Methane and total hydrocarbon analyzer to sample emission from peatlands

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Climate change and atmospheric composition are tightly linked through the radiative and thermal properties of atmospheric gases.  Much focus has been on the 'big' three greenhouse gases (GHGs) - CO2, CH4, and N2O and overriding importance of water vapour.  However, it is recognized by the Intergovernmental Panel on Climate Change  that there are other trace gases that could be of importance but the uncertainty in their emissions to the atmosphere is too large to assess their role with any level of confidence.  One class of trace gases in this group are the volatile organic compounds (VOCs).  VOCs have both anthropogenic and biogenic origins.  They are emitted from terrestrial ecosystems, mostly as non-methane hydrocarbons (NMHC).  They are important because their photochemical oxidation results in the production ozone which is a strong GHG while at the same time they are also aerosols - hence they are involved in both positive and negative climate feedbacks.  Almost all measurements of VOCs have been done in tropical ecosystems, but since evergreen shrubs and mosses, known emitters of VOCs, cover most northern peatlands they could be a significant source of VOCs.  Peatlands are known as huge stores of carbon, but no study has characterized their emission of VOCs.  Our objective is to add to an automated chamber system we have operated for the last two years on a northern peatland two new analytical instruments that will allow us to measure continuously NMHC.  With these measurements we will examine the relationship between the emissions and the environmental and ecological controls on VOC flux.  This research will provide an important addition to the knowledge of VOC emissions from terrestrial ecosystems and we help us delineate their possible role in a negative feedback loop in the climate system.  If the source proves to be significant then we will use the results of this study to incorporate VOCs production and emissions into our peatland biogeochemistry models.