Methane dynamics in three different Siberian water bodies under winter and summer conditions
<p>Arctic regions and their water bodies are affected by a rapidly warming climate. Arctic lakes and small ponds are known to act as an important source of atmospheric methane.</p> <p>However, not much is known about other types of water bodies in permafrost regions, which incl...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-03-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/18/2047/2021/bg-18-2047-2021.pdf |
| _version_ | 1818863492848943104 |
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| author | I. Bussmann I. Fedorova B. Juhls P. P. Overduin M. Winkel M. Winkel |
| author_facet | I. Bussmann I. Fedorova B. Juhls P. P. Overduin M. Winkel M. Winkel |
| author_sort | I. Bussmann |
| collection | DOAJ |
| description | <p>Arctic regions and their water bodies are affected by a rapidly warming
climate. Arctic lakes and small ponds are known to act as an important
source of atmospheric methane.</p>
<p>However, not much is known about other types of water bodies in permafrost
regions, which include major rivers and coastal bays as a transition type
between freshwater and marine environments. We monitored dissolved methane
concentrations in three different water bodies (Lena River, Tiksi Bay, and
Lake Golzovoye, Siberia, Russia) over a period of 2 years. Sampling was
carried out under ice cover (April) and in open water (July–August). The
methane oxidation (MOX) rate and the fractional turnover rate (<span class="inline-formula"><i>k</i><sup>′</sup></span>)
in water and melted ice samples from the late winter of 2017 was determined with the radiotracer method.</p>
<p>In the Lena River winter methane concentrations were a quarter of the summer concentrations (8 nmol L<span class="inline-formula"><sup>−1</sup></span> vs. 31 nmol L<span class="inline-formula"><sup>−1</sup></span>), and mean winter MOX rate was low (0.023 nmol L<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span>). In contrast, Tiksi Bay winter methane concentrations were 10 times higher than in summer (103 nmol L<span class="inline-formula"><sup>−1</sup></span> vs. 13 nmol L<span class="inline-formula"><sup>−1</sup></span>). Winter MOX rates showed a median of 0.305 nmol L<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span>. In Lake Golzovoye, median methane concentrations in winter were 40 times higher than in summer (1957 nmol L<span class="inline-formula"><sup>−1</sup></span> vs. 49 nmol L<span class="inline-formula"><sup>−1</sup></span>). However, MOX was much
higher in the lake (2.95 nmol L<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span>) than in either the river or bay. The temperature had a strong influence on the MOX
(<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M14" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>Q</mi><mn mathvariant="normal">10</mn></msub><mo>=</mo><mn mathvariant="normal">2.72</mn><mo>±</mo><mn mathvariant="normal">0.69</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="86pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="6feb1c9dd7151ba58ac02a347754260d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-18-2047-2021-ie00001.svg" width="86pt" height="12pt" src="bg-18-2047-2021-ie00001.png"/></svg:svg></span></span>). In summer water temperatures ranged from 7–14 <span class="inline-formula"><sup>∘</sup></span>C and in winter from <span class="inline-formula">−0.7</span> to 1.3 <span class="inline-formula"><sup>∘</sup></span>C. In the ice cores a median methane concentration of 9 nM was observed, with no gradient between the ice surface and the bottom layer at the ice–water interface. MOX in the (melted) ice cores was mostly below the detection limit. Comparing methane concentrations in the ice with the underlaying water column revealed methane concentration in the water column 100–1000 times higher.</p>
<p>The winter situation seemed to favor a methane accumulation under ice,
especially in the lake with a stagnant water body. While on the other hand,
in the Lena River with its flowing water, no methane accumulation under ice
was observed. In a changing, warming Arctic, a shorter ice cover period is
predicted. With respect to our study this would imply a shortened time for
methane to accumulate below the ice and a shorter time for the less
efficient winter MOX. Especially for lakes, an extended time of ice-free
conditions could reduce the methane flux from the Arctic water bodies.</p> |
| first_indexed | 2024-12-19T10:16:38Z |
| format | Article |
| id | doaj.art-0071ddfe2c614fbb89b51f0a6f1b8714 |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-19T10:16:38Z |
