On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean
Nitrous oxide (N2O) is a powerful greenhouse gas principally produced by nitrification and denitrification in the marine environment. Observations were made in the eastern South Pacific (ESP), between 10° and 60°S, and ~75°–88°W, from intermediate waters targeting Antarctic Intermediate Water (AAIW)...
Published in: | Frontiers in Marine Science |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Frontiers
2017
|
Subjects: | |
Online Access: | https://oceanrep.geomar.de/id/eprint/37646/ https://oceanrep.geomar.de/id/eprint/37646/1/fmars-04-00024.pdf https://doi.org/10.3389/fmars.2017.00024 |
id |
ftoceanrep:oai:oceanrep.geomar.de:37646 |
---|---|
record_format |
openpolar |
spelling |
ftoceanrep:oai:oceanrep.geomar.de:37646 2023-05-15T13:52:13+02:00 On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean Carrasco, Cristina Karstensen, Johannes Farias, Laura 2017-02-03 text https://oceanrep.geomar.de/id/eprint/37646/ https://oceanrep.geomar.de/id/eprint/37646/1/fmars-04-00024.pdf https://doi.org/10.3389/fmars.2017.00024 en eng Frontiers https://oceanrep.geomar.de/id/eprint/37646/1/fmars-04-00024.pdf Carrasco, C., Karstensen, J. and Farias, L. (2017) On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean. Open Access Frontiers in Marine Science, 4 . Art.Nr. 24. DOI 10.3389/fmars.2017.00024 <https://doi.org/10.3389/fmars.2017.00024>. doi:10.3389/fmars.2017.00024 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2017 ftoceanrep https://doi.org/10.3389/fmars.2017.00024 2023-04-07T15:32:48Z Nitrous oxide (N2O) is a powerful greenhouse gas principally produced by nitrification and denitrification in the marine environment. Observations were made in the eastern South Pacific (ESP), between 10° and 60°S, and ~75°–88°W, from intermediate waters targeting Antarctic Intermediate Water (AAIW) at potential density of 27.0–27.1 kg m−3. Between 60° and 20°S, a gradual equatorward increase of N2O from 8 to 26 nmol L−1 was observed at density 27.0–27.1 kg m−3 where AAIW penetrates. Positive correlations were found between apparent N2O production (ΔN2O) and O2 utilization (AOU), and between ΔN2O and NO−3, which suggested that local N2O production is predominantly produced by nitrification. Closer to the equator, between 20° and 10°S at AAIW core, a strong N2O increase up to 75 nmol L−1 was observed. Because negative correlations were found between ΔN2O vs. NO−3 and ΔN2O vs. N* (a Nitrogen deficit index) and because ΔN2O and AOU do not follow a linear trend, we suspect that, in addition to nitrification, denitrification also takes place in N2O cycling. By making use of water mass mixing analyses, we show that an increase in N2O occurs in the region where high oxygen from AAIW merges with low oxygen from Equatorial Subsurface Water (ESSW), creating favorable conditions for local N2O production. We conclude that the non-linearity in the relationship between N2O and O2 is a result of mixing between two water masses with very different source characteristics, paired with the different time frames of nitrification and denitrification processes that impact water masses en route before they finally meet and mix in the ESP region. Article in Journal/Newspaper Antarc* Antarctic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Pacific Frontiers in Marine Science 4 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Nitrous oxide (N2O) is a powerful greenhouse gas principally produced by nitrification and denitrification in the marine environment. Observations were made in the eastern South Pacific (ESP), between 10° and 60°S, and ~75°–88°W, from intermediate waters targeting Antarctic Intermediate Water (AAIW) at potential density of 27.0–27.1 kg m−3. Between 60° and 20°S, a gradual equatorward increase of N2O from 8 to 26 nmol L−1 was observed at density 27.0–27.1 kg m−3 where AAIW penetrates. Positive correlations were found between apparent N2O production (ΔN2O) and O2 utilization (AOU), and between ΔN2O and NO−3, which suggested that local N2O production is predominantly produced by nitrification. Closer to the equator, between 20° and 10°S at AAIW core, a strong N2O increase up to 75 nmol L−1 was observed. Because negative correlations were found between ΔN2O vs. NO−3 and ΔN2O vs. N* (a Nitrogen deficit index) and because ΔN2O and AOU do not follow a linear trend, we suspect that, in addition to nitrification, denitrification also takes place in N2O cycling. By making use of water mass mixing analyses, we show that an increase in N2O occurs in the region where high oxygen from AAIW merges with low oxygen from Equatorial Subsurface Water (ESSW), creating favorable conditions for local N2O production. We conclude that the non-linearity in the relationship between N2O and O2 is a result of mixing between two water masses with very different source characteristics, paired with the different time frames of nitrification and denitrification processes that impact water masses en route before they finally meet and mix in the ESP region. |
format |
Article in Journal/Newspaper |
author |
Carrasco, Cristina Karstensen, Johannes Farias, Laura |
spellingShingle |
Carrasco, Cristina Karstensen, Johannes Farias, Laura On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean |
author_facet |
Carrasco, Cristina Karstensen, Johannes Farias, Laura |
author_sort |
Carrasco, Cristina |
title |
On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean |
title_short |
On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean |
title_full |
On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean |
title_fullStr |
On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean |
title_full_unstemmed |
On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean |
title_sort |
on the nitrous oxide accumulation in intermediate waters of the eastern south pacific ocean |
publisher |
Frontiers |
publishDate |
2017 |
url |
https://oceanrep.geomar.de/id/eprint/37646/ https://oceanrep.geomar.de/id/eprint/37646/1/fmars-04-00024.pdf https://doi.org/10.3389/fmars.2017.00024 |
geographic |
Antarctic Pacific |
geographic_facet |
Antarctic Pacific |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
https://oceanrep.geomar.de/id/eprint/37646/1/fmars-04-00024.pdf Carrasco, C., Karstensen, J. and Farias, L. (2017) On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean. Open Access Frontiers in Marine Science, 4 . Art.Nr. 24. DOI 10.3389/fmars.2017.00024 <https://doi.org/10.3389/fmars.2017.00024>. doi:10.3389/fmars.2017.00024 |
op_rights |
cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3389/fmars.2017.00024 |
container_title |
Frontiers in Marine Science |
container_volume |
4 |
_version_ |
1766256489316483072 |