Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean
Chromophoric dissolved organic matter (CDOM) ubiquitously occurs in marine environments and plays a significant role in the marine biogeochemical cycles. Basin scale distributions of CDOM have recently been surveyed in the global ocean and indicate that quantity and quality of oceanic CDOM are mainl...
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ftdoajarticles:oai:doaj.org/article:5be506b27b584f8e85de270706af365f 2023-05-15T18:28:05+02:00 Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean Y. Yamashita Y. Nosaka K. Suzuki H. Ogawa K. Takahashi H. Saito 2013-11-01T00:00:00Z https://doi.org/10.5194/bg-10-7207-2013 https://doaj.org/article/5be506b27b584f8e85de270706af365f EN eng Copernicus Publications http://www.biogeosciences.net/10/7207/2013/bg-10-7207-2013.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-10-7207-2013 https://doaj.org/article/5be506b27b584f8e85de270706af365f Biogeosciences, Vol 10, Iss 11, Pp 7207-7217 (2013) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2013 ftdoajarticles https://doi.org/10.5194/bg-10-7207-2013 2022-12-31T12:48:05Z Chromophoric dissolved organic matter (CDOM) ubiquitously occurs in marine environments and plays a significant role in the marine biogeochemical cycles. Basin scale distributions of CDOM have recently been surveyed in the global ocean and indicate that quantity and quality of oceanic CDOM are mainly controlled by in situ production and photobleaching. However, factors controlling the spectral parameters of CDOM in the UV region, i.e., spectral slope of CDOM determined at 275–295 nm ( S 275–295 ) and the ratio of two spectral slope parameters ( S R ); the ratio of S 275–295 to S 350–400 , have not been well documented. To evaluate the factor controlling the spectral characteristics of CDOM in the UV region in the open ocean, we determined the quantitative and qualitative characteristics of CDOM in the subarctic and subtropical surface waters (5–300 m) of the western North Pacific. Absorption coefficients at 320 nm in the subarctic region were higher than those in the subtropical region throughout surface waters, suggesting that magnitudes of photobleaching were different between the two regions. The values of S 275–295 and S R were also higher in the subtropical region than the subarctic region. The dark microbial incubation showed biodegradation of DOM little affected S 275–295 , but slightly decreased S R . On the other hand, increases in S 275–295 and relative stableness of S R were observed during photo-irradiation incubations respectively. These experimental results indicated that photobleaching of CDOM mainly induced qualitative differences in CDOM at UV region between the subarctic and subtropical surface waters. The results of this study imply that S 275–295 can be used as a tracer of photochemical history of CDOM in the open ocean. Article in Journal/Newspaper Subarctic Directory of Open Access Journals: DOAJ Articles Pacific Biogeosciences 10 11 7207 7217 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
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Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 Y. Yamashita Y. Nosaka K. Suzuki H. Ogawa K. Takahashi H. Saito Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Chromophoric dissolved organic matter (CDOM) ubiquitously occurs in marine environments and plays a significant role in the marine biogeochemical cycles. Basin scale distributions of CDOM have recently been surveyed in the global ocean and indicate that quantity and quality of oceanic CDOM are mainly controlled by in situ production and photobleaching. However, factors controlling the spectral parameters of CDOM in the UV region, i.e., spectral slope of CDOM determined at 275–295 nm ( S 275–295 ) and the ratio of two spectral slope parameters ( S R ); the ratio of S 275–295 to S 350–400 , have not been well documented. To evaluate the factor controlling the spectral characteristics of CDOM in the UV region in the open ocean, we determined the quantitative and qualitative characteristics of CDOM in the subarctic and subtropical surface waters (5–300 m) of the western North Pacific. Absorption coefficients at 320 nm in the subarctic region were higher than those in the subtropical region throughout surface waters, suggesting that magnitudes of photobleaching were different between the two regions. The values of S 275–295 and S R were also higher in the subtropical region than the subarctic region. The dark microbial incubation showed biodegradation of DOM little affected S 275–295 , but slightly decreased S R . On the other hand, increases in S 275–295 and relative stableness of S R were observed during photo-irradiation incubations respectively. These experimental results indicated that photobleaching of CDOM mainly induced qualitative differences in CDOM at UV region between the subarctic and subtropical surface waters. The results of this study imply that S 275–295 can be used as a tracer of photochemical history of CDOM in the open ocean. |
format |
Article in Journal/Newspaper |
author |
Y. Yamashita Y. Nosaka K. Suzuki H. Ogawa K. Takahashi H. Saito |
author_facet |
Y. Yamashita Y. Nosaka K. Suzuki H. Ogawa K. Takahashi H. Saito |
author_sort |
Y. Yamashita |
title |
Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean |
title_short |
Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean |
title_full |
Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean |
title_fullStr |
Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean |
title_full_unstemmed |
Photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean |
title_sort |
photobleaching as a factor controlling spectral characteristics of chromophoric dissolved organic matter in open ocean |
publisher |
Copernicus Publications |
publishDate |
2013 |
url |
https://doi.org/10.5194/bg-10-7207-2013 https://doaj.org/article/5be506b27b584f8e85de270706af365f |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Subarctic |
genre_facet |
Subarctic |
op_source |
Biogeosciences, Vol 10, Iss 11, Pp 7207-7217 (2013) |
op_relation |
http://www.biogeosciences.net/10/7207/2013/bg-10-7207-2013.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 1726-4170 1726-4189 doi:10.5194/bg-10-7207-2013 https://doaj.org/article/5be506b27b584f8e85de270706af365f |
op_doi |
https://doi.org/10.5194/bg-10-7207-2013 |
container_title |
Biogeosciences |
container_volume |
10 |
container_issue |
11 |
container_start_page |
7207 |
op_container_end_page |
7217 |
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1766210427556986880 |