Dissolved Methane and Carbon Dioxide Fluxes in Subarctic and Arctic Regions: Assessing Measurement Techniques and Spatial Gradients

Mean annual temperatures are rising globally with larger increases in the Arctic and subarctic. Along with changes in temperature, a strong response by Arctic ecosystems is expected. The fate of the carbon stored in these ecosystems can potentially modulate the global carbon cycle and the atmospheric greenhouse gas budgets of methane (CH₄) and carbon dioxide (CO₂). As the need to understand and model these complex systems rises, it is essential to determine the degree of spatial heterogeneity of water-to-air fluxes of CO₂ and CH₄ and how these distributions influence regional to global scale extrapolations. Here we use a portable method to obtain high spatial resolution measurements of concentrations and diffusive water-to-air fluxes of methane (CH₄) and carbon dioxide (CO₂) from two subarctic coastal regions (Kasitsna and Jakolof Bays) and an Arctic lake (Toolik Lake). The goals of this study are to determine distributions of these concentrations and fluxes to (1) critically evaluate the established protocols of collecting discrete water samples for these determinations and (2) provide a first-order extrapolation of the regional impacts of these diffusive atmospheric fluxes.