49:26Z Coastal seas receive large amounts of terrestrially derived organic carbon (OC). The fate of this carbon, and its impact on the marine environment, is however poorly understood. Here we combine underway CO 2 partial pressure ( p CO 2 ) measurements with coupled 3-D hydrodynamical–biogeochemical modelling to investigate whether remineralization of terrestrial dissolved organic carbon (tDOC) can explain CO 2 supersaturated surface waters in the Gulf of Bothnia, a subarctic estuary. We find that a substantial remineralization of tDOC and a strong tDOC-induced light attenuation dampening the primary production are required to reproduce the observed CO 2 supersaturated waters in the nearshore areas. A removal rate of tDOC of the order of 1 year, estimated in a previous modelling study in the same area, gives a good agreement between modelled and observed p CO 2 . The remineralization rate is on the same order as bacterial degradation rates calculated from published incubation experiments, suggesting that bacteria has the potential to cause this degradation. Furthermore, the observed high p CO 2 values during the ice-covered season argue against photochemical degradation as the main removal mechanism. All of the remineralized tDOC is outgassed to the atmosphere in the model, turning the northernmost part of the Gulf of Bothnia into a source of CO 2 to the atmosphere. Text Subarctic Copernicus Publications: E-Journals Biogeosciences 16 4 863 879 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Coastal seas receive large amounts of terrestrially derived organic carbon (OC). The fate of this carbon, and its impact on the marine environment, is however poorly understood. Here we combine underway CO 2 partial pressure ( p CO 2 ) measurements with coupled 3-D hydrodynamical–biogeochemical modelling to investigate whether remineralization of terrestrial dissolved organic carbon (tDOC) can explain CO 2 supersaturated surface waters in the Gulf of Bothnia, a subarctic estuary. We find that a substantial remineralization of tDOC and a strong tDOC-induced light attenuation dampening the primary production are required to reproduce the observed CO 2 supersaturated waters in the nearshore areas. A removal rate of tDOC of the order of 1 year, estimated in a previous modelling study in the same area, gives a good agreement between modelled and observed p CO 2 . The remineralization rate is on the same order as bacterial degradation rates calculated from published incubation experiments, suggesting that bacteria has the potential to cause this degradation. Furthermore, the observed high p CO 2 values during the ice-covered season argue against photochemical degradation as the main removal mechanism. All of the remineralized tDOC is outgassed to the atmosphere in the model, turning the northernmost part of the Gulf of Bothnia into a source of CO 2 to the atmosphere. |
format |
Text |
author |
Fransner, Filippa Fransson, Agneta Humborg, Christoph Gustafsson, Erik Tedesco, Letizia Hordoir, Robinson Nycander, Jonas |
spellingShingle |
Fransner, Filippa Fransson, Agneta Humborg, Christoph Gustafsson, Erik Tedesco, Letizia Hordoir, Robinson Nycander, Jonas Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters |
author_facet |
Fransner, Filippa Fransson, Agneta Humborg, Christoph Gustafsson, Erik Tedesco, Letizia Hordoir, Robinson Nycander, Jonas |
author_sort |
Fransner, Filippa |
title |
Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters |
title_short |
Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters |
title_full |
Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters |
title_fullStr |
Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters |
title_full_unstemmed |
Remineralization rate of terrestrial DOC as inferred from CO2 supersaturated coastal waters |
title_sort |
remineralization rate of terrestrial doc as inferred from co2 supersaturated coastal waters |
publishDate |
2019 |
url |
https://doi.org/10.5194/bg-16-863-2019 https://www.biogeosciences.net/16/863/2019/ |
genre |
Subarctic |
genre_facet |
Subarctic |
op_source |
eISSN: 1726-4189 |
op_relation |
doi:10.5194/bg-16-863-2019 https://www.biogeosciences.net/16/863/2019/ |
op_doi |
https://doi.org/10.5194/bg-16-863-2019 |
container_title |
Biogeosciences |
container_volume |
16 |
container_issue |
4 |
container_start_page |
863 |
op_container_end_page |
879 |
_version_ |
1766210912972177408 |