Methane and other greenhouse gases in the Arctic - measurements, process studies and modelling (MAMM)

北极是大气中甲烷和其他温室气体的主要来源，包括自然排放和人为排放。北极温室气体源可能对全球产生重要影响，改变辐射强迫和大气氧化能力。此外，古记录和现在的研究都表明，某些来源，如湿地和甲烷水合物，可能表现出强烈的正反馈[Nisbet和Chappellaz， 2009]，因此变暖助长了变暖。迫切需要对北极温室气体源进行量化，包括强度、地理位置、特征（如湿地、天然气田、笼形物）和时间变化（夏季、冬季、白天、夜间），并评估其变化脆弱性。我们将通过测量和建模的综合方案来解决这些问题。将从地面和飞机对气体混合比（浓度）、同位素特征和源通量进行分析。过去和新的测量都将使用一套技术进行建模。通量将被应用到JULES陆地表面模型中。大气模拟，包括轨迹和逆模拟，将提高对局部/区域尺度的理解，确定北极排放在大尺度全球大气变化中的作用。

The Arctic is a major source of atmospheric methane and other greenhouse gases, with both natural and anthropogenic emissions. Arctic greenhouse gas sources have the potential to be important globally, changing radiative forcing and atmospheric oxidizing capacity. Moreover, both palaeorecords and present-day studies suggest some sources, such as wetlands and methane hydrates, may show strong positive feedbacks [Nisbet and Chappellaz, 2009], so that the warming feeds the warming. It is urgent that Arctic greenhouse gas sources should be quantified, by strength, geographic location, character (e.g. wetland, gasfield, clathrate), and by temporal variation (summer, winter, day, night), and their vulnerability to change assessed. We will address these issues by an integrated program of measurement and modelling. Analysis of gas mixing ratios (concentrations), isotopic character, and source fluxes, will be made both from the ground and aircraft. Both past and new measurements will be modelled using a suite of techniques. Fluxes will be implemented into the JULES land surface model. Atmospheric modelling, including trajectory and inverse modelling will improve understanding on the local/regional scale, placing the role of Arctic emissions in large scale global atmospheric change.