Estimating fluxes of CO2 and CH4 along the Siberian Yensei River

拟议中的工作将探索北极河流向大气释放的温室气体。这项研究的假设是，被冲入河流的陆基有机碳不会进入北冰洋，在那里它可能会沉积在沉积物中。相反，在到达北冰洋之前，微生物会分解这些有机碳，导致二氧化碳和甲烷这两种温室气体从河流流向大气。更令人担忧的是，随着本世纪北极泥炭地变暖和融化，在冻土中积累了数千年的有机物质将很容易被运输到河流中，经过加工，然后以二氧化碳和甲烷的形式释放到大气中。目前，这是一个未被充分探索的研究课题，部分原因是很难直接测量这些温室气体从河流到大气的转移。该项目的pi相信他们已经开发出了一种廉价合理的方法来估计这些通量的仪器。PI打算在俄罗斯的一个分水岭做这件事。由于游船费用将由俄罗斯合作者支付，因此pi要求提供少量的支持资金，用于开发仪器和旅行。这是一个相对较小的项目，只包括1个月的研究生参与。然而，与外国同事的合作被认为是非常积极的。此外，Amon在BI和外联方面有着良好的记录。在之前的工作中，阿蒙培训了几名研究生，并让一些本科生接触了北极研究。他在意大利TAMU国际研究中心组织了一个有国际参与的数据研讨会，包括几名研究生和本科生，并发起了？岛上的科学？在加尔维斯顿县每日新闻上发表了关于这些研究项目的短文。该计划没有理由相信这种积极推广和教育的承诺将会停止。西伯利亚大河流的流域在土壤和植被中储存了大量的有机碳。然而，碳从北极陆地向河流的横向输送、DOC的流内加工以及河网的温室气体逃逸尚未得到很好的确定。2015年夏季，Amon和同事在叶纳塞海域测量的溶解有机碳（DOC）表明，在淡水期，上游和下游的DOC差异很大，这表明1)DOC在运输过程中损失显著，2)植物和凋落物碳是输出到北冰洋的DOC的主要来源。拟议的项目将测量地表水和空气中CO2和CH4的浓度和同位素组成，与其他测量一起，将能够确定空气/水的气体交换。该合同将使PIs有机会参加2016年夏季在叶尼塞河2000公里长的河段上的游船活动。

The proposed work will explore the release of greenhouse gases from Arctic rivers to the atmosphere. The hypothesis of this work is that land-based organic carbon that gets flushed into rivers does not makes its way to the Arctic Ocean, where it could be deposited in the sediments. Rather, before reaching the Arctic Ocean, microbes decompose this organic carbon, resulting in a flux of CO2 and CH4, both greenhouse gases, from the rivers to the atmosphere. The larger concern is that as Arctic peatlands warm and thaw over this century, organic material that has built up over thousands of years in the frozen soils will become susceptible to transport to the rivers, processing, and then released to the atmosphere in the form of CO2 and CH4. Currently this is an under-explored research topic, partly because it is so difficult to directly measure the transfer of these greenhouse gases from the rivers to the atmosphere. The PIs of this project believe that they have developed the instrumentation to estimate these fluxes in a cheap and reasonable way. The PI intends to do this in a Russian watershed. As the cruise expenses will be paid by their Russian collaborators, the PIs are asking for a small amount of support funds to develop the instruments and for travel.This is a relatively small project and only includes for 1 month participation of a graduate student. However, the collaboration with foreign colleagues is viewed very positively. Moreover, Amon has a good track record with respect to BI and outreach. In previous work, Amon has trained several graduate students and exposed a number of undergraduate students to Arctic research. He has organized a data workshop with international participation including several graduate and undergraduate students at the TAMU international study center in Italy and initiated the ?science on the island? series to published short newspaper articles about these research projects in the Galveston County Daily News. The Program has no reason to believe that this commitment to active outreach and education will cease.The watersheds of the large Siberian rivers store significant amounts of organic carbon in soils and vegetation. However, the lateral transport of carbon from Arctic lands to the rivers, the in-stream processing of DOC, and the greenhouse gas evasion from the river networks has not been well determined. In the summer of 2015, dissolved organic carbon (DOC) measured in the Yenesei by Amon and colleagues indicates large differences in upstream and downstream DOC during the freshet period, suggesting 1) significant in-transit losses of DOC and 2) that plant and litter carbon is the predominant source of DOC exported to the Arctic Ocean. The proposed project will measure the concentration and isotopic composition of CO2 and CH4 in surface waters and air, which, together with other measurements, will permit the determination of air/water gas exchange. This award will allow the PIs to take advantage of an offer to participate in a cruise of opportunity on a 2000 km stretch of the Yenisei River in the summer 2016.