| publishDate | 2021-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-0071ddfe2c614fbb89b51f0a6f1b87142022-12-21T20:26:12ZengCopernicus PublicationsBiogeosciences1726-41701726-41892021-03-01182047206110.5194/bg-18-2047-2021Methane dynamics in three different Siberian water bodies under winter and summer conditionsI. Bussmann0I. Fedorova1B. Juhls2P. P. Overduin3M. Winkel4M. Winkel5Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Helgoland, GermanyInstitute of Earth Sciences, St. Petersburg University, St. Petersburg, RussiaInstitute for Space Sciences, Department of Earth Sciences, Freie Universität Berlin, Berlin, GermanyAlfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Potsdam, GermanyGerman Research Centre for Geoscience, 3.7 Geomicrobiology Group, Potsdam, Germanycurrent address: German Research Centre for Geosciences, 3.5 Interface Geochemistry Group, Potsdam, Germany<p>Arctic regions and their water bodies are affected by a rapidly warming climate. Arctic lakes and small ponds are known to act as an important source of atmospheric methane.</p> <p>However, not much is known about other types of water bodies in permafrost regions, which include major rivers and coastal bays as a transition type between freshwater and marine environments. We monitored dissolved methane concentrations in three different water bodies (Lena River, Tiksi Bay, and Lake Golzovoye, Siberia, Russia) over a period of 2 years. Sampling was carried out under ice cover (April) and in open water (July–August). The methane oxidation (MOX) rate and the fractional turnover rate (<span class="inline-formula"><i>k</i><sup>′</sup></span>) in water and melted ice samples from the late winter of 2017 was determined with the radiotracer method.</p> <p>In the Lena River winter methane concentrations were a quarter of the summer concentrations (8 nmol L<span class="inline-formula"><sup>−1</sup></span> vs. 31 nmol L<span class="inline-formula"><sup>−1</sup></span>), and mean winter MOX rate was low (0.023 nmol L<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span>). In contrast, Tiksi Bay winter methane concentrations were 10 times higher than in summer (103 nmol L<span class="inline-formula"><sup>−1</sup></span> vs. 13 nmol L<span class="inline-formula"><sup>−1</sup></span>). Winter MOX rates showed a median of 0.305 nmol L<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span>. In Lake Golzovoye, median methane concentrations in winter were 40 times higher than in summer (1957 nmol L<span class="inline-formula"><sup>−1</sup></span> vs. 49 nmol L<span class="inline-formula"><sup>−1</sup></span>). However, MOX was much higher in the lake (2.95 nmol L<span class="inline-formula"><sup>−1</sup></span> d<span class="inline-formula"><sup>−1</sup></span>) than in either the river or bay. The temperature had a strong influence on the MOX (<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M14" display="inline" overflow="scroll" dspmath="mathml"><mrow><msub><mi>Q</mi><mn mathvariant="normal">10</mn></msub><mo>=</mo><mn mathvariant="normal">2.72</mn><mo>±</mo><mn mathvariant="normal">0.69</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="86pt" height="12pt" class="svg-formula" dspmath="mathimg" md5hash="6feb1c9dd7151ba58ac02a347754260d"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-18-2047-2021-ie00001.svg" width="86pt" height="12pt" src="bg-18-2047-2021-ie00001.png"/></svg:svg></span></span>). In summer water temperatures ranged from 7–14 <span class="inline-formula"><sup>∘</sup></span>C and in winter from <span class="inline-formula">−0.7</span> to 1.3 <span class="inline-formula"><sup>∘</sup></span>C. In the ice cores a median methane concentration of 9 nM was observed, with no gradient between the ice surface and the bottom layer at the ice–water interface. MOX in the (melted) ice cores was mostly below the detection limit. Comparing methane concentrations in the ice with the underlaying water column revealed methane concentration in the water column 100–1000 times higher.</p> <p>The winter situation seemed to favor a methane accumulation under ice, especially in the lake with a stagnant water body. While on the other hand, in the Lena River with its flowing water, no methane accumulation under ice was observed. In a changing, warming Arctic, a shorter ice cover period is predicted. With respect to our study this would imply a shortened time for methane to accumulate below the ice and a shorter time for the less efficient winter MOX. Especially for lakes, an extended time of ice-free conditions could reduce the methane flux from the Arctic water bodies.</p>https://bg.copernicus.org/articles/18/2047/2021/bg-18-2047-2021.pdf |
| spellingShingle | I. Bussmann I. Fedorova B. Juhls P. P. Overduin M. Winkel M. Winkel Methane dynamics in three different Siberian water bodies under winter and summer conditions Biogeosciences |
| title | Methane dynamics in three different Siberian water bodies under winter and summer conditions |
| title_full | Methane dynamics in three different Siberian water bodies under winter and summer conditions |
| title_fullStr | Methane dynamics in three different Siberian water bodies under winter and summer conditions |
| title_full_unstemmed | Methane dynamics in three different Siberian water bodies under winter and summer conditions |
| title_short | Methane dynamics in three different Siberian water bodies under winter and summer conditions |
| title_sort | methane dynamics in three different siberian water bodies under winter and summer conditions |
| url | https://bg.copernicus.org/articles/18/2047/2021/bg-18-2047-2021.pdf |
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