Laser-based analyzer for detection of 12C/13C and H/D in methane

除了二氧化碳之外，甲烷是当前气候变化背景下的重要温室气体。大气中的甲烷浓度目前正在上升;然而，天然和人为甲烷来源及其驱动因素迄今尚未完全解决。将在明斯特大学景观生态学研究所中心实验室建立一个双激光甲烷分析仪，用于分析甲烷中碳-13和氘的丰度，以研究沉积物、土壤、沿海和淡水湿地中的甲烷循环和通量。使用碳和氢的稳定同位素将使我们能够解开不同的产甲烷途径，并在这些高度相关的生态系统中追踪甲烷氧化。我们的目标是：i）了解不同氧化还原条件下甲烷循环的控制，ii）研究其与固氮的联系，iii）研究湿地恢复的影响，iv）解决湿地根际植物-微生物的相互作用，v）研究解冻永冻土景观中的甲烷循环，和vi）研究高地土壤氧化吸收甲烷。因此，所要求的系统将用于环境浓度（2-10 ppm）的大气样品，以及培养物中的气体样品或土壤和沉积物中甲烷浓度高达2.5%（体积）的原位样品。为此，该系统将配备自动进样系统，以将样品浓度调整至仪器的测量范围。或者，该仪器将能够通过在非常短的响应时间内以流通模式分析气体来实时跟踪变化，以便与自动气体通量室系统或实验室中具有恒定通量测量的中生态系统装置一起沿着使用。此外，一个防风雨，温度控制外壳将允许现场操作的仪器和其直接连接到现有的气体通量室系统现场。该仪器的真空泵系统将具有在电源故障的情况下保护激光光学器件的安全特征，并且具有在现场次优电源下操作的低功耗。该系统将主要由生态水文学和生物地球化学小组与生物圈生物地球化学小组和土壤生态学和土地利用小组合作运行，但一般向研究所中心实验室内外的所有用户开放。使用基于网络的系统来安排测量时间。由于产生的数据量有限，数据可以存储在机构服务器上，并定期备份，可以在公共或大学拥有的开放获取平台上与出版物、代码或研究简编一起公开沿着。

Methane aside of carbon dioxide is the important greenhouse gas in the context of current climatic change. Methane concentrations in the atmosphere are currently rising; however, the natural and anthropogenic methane sources and their drivers have so far not been fully resolved. A dual laser methane analyser for the abundance of carbon-13 and deuterium in methane is to be established at the central laboratory of the Institute of Landscape Ecology, University of Münster, to address the methane cycle and fluxes in sediments, soils, coastal, and freshwater wetlands. The use of both stable isotopes of carbon and hydrogen will enable us to disentangle different methanogenic pathways and trace methane oxidation in these highly relevant ecosystems. We aim i) to understand controls of the methane cycle under varying redox conditions, ii) to study its link to nitrogen fixation, iii) to study effects of wetland restoration iv) to address plant-microbe interactions in the wetland rhizospheres, v) to study methane cycling in thawing permafrost landscapes, and vi) to study methane uptake by oxidation in upland soils. The requested system is thus to be used for atmospheric samples of ambient concentrations (2-10 ppm) and for gas samples from incubations or in-situ samples from soils and sediments at elevated concentrations up to 2.5 % methane by volume. To this end, the system will be equipped with an automated inlet system to adjust the concentrations of samples to the measurement range of the instrument. Alternatively, the instrument will be capable of tracking changes in real-time by analyzing gas in a flow through mode at very short response times in order to be used along with automated gas flux chamber systems or mesocosm setups with constant flux measurements in the laboratory. Moreover, a weather-proof, temperature-controlled enclosure will allow field operation of the instrument and its direct connection to existing gas flux chamber systems on-site. The vacuum pumping system of the instrument will have safety features to protect the laser-optics in case of power failures and have a low power consumption for operation under suboptimal power supply in the field. The system will be mainly operated by the Ecohydrology and Biogeochemistry group, in cooperation with the Rhizosphere Biogeochemistry group and the Soil Ecology and Land Use group, but generally be open to all users in the central laboratory of the institute and beyond. Access is organized using a web-based system to schedule measurement times. As only limited amounts of data are generated, data can be stored on institutional servers with regular backups and can be made publicly available along with publications, codes or research compendia on common or on university-owned open-access platforms.