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

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

Bibliographic Details
Main Author: Akerstrom, Frida
Language:English
Published: University of Cincinnati / OhioLINK 2016
Subjects:
Geology
Carbon Cycling
Climate Change
Thermokarst lakes
Alaska
Methane emissions
Permafrost
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-ucin14794762382613542021-08-03T06:38:56Z Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions Akerstrom, Frida Geology Carbon Cycling Climate Change Thermokarst lakes Alaska Methane emissions Permafrost 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<sup>-2</sup>; day<sup>-1</sup>;) versus August 2014 (7.1 ± 17.6 mg m<sup>2</sup>; 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. 2016 English text University of Cincinnati / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354 http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Geology
Carbon Cycling
Climate Change
Thermokarst lakes
Alaska
Methane emissions
Permafrost
spellingShingle Geology
Carbon Cycling
Climate Change
Thermokarst lakes
Alaska
Methane emissions
Permafrost
Akerstrom, Frida
Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions
author Akerstrom, Frida
author_facet Akerstrom, Frida
author_sort Akerstrom, Frida
title Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions
title_short Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions
title_full Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions
title_fullStr Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions
title_full_unstemmed Carbon Cycling-Climate Change Feedback in Lakes in Arctic Alaska: Monitoring Methane Emissions
title_sort carbon cycling-climate change feedback in lakes in arctic alaska: monitoring methane emissions
publisher University of Cincinnati / OhioLINK
publishDate 2016
url http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479476238261354
work_keys_str_mv AT akerstromfrida carboncyclingclimatechangefeedbackinlakesinarcticalaskamonitoringmethaneemissions
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