Greenhouse Gas Emissions from Boreal Reservoirs in Manitoba and Qubec, Canada, Measured with Automated Systems

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• 作者：Maud Demarty ; Julie Bastien ; Alain Tremblay ; Raymond H. Hesslein ; Robert Gill
• 刊名：Environmental Science & Technology
• 出版年：2009
• 出版时间：December 1, 2009
• 年：2009
• 卷：43
• 期：23
• 页码：8908-8915
• 全文大小：267K
• 年卷期：v.43,no.23(December 1, 2009)
• ISSN：1520-5851

文摘

Growing concern over the contribution of freshwater reservoirs to increases in atmospheric greenhouse gas (GHG) concentrations and the relevance of long-term continuous measurements has led Fisheries and Oceans Canada, in conjunction with Manitoba Hydro, to develop continuous GHG monitors. Continuous water pCO₂, pCH₄, and pO₂ measurements were gathered to estimate gas fluxes in one temperate reservoir (Rivire-des-Prairies) and two boreal reservoirs (Eastmain-1 and Robert-Bourassa) in Qubec, and in four boreal reservoirs (Grand Rapids, Jenpeg, Kettle, and McArthur Falls) in Manitoba, Canada. Mean daily CO₂ fluxes ranged between 7 and 14 mmolCO₂·m⁻²·d⁻¹ in Manitoba and between 15 and 55 mmolCO₂·m⁻²·d⁻¹ in Qubec. Summertime episodes of water undersaturation in CO₂ were observed at Jenpeg, Kettle, and McArthur, suggesting higher productivities of these systems compared to the other systems studied. Mean daily CH₄ fluxes ranged between 0 and 69 μmolCH₄·m⁻²·d⁻¹ in Manitoba and between 9 and 48 μmolCH₄·m⁻²·d⁻¹ in Qubec. Comparisons of results obtained in the Eastmain-1 area using automated monitors, floating chambers or dissolved gas analyses over multiple-station field campaigns demonstrated that a continuous GHG monitor at a single sampling station provided representative and robust results.