Methane and Dissolved Organic Matter in the Ground Ice Samples from Central Yamal: Implications to Biogeochemical Cycling and Greenhouse Gas Emission
Autor: | Elizaveta V. Shatrova, Marina Leibman, B. G. Vanshtein, Irina Streletskaya, P. B. Semenov, Alexander I. Kizyakov, Anfisa A. Pismeniuk, Sergei A. Malyshev |
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Jazyk: | angličtina |
Rok vydání: | 2020 |
Předmět: |
Biogeochemical cycle
010504 meteorology & atmospheric sciences 010502 geochemistry & geophysics Permafrost 01 natural sciences Methane Ice wedge chemistry.chemical_compound greenhouse gas emission Dissolved organic carbon ground ice Organic matter Nitrogen cycle 0105 earth and related environmental sciences chemistry.chemical_classification lcsh:QE1-996.5 dissolved organic matter lcsh:Geology climate change chemistry Greenhouse gas Environmental chemistry General Earth and Planetary Sciences Environmental science permafrost biogeochemical cycling |
Zdroj: | Geosciences, Vol 10, Iss 450, p 450 (2020) Geosciences Volume 10 Issue 11 |
ISSN: | 2076-3263 |
Popis: | Permafrost thawing leads to mobilization of the vast carbon pool into modern biogeochemical cycling through the enhanced release of dissolved organic matter (DOM) and production of greenhouse gases (CO2 and CH4). In this work, we focus on the study of methane and DOM distribution and genesis in the ground ice samples of thermodenudational exposure in the Central Yamal (Russian Arctic). We propose that the liberation of the ice-trapped CH4 and generation of CO2 by DOM mineralization are the earliest factors of atmospheric greenhouse gases emission as a result of permafrost thawing. The observed enormously &ldquo light &rdquo isotope signatures of methane (&delta 13C < &minus 80&permil &delta D < 390&permil ) found in the tabular ground ice units significantly divergent in morphology and localization within the exposuremay be related to subzero (cryogenic) carbonate reduction a as significant factor of the local methane enrichment. DOM is mainly formed (> 88%) by biochemically refractory humic acids. Distribution of the labile protein-like DOM reflects the specific features of carbon and nitrogen cycles in the tabular ground ice and ice wedge samples. Tabular ground ice units are shown to be a significant source of methane and high quality organic matter as well as dissolved inorganic nitrogen (DIN). Ice wedges express a high variation in DOM composition and lability. |
Databáze: | OpenAIRE |
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