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Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions

Akerstrom, Frida
http://orcid.org/0000-0001-9476-3065
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354

Abstract Details

2016, MS, University of Cincinnati, Arts and Sciences: Geology.
Methane is a powerful greenhouse gas increasing in atmospheric concentration via multiple natural and anthropogenic sources. Climate warming may lead to increased emissions of methane from Arctic permafrost lakes via anaerobic organic matter respiration in a positive feedback to climate warming. In Arctic Alaska there is also a large reservoir of thermogenic methane from natural gas reserves under the cryosphere cap. We measured dissolved methane in 52 lakes on the North Slope of Alaska during August 2014 (average 1.2 ± 1.7 µg L-1;), April 2014 (280.7 ± 405.7 µg L-1;), and August of 2015 (3.1 ± 2.8 µg L-1;). Stable carbon and hydrogen isotope ratios of methane indicated that methane dissolved in lake water is biogenic, not derived from natural gas. Flux measurements were conducted in 16 lakes during August 2014 and 2015. Flux measurements were also measured diurnally over a three-week period in two lakes in August 2015. The average diffusive methane flux nearly doubled in August 2015 (13.0 ± 22.5 mg m-2; day-1;) versus August 2014 (7.1 ± 17.6 mg m2; day-1;); average lake temperatures were about 3°C warmer in summer 2015 than in summer 2014. Ebullition was only observed in 3 lakes, but ebullition fluxes were orders of magnitude higher than diffusive fluxes. During our intensive sampling in August 2015, diffusive fluxes did not significantly change on daily or weekly time scales, indicating that weekly flux measurements may be sufficient in future monitoring efforts to investigate potential carbon cycle – climate change feedbacks in Arctic lakes.
Amy Townsend-Small, Ph.D. (Committee Chair)
Kenneth Hinkel, Ph.D. (Committee Member)
Thomas Lowell, Ph.D. (Committee Member)
49 p.
Geology
Carbon Cycling; Climate Change; Thermokarst lakes; Alaska; Methane emissions; Permafrost

Recommended Citations

Citations

  • Akerstrom, F. (2016). Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions [Master's thesis, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354

    APA Style (7th edition)

  • Akerstrom, Frida. Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions. 2016. University of Cincinnati, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354.

    MLA Style (8th edition)

  • Akerstrom, Frida. "Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions." Master's thesis, University of Cincinnati, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354

    Chicago Manual of Style (17th edition)

ucin1479476238261354
178
© 2016, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.