Enhanced nighttime gas emissions from a lake
| العنوان: | Enhanced nighttime gas emissions from a lake |
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| المؤلفون: | Podgrajsek, Eva, Sahlée, Erik, Rutgersson, Anna |
| المصدر: | IOP Conference Series: Earth and Environmental Science. |
| مصطلحات موضوعية: | Meteorology, Meteorologi |
| الوصف: | Methane (CH4) and carbon dioxide (CO2) are two important greenhouse gases. Previous studies have shown that lakes can be important natural sources of atmospheric CH4 and CO2. It is therefore important to monitor the fluxes of these gases between lakes and the atmosphere in order to understand the processes that govern the exchange. Most previous lake flux studies are based on chamber measurements, by using the eddy covariance method, the resolution in time and in space of the fluxes is increased, which gives more information on the governing processes. Eddy covariance measurements at a Swedish lake show that both methane fluxes (FCH4 ) and carbon dioxide fluxes (FCO2 ) experience high nighttime fluxes for a large part of the data set (largest median FCH4night ≈ 13 nmol m2 s-1 and smallest median FCH4day ≈ 4.0 nmol m-2 s-1, largest median FCO2night ≈ 0.2 μmol m2 s-1 and smallest median FCO2day ≈ 0.02 μmol m-2 s-1, with larger variability during night). For the diel cycle of the CH4 fluxes it is suggested that water side convection could enhance the transfer velocity, transport CH4 rich water to the surface, as well as trigger ebullition. The high nighttime CO2 fluxes could to a large extent be explained with enhanced transfer velocities due to water side convection. If gas fluxes are not measured during nighttime, when water side convection normally is generated, periods of potential high gas flux might be missed and estimations of the total amount of gas released from lakes to the atmosphere will be biased. |
| وصف الملف: | electronic |
| URL الوصول: | https://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-314492 https://doi.org/10.1088/1755-1315/35/1/012014 https://uu.diva-portal.org/smash/get/diva2:1070899/FULLTEXT01.pdf |
| قاعدة البيانات: | SwePub |
| DOI: | 10.1088/1755-1315/35/1/012014 |
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