Methane and nitrous oxide
The marine environment is a net source of two important greenhouse gases, methane and nitrous oxide. The temporal and spatial distributions of methane and nitrous oxide are controlled by the interaction of complex microbial, geochemical and physical processes. A series of capacity-building efforts to standardize and improve measurements of methane and nitrous oxide has been initiated. The activities include the distribution of standards (Bullister et al., 2017), intercomparison exercises (Wilson et al., 2018), workshops (Wilson et al., 2020), and a forthcoming best practice guide. There are also plans to produce and distribute consensus material in the near future. These capacity-building efforts lay the foundations for a coordinated observing program for methane and nitrous oxide in the marine environment.
Participants at a workshop held at Lake Arrowhead, California in October 2018 to discuss the priorities for oceanic methane and nitrous oxide research. The workshop proceedings were published in Wilson et al. (2020)
A brief narrative of methane and nitrous oxide in the ocean along with scientific priorities for future research. The video was produced by Thom Hoffman in October 2018, as part of an OCB-sponsored workshop.
The temporal and spatial distributions of methane and nitrous oxide are measured as part of targeted expeditions, repeat hydrographic surveys, and time-series monitoring programs. The monitoring stations that conduct long-term time-series measurements of methane and nitrous oxide span a range of biogeochemical provinces and provide the seasonal and interannual contextual background that allow long-term temporal trends and episodic events to be identified. The monitoring sites include the Hawaii Ocean Time-series (HOT) program located 100 km to the north of the Hawaiian Islands.
Station ALOHA in the North Pacific, methane and nitrous oxide
in surface waters from 2008-2016 (Wilson et al., 2017)