Novel probes for real time monitoring of dissolved gases and their isotopologues in aquatic ecosystems

Ocean ecosystems are critical to the regulation of Earth’s climate and biodiversity, while also hosting a range of direct and indirect benefits to people, from food supply to recreation. Coastal ocean systems are dynamic regions especially rich in diverse biological and geochemical interactions. However, major gaps exist in our knowledge of the primary biogeochemical processes and the factors regulating their relative importance. Nitrous oxide (N2O) and methane (CH4), produced and cycled within coastal and ocean environments, are important greenhouse gases with major roles in climate change. Our understanding of the distribution and dynamics of the underlying processes controlling their fluxes is limited by a lack of high-resolution spatial-temporal measurements. The overall objective of the project is to design a field deployable, real-time, in situ system to quantify dissolved greenhouse gases (N2O and CH4 and their isotopologues) in ocean ecosystems. In Phase I we will develop permeable, hydrophobic probes to extract dissolved gases without intrusion of liquid water; configure a collection protocol for efficient transfer of the gases; interface probes and extraction and sampling system with high-sensitivity infrared spectrometry; demonstrate the overall system with ocean seawater; and outline the Phase II system and field demonstration.