Dissolved and Particulate Organic Carbon Characteristics in Summer and Winter Waters of the Lena Delta
Ogneva, O.; Mollenhauer, G.; Sanders, T.; Juhls, B.; Palmtag, J.; Fuchs, M.; Hammes, J.; Grotheer, H.; Mann, P.J.; Opfergelt, S.; Strauss, J. (2026). Dissolved and Particulate Organic Carbon Characteristics in Summer and Winter Waters of the Lena Delta. Permafrost and Periglacial Processes 37(1): 154-166. https://dx.doi.org/10.1002/ppp.70021
In: Permafrost and Periglacial Processes. Wiley: Hoboken. ISSN 1045-6740; e-ISSN 1099-1530, more
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| Author keywords |
laptev sea;eroding permafrost;arctic-ocean;river delta;ne siberia;matter;cycle;geochemistry;degradation;hydrology |
| Authors | | Top |
- Ogneva, O.
- Mollenhauer, G.
- Sanders, T.
- Juhls, B.
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- Palmtag, J.
- Fuchs, M.
- Hammes, J.
- Grotheer, H.
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- Mann, P.J.
- Opfergelt, S., more
- Strauss, J.
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| Abstract |
Rapid Arctic warming accelerates permafrost thaw, altering water flow and organic matter transport to aquatic ecosystems. To identify sources and seasonality of OC at the mouth of the Lena River, we measured summer and winter concentrations and C isotopes (triangle 14C and delta 13C) of DOC and POC along a 140-km transect of the Lena Delta. Despite low water flow during winter, DOC concentrations in the Lena Delta were higher than those measured at the end of the summer (6.31 +/- 0.60 and 5.54 +/- 0.17 mg L-1, respectively). We found pronounced differences in the DOC isotopic composition of waters between seasons (winter: mean = -16 parts per thousand +/- 16 parts per thousand ranging between -14 parts per thousand and 46 parts per thousand and summer: mean = 41 parts per thousand +/- 26 parts per thousand in the range between -47 parts per thousand and 79 parts per thousand). triangle 14C of winter DOC suggested higher relative contributions of older carbon compared to summer DOC, which is enriched in 14C. POC in winter was lower (0.13 +/- 0.06 and 0.40 +/- 0.10 mgC L-1, respectively) and enriched in delta 13C (-29.7 +/- 2.2 and -32.4 parts per thousand +/- 0.8 parts per thousand, respectively) compared to summer, while no difference was found for triangle 14C. This study with its unique dataset on the largest Arctic delta will help to assess the ongoing changes with climate warming at this frontier between the land and the ocean realm. Explicitly, the inclusion of winter sampling and isotopic analysis makes this study very valuable for assessing the biogeochemical response of the Arctic's biggest delta, as well as beyond. |
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