Dissolved organic matter photolysis in Canadian arctic thaw ponds.
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 transformati...
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ftinrsquebec:oai:espace.inrs.ca:3463 2023-05-15T14:26:08+02:00 Dissolved organic matter photolysis in Canadian arctic thaw ponds. Laurion, Isabelle Mladenov, Natalie 2013 application/pdf https://espace.inrs.ca/id/eprint/3463/ https://espace.inrs.ca/id/eprint/3463/1/P2406.pdf https://doi.org/10.1088/1748-9326/8/3/035026 en eng https://espace.inrs.ca/id/eprint/3463/1/P2406.pdf Laurion, Isabelle et Mladenov, Natalie (2013). Dissolved organic matter photolysis in Canadian arctic thaw ponds. Environmental Research Letters , vol. 8 , nº 3. Article number 035026. DOI:10.1088/1748-9326/8/3/035026 <https://doi.org/10.1088/1748-9326%2F8%2F3%2F035026>. doi:10.1088/1748-9326/8/3/035026 DOM photobleaching thermokarst lakes permafrost Article Évalué par les pairs 2013 ftinrsquebec https://doi.org/10.1088/1748-9326/8/3/035026 2023-02-10T11:42:27Z 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 CO2) 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. Article in Journal/Newspaper Arctic Arctic Ice permafrost Thermokarst wedge* Institut national de la recherche scientifique, Québec: Espace INRS Arctic Canada Environmental Research Letters 8 3 035026 |
institution |
Open Polar |
collection |
Institut national de la recherche scientifique, Québec: Espace INRS |
op_collection_id |
ftinrsquebec |
language |
English |
topic |
DOM photobleaching thermokarst lakes permafrost |
spellingShingle |
DOM photobleaching thermokarst lakes permafrost Laurion, Isabelle Mladenov, Natalie Dissolved organic matter photolysis in Canadian arctic thaw ponds. |
topic_facet |
DOM photobleaching thermokarst lakes permafrost |
description |
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 CO2) 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 |
Article in Journal/Newspaper |
author |
Laurion, Isabelle Mladenov, Natalie |
author_facet |
Laurion, Isabelle Mladenov, Natalie |
author_sort |
Laurion, Isabelle |
title |
Dissolved organic matter photolysis in Canadian arctic thaw ponds. |
title_short |
Dissolved organic matter photolysis in Canadian arctic thaw ponds. |
title_full |
Dissolved organic matter photolysis in Canadian arctic thaw ponds. |
title_fullStr |
Dissolved organic matter photolysis in Canadian arctic thaw ponds. |
title_full_unstemmed |
Dissolved organic matter photolysis in Canadian arctic thaw ponds. |
title_sort |
dissolved organic matter photolysis in canadian arctic thaw ponds. |
publishDate |
2013 |
url |
https://espace.inrs.ca/id/eprint/3463/ https://espace.inrs.ca/id/eprint/3463/1/P2406.pdf https://doi.org/10.1088/1748-9326/8/3/035026 |
geographic |
Arctic Canada |
geographic_facet |
Arctic Canada |
genre |
Arctic Arctic Ice permafrost Thermokarst wedge* |
genre_facet |
Arctic Arctic Ice permafrost Thermokarst wedge* |
op_relation |
https://espace.inrs.ca/id/eprint/3463/1/P2406.pdf Laurion, Isabelle et Mladenov, Natalie (2013). Dissolved organic matter photolysis in Canadian arctic thaw ponds. Environmental Research Letters , vol. 8 , nº 3. Article number 035026. DOI:10.1088/1748-9326/8/3/035026 <https://doi.org/10.1088/1748-9326%2F8%2F3%2F035026>. doi:10.1088/1748-9326/8/3/035026 |
op_doi |
https://doi.org/10.1088/1748-9326/8/3/035026 |
container_title |
Environmental Research Letters |
container_volume |
8 |
container_issue |
3 |
container_start_page |
035026 |
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1766298611827605504 |