Disentangling methane and carbon dioxide sources and transport across the Russian Arctic from aircraft measurements
<p>A more accurate characterization of the sources and sinks of methane (CH<span class="inline-formula"><sub>4</sub></span>) and carbon dioxide (CO<span class="inline-formula"><sub>2</sub></span>) in the vulnerable Arctic envi...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/2293/2023/acp-23-2293-2023.pdf |
| Summary: | <p>A more accurate characterization of the sources and sinks of
methane (CH<span class="inline-formula"><sub>4</sub></span>) and carbon dioxide (CO<span class="inline-formula"><sub>2</sub></span>) in the vulnerable Arctic
environment is required to better predict climate change. A large-scale
aircraft campaign took place in September 2020 focusing on the Siberian
Arctic coast. CH<span class="inline-formula"><sub>4</sub></span> and CO<span class="inline-formula"><sub>2</sub></span> were measured in situ during the
campaign and form the core of this study. Measured ozone (O<span class="inline-formula"><sub>3</sub></span>) and
carbon monoxide (CO) are used here as tracers. Median CH<span class="inline-formula"><sub>4</sub></span> mixing ratios
are fairly higher than the monthly mean hemispheric reference (Mauna Loa,
Hawaii, US) with 1890–1969 ppb vs. 1887 ppb respectively, while CO<span class="inline-formula"><sub>2</sub></span>
mixing ratios from all flights are lower (408.09–411.50 ppm vs. 411.52 ppm).
We also report on three case studies. Our analysis suggests that during the
campaign the European part of Russia's Arctic and western Siberia were
subject to long-range transport of polluted air masses, while the east was
mainly under the influence of local emissions of greenhouse gases. The
relative contributions of the main anthropogenic and natural sources of
CH<span class="inline-formula"><sub>4</sub></span> are simulated using the Lagrangian model FLEXPART in order to
identify dominant sources in the boundary layer and in the free troposphere.
On western terrestrial flights, air mass composition is influenced by
emissions from wetlands and anthropogenic activities (waste management,
fossil fuel industry, and to a lesser extent the agricultural sector), while
in the east, emissions are dominated by freshwater, wetlands, and the
oceans, with a likely contribution from anthropogenic sources related to
fossil fuels. Our results highlight the importance of the contributions from
freshwater and ocean emissions. Considering the large uncertainties
associated with them, our study suggests that the emissions from these aquatic
sources should receive more attention in Siberia.</p> |
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| ISSN: | 1680-7316 1680-7324 |