Towards improved estimation of carbon balance in a low-Arctic mire: a micrometeorological eddy covariance approach to methane flux characterization.

气候正在变暖。世界上的北极地区已经被证明是以比地球上任何其他地区更快的速度变暖。这些北方高纬度地区在决定气候变化的全球影响方面可能发挥关键作用，因为它们覆盖了北方赫米斯特地区地球表面的很大一部分，并作为一个主要的碳汇，目前储存着地球上约11%的碳，被锁在北极苔原的有机土壤和泥炭中，以及代表这些北极地区的广泛沼泽系统中。因此，我们必须更好地了解目前决定地表和大气之间碳平衡和交换的因素，以便更好地预测北极持续变暖的可能后果。然而，这些高纬度地区的数据仍然稀少，不仅是在数据的空间覆盖方面，而且也许更重要的是在时间覆盖方面，跨越年周期较长时期的现有数据集仍然相对较少。就甲烷形式的碳而言，情况尤其如此。甲烷是一种强大的温室气体，自前工业时代以来，占全球辐射强迫增加的约20%。湿地在全球碳循环中扮演着重要的双重角色，既是最大的天然甲烷来源，也是一个巨大的净碳汇（也就是说，它从大气中锁定的二氧化碳比释放到大气中的更多）。全球约30%的湿地位于欧亚大陆北方，许多湿地分布在北极和亚北极地区。量化全球变暖的潜在影响以及任何积极的反馈，都需要通过空间和时间来代表景观的模型。这种模式必须以生态系统研究为基础，这些研究将提供必要的数据，以充分反映景观过程及其在空间和时间上的变化。目前的建议，连接生态系统科学家在达勒姆和斯特林有专门知识的测量甲烷同时在一系列的空间尺度，微气象学和建模的专门知识在爱丁堡，试图提供这样的关键数据有关的甲烷通量从北极沼泽在芬兰北部，以获得估计的碳汇和源在区域尺度的北方芬兰。我们建议使用所获得的理解和开发的模型，以更好地预测未来潜在的区域甲烷通量。我们将采取的方法是通过涡度协方差技术（一种无室技术，用于测量一部分景观中的甲烷，而不使用人工室方法，通过其使用，对被采样的植被/土壤产生影响）进行甲烷测量。该技术允许在集成的通量从各种植被和土壤组合，覆盖北极沼泽生态系统的异质表面。这里的关键优势是一个连续的记录CH 4通量之间的陆地表面和大气之间的一个较长的时期（约。在一年中的不同时间进行为期4周的活动，在这种情况下）。目前的建议的主要优势是：人员和设备的承诺，使甲烷通量测量没有不必要的，混淆的年际变化，在以前的一些研究中遇到的;和特别高的附加值，它提供，因为它直接建立在，并补充，正在进行的NERC资助的研究。

The climate is warming. The Arctic regions of the world have been shown to be warming at a rate faster than any other region on earth. These high northern latitude regions may play a critical role in determining the global impacts of climatic change because they cover a significant proportion of the earth's surface in the northern hermisphere and act as a major carbon sink, currently storing some 11% of the earth's carbon, locked away in the organic soils and peat of Arctic tundra and extensive mire sytems that are representative of these Arctic regions. Thus it is vital that we better understand the factors that currently determine the balance, and exchange of carbon between land surface and atmosphere so as to better predict the likely consequences of continued warming of the Arctic. However, these high latitude regions remain data sparse, not only in terms of spatial coverage of data, but perhaps as, or more, importantly, in terms of temporal coverage, with still relatively few data sets available spanning extended periods of the annual cycle. This is particularly the case in terms of carbon in the form of methane. Methane is a powerful greenhouse gas that accounts for about 20% of the increase in global radiative forcing since the pre-industrial era. Wetlands play an important dual role in the global carbon cycle, being both the largest natural methane source and a large net carbon sink (that is that it locks away more carbon dioxide from the atmosphere than it releases to it). About 30% of global wetlands are located in northern Eurasia; many throughout the Arctic and sub-Arctic regions. Quantifying the potential impacts of global warming, and any positive feedback, requires models that represent the landscape through both space and through time. Such models must be underpinned by ecosystem studies that will provide the data necessary to achieve adequate representation of landscape processes and how they vary through space and time. The present proposal, linking ecosystem scientists at Durham and Stirling having expertise in measurement of methane concurrently at a range of spatial scales, with micrometeorological and modelling expertise at Edinburgh, seeks to provide such key data related to methane flux from an Arctic mire in N Finland, so as to obtain estimates of carbon sinks and sources at the regional scale of northern Finland. We propose to use the understanding gained, and the models developed, to better predict potential future regional methane fluxes. The approach we will undertake is that of methane measurement by the eddy covariance technique (a chamberless technique for measuring methane across a portion of a landscape without using artificial chamber approaches which, by their very use, impact upon the vegetation/soils being sampled). The technique allows in integration of fluxes from the various vegetation and soil assemblages that characterise the heterogeneous surface of Arctic mire ecosystems. The key advantage here is a continous record of CH4 flux between land surface and atmosphere for an extended period (ca. 4 week campaigns at different times of the year, in this instance). Key strengths of the current proposal are: the commitment of personnel and equipment for extended periods to allow methane flux measurements to be made without the unwanted, confounding inter-annual variation that has been encountered in some previous studies; and the particularly high added value that it offers because it builds directly upon, and is complemented by, ongoing NERC-funded research.