Estimating fluxes of CO2 and CH4 along the Siberian Yensei River

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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.