Methane loss from Arctic: towards an annual budget of CH4 emissions from tundra ecosystems across a latitudinal gradient

该研究项目将调查阿拉斯加北极地区三个地点（巴罗、阿夸苏克和伊沃图克）全年的甲烷和二氧化碳通量，这些地点横跨从北极海岸平原北部到阿拉斯加布鲁克斯山脉山麓约300公里的纬度梯度。这些测量将用于改进对年度温室气体通量的速率、模式和控制的估计，特别有助于了解秋季、冬季和春季的通量。该项目将是对横跨阿拉斯加北极样带的三个冻土带生态系统的甲烷和二氧化碳净排放量进行全面年度预算估算的首批努力之一。最重要的是非夏季CH4排放的量化，因为它对总体气候效应有潜在的巨大影响。由于恶劣的天气和远程监测站，这些信息在历史上很难收集。测量技术的最新进展将使这些研究在偏远地区和极端天气条件下可行。特别是，本研究将在最偏远的地点（Ivotuk）使用新的封闭路径LI-7200和自清洁和加热，低功耗，开放路径LI-7700 CH4分析仪。该团队将使用封闭路径的洛斯加托斯CH4分析仪来校正巴罗和阿特卡苏克遗址的水的交叉敏感性。一个加热的声波A级METEK将用于记录湍流测量。原位测量氧化还原电位、pH值、溶解气体、土壤和土壤孔隙水的化学特性以及宏基因组分析将阐明主要的呼吸途径。项目科学家和SDSU将与Reuben H. Fleet科学中心合作，以提高对极地和气候变化的认识和理解。项目活动将包括气候变化讲习班和研讨会，以及针对圣地亚哥地区的教师和公众以及巴罗社区的潜在温室气体反馈。

The research project will investigate year-around CH4 and CO2 fluxes at three Alaskan Arctic sites (Barrow, Aquasuk, and Ivotuk) across a latitudinal gradient of about 300 Km from the northern part of the Arctic Coastal Plain to the foothills of the Brooks Range, in Alaska. These measurements will be used to improve estimates of rates and patterns of and controls on annual GHG fluxes, with special contribution to understanding of the fall, winter and spring fluxes. This project will be among the first efforts toward the estimation of a full annual budget of both CH4 and CO2 net emissions from three tundra ecosystems across a transect in Arctic Alaska. Of primary importance is the quantification of non-summertime CH4 emissions because of the potentially large impact on overall climatic effects. This information has historically been very difficult to collect because of severe weather and remote monitoring stations. Recent advances in measurement technology will make these studies feasible in remote locations and under extreme weather conditions. In particular, this research will make use of the new closed-path LI-7200 and the self-cleaning and heated, low-power,open-path LI-7700 CH4 analyzer for the most remote site (Ivotuk). The team will employ the closed-path CH4 Los Gatos analyzer that corrects for the cross-sensitivity of water for the Barrow and Atqasuk sites. A heated sonic Class-A METEK will be used to record turbulence measurements. In-situ measurements of oxidation-reduction potential, pH, dissolved gases, chemical characterization of soils and soil pore water, and metagenomic analysis will elucidate the dominant respiratory pathways. Project scientists and SDSU will partner with the Reuben H. Fleet Science Centre to improve polar and climate change knowledge and understanding. Project activities will include workshops and seminars on climate change, and potential GHG feedbacks in the Arctic for teachers and the general public in the San Diego area, and for the community in Barrow.