New low-cost automated system of closed chambers to measure greenhouse gas emissions from the tundra

The northern high latitudes represent the world's largest soil carbon reservoir. Due to the rapid warming in the Arctic, permafrost thawing is expected to lead to increased emissions of greenhouse gases (GHG). Therefore, quantifying these emissions has become very important in order to determine the feedback impacts of GHG release from permafrost on the global climate. However, permafrost GHG emissions are difficult to quantify because direct measurements with conventional methods are generally expensive and time-consuming, resulting in short-spanned experiments and limited number of measurements. In order to take continuous measurements of GHG emissions over long periods of time, we developed and tested an affordable automated system of four closed chambers equipped with low-cost sensors and open-source microcontrollers. We measured carbon dioxide concentrations with a low-cost CO2 sensor and compared it with an infrared gas analyzer (IRGA). Compared to the IRGA, the sensor overestimated fluxes by only 6%, making it a good alternative to conventional devices to measure CO2 concentrations. The chambers were compared to a commercial chamber (SRC-1, PP Systems) and results showed a 15% discrepancy between the two types of chamber. However, more laboratory testing is necessary to confirm the exact cause of the discrepancy. This low-cost system shows high potential and represents a good alternative to existing methods and apparatuses to measure soil CO2 emissions. (C) 2016 Elsevier B.V. All rights reserved.