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d(13)C-CH4 reveals CH4 variations over oceans from mid-latitudes to the Arctic.

https://arctichealth.org/en/permalink/ahliterature265870
Source
Sci Rep. 2015;5:13760
Publication Type
Article
Date
2015
Author
Juan Yu
Zhouqing Xie
Liguang Sun
Hui Kang
Pengzhen He
Guangxi Xing
Source
Sci Rep. 2015;5:13760
Date
2015
Language
English
Publication Type
Article
Abstract
The biogeochemical cycles of CH4 over oceans are poorly understood, especially over the Arctic Ocean. Here we report atmospheric CH4 levels together with d(13)C-CH4 from offshore China (31°N) to the central Arctic Ocean (up to 87°N) from July to September 2012. CH4 concentrations and d(13)C-CH4 displayed temporal and spatial variation ranging from 1.65 to 2.63 ppm, and from -50.34% to -44.94% (mean value: -48.55?±?0.84%), respectively. Changes in CH4 with latitude were linked to the decreasing input of enriched d(13)C and chemical oxidation by both OH and Cl radicals as indicated by variation of d(13)C. There were complex mixing sources outside and inside the Arctic Ocean. A keeling plot showed the dominant influence by hydrate gas in the Nordic Sea region, while the long range transport of wetland emissions were one of potentially important sources in the central Arctic Ocean. Experiments comparing sunlight and darkness indicate that microbes may also play an important role in regional variations.
PubMed ID
26323236 View in PubMed
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Methyl iodine over oceans from the Arctic Ocean to the maritime Antarctic.

https://arctichealth.org/en/permalink/ahliterature272839
Source
Sci Rep. 2016;6:26007
Publication Type
Article
Date
2016
Author
Qihou Hu
Zhouqing Xie
Xinming Wang
Juan Yu
Yanli Zhang
Source
Sci Rep. 2016;6:26007
Date
2016
Language
English
Publication Type
Article
Abstract
Studies about methyl iodide (CH3I), an important atmospheric iodine species over oceans, had been conducted in some maritime regions, but the understanding of the spatial distribution of CH3I on a global scale is still limited. In this study, we reports atmospheric CH3I over oceans during the Chinese Arctic and Antarctic Research Expeditions. CH3I varied considerably with the range of 0.17 to 2.9 pptv with absent of ship emission. The concentration of CH3I generally decreased with increasing latitudes, except for higher levels in the middle latitudes of the Northern Hemisphere than in the low latitudes. For sea areas, the Norwegian Sea had the highest CH3I concentrations with a median of 0.91 pptv, while the Central Arctic Ocean had the lowest concentrations with all values below 0.5 pptv. CH3I concentration over oceans was affected by many parameters, including sea surface temperature, salinity, dissolved organic carbon, biogenic emissions and input from continents, with distinctive dominant factor in different regions, indicating complex biogeochemical processes of CH3I on a global scale.
PubMed ID
27184471 View in PubMed
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