Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.5194/acp-19-4041-2019 |
Characterisation of short-term extreme methane fluxes related to non-turbulent mixing above an Arctic permafrost ecosystem | |
Schaller, Carsten1,2,4; Kittler, Fanny2; Foken, Thomas1,3; Goeckede, Mathias2 | |
2019-04-01 | |
发表期刊 | ATMOSPHERIC CHEMISTRY AND PHYSICS |
ISSN | 1680-7316 |
EISSN | 1680-7324 |
出版年 | 2019 |
卷号 | 19期号:6页码:4041-4059 |
文章类型 | Article |
语种 | 英语 |
国家 | Germany |
英文摘要 | Methane (CH4) emissions from biogenic sources, such as Arctic permafrost wetlands, are associated with large uncertainties because of the high variability of fluxes in both space and time. This variability poses a challenge to monitoring CH4 fluxes with the eddy covariance (EC) technique, because this approach requires stationary signals from spatially homogeneous sources. Episodic outbursts of CH4 emissions, i.e. triggered by spontaneous outgassing of bubbles or venting of methane-rich air from lower levels due to shifts in atmospheric conditions, are particularly challenging to quantify. Such events typically last for only a few minutes, which is much shorter than the common averaging interval for EC (30 min) The steady-state assumption is jeopardised, which potentially leads to a non-negligible bias in the CH4 flux. Based on data from Chersky, NE Siberia, we tested and evaluated a flux calculation method based on wavelet analysis, which, in contrast to regular EC data processing, does not require steady-state conditions and is allowed to obtain fluxes over averaging periods as short as 1 min Statistics on meteorological conditions before, during, and after the detected events revealed that it is atmospheric mixing that triggered such events rather than CH4 emission from the soil. By investigating individual events in more detail, we identified a potential influence of various mesoscale processes like gravity waves, low-level jets, weather fronts passing the site, and cold-air advection from a nearby mountain ridge as the dominating processes. The occurrence of extreme CH4 flux events over the summer season followed a seasonal course with a maximum in early August, which is strongly correlated with the maximum soil temperature. Overall, our findings demonstrate that wavelet analysis is a powerful method for resolving highly variable flux events on the order of minutes, and can therefore support the evaluation of EC flux data quality under non-steady-state conditions. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000463008900001 |
WOS关键词 | COHERENT MOTIONS ; CARBON-DIOXIDE ; BOUNDARY-LAYER ; CH4 EMISSIONS ; FOREST CANOPY ; FOSSIL-FUEL ; CO2 FLUX ; COVARIANCE ; EXCHANGE ; TUNDRA |
WOS类目 | Environmental Sciences ; Meteorology & Atmospheric Sciences |
WOS研究方向 | Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/181870 |
专题 | 地球科学 |
作者单位 | 1.Univ Bayreuth, Dept Micrometeorol, D-95440 Bayreuth, Germany; 2.Max Planck Inst Biogeochem, D-07745 Jena, Germany; 3.Univ Bayreuth, Bayreuth Ctr Ecol & Environm Res BayCEER, D-95440 Bayreuth, Germany; 4.Univ Munster, Inst Landscape Ecol, Climatol Res Grp, Heisenbergstr 2, D-48149 Munster, Germany |
推荐引用方式 GB/T 7714 | Schaller, Carsten,Kittler, Fanny,Foken, Thomas,et al. Characterisation of short-term extreme methane fluxes related to non-turbulent mixing above an Arctic permafrost ecosystem[J]. ATMOSPHERIC CHEMISTRY AND PHYSICS,2019,19(6):4041-4059. |
APA | Schaller, Carsten,Kittler, Fanny,Foken, Thomas,&Goeckede, Mathias.(2019).Characterisation of short-term extreme methane fluxes related to non-turbulent mixing above an Arctic permafrost ecosystem.ATMOSPHERIC CHEMISTRY AND PHYSICS,19(6),4041-4059. |
MLA | Schaller, Carsten,et al."Characterisation of short-term extreme methane fluxes related to non-turbulent mixing above an Arctic permafrost ecosystem".ATMOSPHERIC CHEMISTRY AND PHYSICS 19.6(2019):4041-4059. |
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