Numerous recent studies have documented the significant role that inland freshwaters such as lakes and rivers have on the global carbon cycle of the atmosphere. However, many of these studies lack continuous, spatially distributed observations of carbon dioxide efflux, instead relying on extrapolation from a limited set for each water body. One source of these observations is manually deployed, floating chamber measurements, which are labor-intensive and subject to sampling limitations of humans and boats.
Spafford and Risk  introduce a new approach, relying on recently developed low-cost “forced diffusion” sensors deployed as novel continuous, automatic flux chambers. They focus on the part of lakes known to be highly dynamic – the littoral zone where the shoreline transitions from wetland to lake – and took hourly samples at three locations over six months. The sensors depict larger magnitudes and enhanced diel variations in carbon dioxide fluxes closer to the shoreline, with both sources and sinks occurring throughout the open water season of an oligotrophic lake in Nova Scotia, Canada. The results open new questions on optimal spatial sampling of lake gas exchange, and the importance of sampling variations across all hours of the day, in shoulder seasons, and across major environmental gradients.
Citation: Spafford, L., & Risk, D. . Spatiotemporal variability in lake‐atmosphere net CO2 exchange in the littoral zone of an oligotrophic lake. Journal of Geophysical Research: Biogeosciences, 123. https://doi.org/10.1002/2017JG004115
—Ankur Rashmikant Desai, Editor, JGR: Biogeosciences