Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b)
Figure 4. Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components...
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ftdatacite:10.6084/m9.figshare.1011775 2023-05-15T15:18:04+02:00 Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b) Laurion, Isabelle Mladenov, Natalie 2013 https://dx.doi.org/10.6084/m9.figshare.1011775 https://iop.figshare.com/articles/figure/_Excitation_emission_matrices_EEMs_of_fluorescence_of_the_two_experimental_ponds_at_the_beginning_em/1011775 unknown IOP Publishing Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY Environmental Science Image Figure graphic ImageObject 2013 ftdatacite https://doi.org/10.6084/m9.figshare.1011775 2021-11-05T12:55:41Z Figure 4. Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b). Abstract The abundant thaw lakes and ponds in the circumarctic receive a new pool of organic carbon as permafrost peat soils degrade, which can be exposed to significant irradiance that potentially increases as climate warms and ice cover shortens. Exposure to sunlight is known to accelerate the transformation of dissolved organic matter (DOM) into molecules that can be more readily used by microbes. We sampled the water from two common classes of ponds found in the ice-wedge system of continuous permafrost regions of Canada, polygonal and runnel ponds, and followed the transformation of DOM over 12 days by looking at dissolved organic carbon (DOC) concentration and DOM absorption and fluorescence properties. The results indicate a relatively fast decay of color (3.4 and 1.6% loss d −1 of absorption at 320 nm for the polygonal and runnel pond, respectively) and fluorescence (6.1 and 8.3% loss d −1 of total fluorescent components, respectively) at the pond surface, faster in the case of humic-like components, but insignificant losses of DOC over the observed period. This result indicates that direct DOM mineralization (photochemical production of CO 2 ) is apparently minor in thaw ponds compared to the photochemical transformation of DOM into less chromophoric and likely more labile molecules with a greater potential for microbial mineralization. Therefore, DOM photolysis in arctic thaw ponds can be considered as a catalytic mechanism, accelerating the microbial turnover of mobilized organic matter from thawing permafrost and the production of greenhouse gases, especially in the most shallow ponds. Under a warming climate, this mechanism will intensify as summers lengthen. Still Image Arctic Ice permafrost wedge* DataCite Metadata Store (German National Library of Science and Technology) Arctic Canada |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
unknown |
topic |
Environmental Science |
spellingShingle |
Environmental Science Laurion, Isabelle Mladenov, Natalie Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b) |
topic_facet |
Environmental Science |
description |
Figure 4. Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b). Abstract The abundant thaw lakes and ponds in the circumarctic receive a new pool of organic carbon as permafrost peat soils degrade, which can be exposed to significant irradiance that potentially increases as climate warms and ice cover shortens. Exposure to sunlight is known to accelerate the transformation of dissolved organic matter (DOM) into molecules that can be more readily used by microbes. We sampled the water from two common classes of ponds found in the ice-wedge system of continuous permafrost regions of Canada, polygonal and runnel ponds, and followed the transformation of DOM over 12 days by looking at dissolved organic carbon (DOC) concentration and DOM absorption and fluorescence properties. The results indicate a relatively fast decay of color (3.4 and 1.6% loss d −1 of absorption at 320 nm for the polygonal and runnel pond, respectively) and fluorescence (6.1 and 8.3% loss d −1 of total fluorescent components, respectively) at the pond surface, faster in the case of humic-like components, but insignificant losses of DOC over the observed period. This result indicates that direct DOM mineralization (photochemical production of CO 2 ) is apparently minor in thaw ponds compared to the photochemical transformation of DOM into less chromophoric and likely more labile molecules with a greater potential for microbial mineralization. Therefore, DOM photolysis in arctic thaw ponds can be considered as a catalytic mechanism, accelerating the microbial turnover of mobilized organic matter from thawing permafrost and the production of greenhouse gases, especially in the most shallow ponds. Under a warming climate, this mechanism will intensify as summers lengthen. |
format |
Still Image |
author |
Laurion, Isabelle Mladenov, Natalie |
author_facet |
Laurion, Isabelle Mladenov, Natalie |
author_sort |
Laurion, Isabelle |
title |
Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b) |
title_short |
Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b) |
title_full |
Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b) |
title_fullStr |
Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b) |
title_full_unstemmed |
Excitation–emission matrices (EEMs) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from PARAFAC (b) |
title_sort |
excitation–emission matrices (eems) of fluorescence of the two experimental ponds at the beginning ( t 0 ) and after 12 days ( t 12 ) of filtered incubation water under natural sunlight (a), and emission spectra (blue line) and excitation spectra (red line) of the four extracted components from parafac (b) |
publisher |
IOP Publishing |
publishDate |
2013 |
url |
https://dx.doi.org/10.6084/m9.figshare.1011775 https://iop.figshare.com/articles/figure/_Excitation_emission_matrices_EEMs_of_fluorescence_of_the_two_experimental_ponds_at_the_beginning_em/1011775 |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic Ice permafrost wedge* |
genre_facet |
Arctic Ice permafrost wedge* |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.6084/m9.figshare.1011775 |
_version_ |
1766348302497873920 |