YEAR-ROUND DETERMINATION OF METHANE (CH4) SOURCES AND SINKS IN ARCTIC LAKES USING CONTINUOUS AND AUTONOMOUS SAMPLING ...

• Main Author: McIntosh Marcek, Hadley
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Digital Repository at the University of Maryland 2020
• Subjects: Geochemistry; FOS Earth and related environmental sciences; Chemical oceanography; Diffusion; Lakes; Mackenzie Delta; Methane; OsmoSampler; Radiocarbon; Arctic
• Online Access: https://dx.doi.org/10.13016/luol-c9hv; http://drum.lib.umd.edu/handle/1903/26266

Methane (CH4) is a potent greenhouse gas and its concentration has been increasing in the atmosphere. While natural emissions from inland water bodies are known to be important, there is large uncertainty in the amount of methane released from lakes to the atmosphere, especially from Northern latitudes. Part of this is due to limited sampling in these systems during dynamic periods, such as ice-over and ice-melt. To better understand these temporal dynamics, I used autonomous, continuous samplers (OsmoSamplers) to collect lake water year-round over two years (2015-2017). Lake water was collected at a fine temporal resolution to provide time-integrated (~1 week) samples from multiple Arctic lakes within the Mackenzie Delta. The Mackenzie Delta is a lake-rich, productive environment that is expected to be a significant source of methane to the atmosphere. Lakes spanning the central delta and outer delta were sampled for methane concentration and stable carbon isotope ratio (δ13C-CH4) changes, ion ...