Tonya Delsontro

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Methane emission pathways and their importance were quantified during a yearlong survey of a temperate hydropower reservoir. Measurements using gas traps indicated very high ebullition rates, but due to the stochastic nature of ebullition a mass balance approach was crucial to deduce system-wide methane sources and losses. Methane diffusion from the(More)
Tropical reservoirs have been identified as important methane (CH(4)) sources to the atmosphere, primarily through turbine and downstream degassing. However, the importance of ebullition (gas bubbling) remains unclear. We hypothesized that ebullition is a disproportionately large CH(4) source from reservoirs with dendritic littoral zones because of(More)
Ebullition (bubbling) is an important mechanism for the transfer of methane (CH4) from shallow waters to the atmosphere. Because of their stochastic nature, however, ebullition fluxes are difficult to accurately resolve. Hydroacoustic surveys have the potential to significantly improve the spatiotemporal observation of emission fluxes, but knowledge of(More)
Inland waters transport and transform substantial amounts of carbon and account for ∼18% of global methane emissions. Large reservoirs with higher areal methane release rates than natural waters contribute significantly to freshwater emissions. However, there are millions of small dams worldwide that receive and trap high loads of organic carbon and can(More)
Heterogeneous benthic methane (CH4) dynamics from river deltas with important organic matter accumulation have been recently reported in various aquatic and marine environments. The spatial heterogeneity of dissolved CH4 concentrations and associated production and diffusion rates were investigated in the Rhone River Delta of Lake Geneva(More)
With its smaller size, well-known boundary conditions, and the availability of detailed bathymetric data, Lake Geneva’s subaquatic canyon in the Rhone Delta is an excellent analogue to understand sedimentary processes in deep-water submarine channels. A multidisciplinary research effort was undertaken to unravel the sediment dynamics in the active canyon.(More)
Lakes play an important role in the global carbon cycle, emitting significant amounts of the carbonic greenhouse gases, CO2 and methane (CH4). Nearly all lake studies have reported oxygenated surface waters oversaturated with (and thus continuously emitting) CH4, yet no consistent explanation exists to account for why CH4, which is produced in anoxic zones(More)
Methane (CH4) strongly contributes to observed global warming. As natural CH4 emissions mainly originate from wet ecosystems, it is important to unravel how climate change may affect these emissions. This is especially true for ebullition (bubble flux from sediments), a pathway that has long been underestimated but generally dominates emissions. Here we(More)
We monitored CH4 emissions during the ice-free period of an Alpine hydropower reservoir in the Swiss Alps, Lake Klöntal, to investigate mechanisms responsible for CH4 variability and to estimate overall emissions to the atmosphere. A floating eddy-covariance platform yielded total CH4 and CO2 emission rates at high temporal resolution, while hydroacoustic(More)