Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes

Martinez‐Cruz, Karla; Sepulveda‐Jauregui, Armando; Anthony, K. M. Walter; Thalasso, F.

doi:10.5194/bg-12-4595-2015

Cited by 84 publications

(60 citation statements)

References 65 publications

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“…In each of the study lakes, CH 4 concentrations are significantly higher under ice-covered conditions compared to open-water conditions (Fig. 7), which is also observed in other northern latitude lakes that are ice-covered the majority of the year (Juutinen et al, 2009;Martinez-Cruz et al, 2015). Ice cover impedes gas exchange between the water and the atmosphere, promoting buildup of CH 4 in the water column leading to increased CH 4 storage (Bastviken et al, 2004;Juutinen et al, 2009;Martinez-Cruz et al, 2015;Phelps et al, 1998).…”

Section: Implications For a Warmer Arcticsupporting

confidence: 58%

“…7), which is also observed in other northern latitude lakes that are ice-covered the majority of the year (Juutinen et al, 2009;Martinez-Cruz et al, 2015). Ice cover impedes gas exchange between the water and the atmosphere, promoting buildup of CH 4 in the water column leading to increased CH 4 storage (Bastviken et al, 2004;Juutinen et al, 2009;Martinez-Cruz et al, 2015;Phelps et al, 1998). No holes or moats were observed in the ice cover during sampling; therefore, the total inventory of CH 4 in the water column under ice-covered conditions was stored.…”

Section: Implications For a Warmer Arcticmentioning

confidence: 82%

“…8). Both the highest and lowest CH 4 concentrations are observed in waters < 5 • C. In freshwater environments, the concentration of dissolved CH 4 reflects the balance between CH 4 production and CH 4 consumption by anaerobic or aerobic oxidation (Duc et al, 2010;Dzyuban, 2010;Encinas Fernandez et al, 2014;Kankaala et al, 2007;Martinez-Cruz et al, 2015;Segarra et al, 2015;Smemo and Yavitt, 2011). Methane production is affected by temperature, where higher temperatures result in increased production (Duc et al, 2010).…”

Section: Effects Of Temperature On Chmentioning

confidence: 99%

“…Microbial production of CH 4 by methanogens is dependent upon anoxia, temperature, and the amount and quality of organic carbon substrates (Liikanen et al, 2003;Kankaala et al, 2006;Duc et al, 2010;Borrel et al, 2011). A large proportion of the CH 4 produced in lakes is consumed by aerobic or anaerobic oxidation (Frenzel et al, 1990;Bastviken et al, 2002;Kankaala et al, 2007;Dzyuban, 2010;Martinez-Cruz et al, 2015). Aerobic microbial oxidation of methane (MOx) depends on the availability of both CH 4 and O 2 , wherein higher MOx rates are usually found at the oxic-anoxic interface, where both CH 4 and O 2 are present in high concentrations (Bastviken et al, 2002;Dzyuban, 2010).…”

Section: Introductionmentioning

confidence: 99%

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Exceptional summer warming leads to contrasting outcomes for methane cycling in small Arctic lakes of Greenland

2017

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Abstract. In thermally stratified lakes, the greatest annual methane emissions typically occur during thermal overturn events. In July of 2012, Greenland experienced significant warming that resulted in substantial melting of the Greenland Ice Sheet and enhanced runoff events. This unusual climate phenomenon provided an opportunity to examine the effects of short-term natural heating on lake thermal structure and methane dynamics and compare these observations with those from the following year, when temperatures were normal. Here, we focus on methane concentrations within the water column of five adjacent small lakes on the icefree margin of southwestern Greenland under open-water and ice-covered conditions from 2012-2014. Enhanced warming of the epilimnion in the lakes under open-water conditions in 2012 led to strong thermal stability and the development of anoxic hypolimnia in each of the lakes. As a result, during open-water conditions, mean dissolved methane concentrations in the water column were significantly (p < 0.0001) greater in 2012 than in 2013. In all of the lakes, mean methane concentrations under ice-covered conditions were significantly (p < 0.0001) greater than under open-water conditions, suggesting spring overturn is currently the largest annual methane flux to the atmosphere. As the climate continues to warm, shorter ice cover durations are expected, which may reduce the winter inventory of methane and lead to a decrease in total methane flux during ice melt. Under openwater conditions, greater heat income and warming of lake surface waters will lead to increased thermal stratification and hypolimnetic anoxia, which will consequently result in increased water column inventories of methane. This stored methane will be susceptible to emissions during fall overturn, which may result in a shift in greatest annual efflux of methane from spring melt to fall overturn. The results of this study suggest that interannual variation in ground-level air temperatures may be the primary driver of changes in methane dynamics because it controls both the duration of ice cover and the strength of thermal stratification.

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Section: Implications For a Warmer Arcticsupporting

confidence: 58%

Section: Implications For a Warmer Arcticmentioning

confidence: 82%

Section: Effects Of Temperature On Chmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exceptional summer warming leads to contrasting outcomes for methane cycling in small Arctic lakes of Greenland

2017

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“…Nevertheless, the same order of magnitude of P 0 for three lakes of different genetic types with ecosystems functioning under drastically different climate conditions argues for robustness of our model formulation. A half-saturation constant for CH 4 , K CH 4 ,w = 3.75 × 10 −2 mol m −3 , was set close to upper estimate of this parameter, found in literature (Martinez-Cruz et al, 2015).…”

Section: Oxygen Methane and Carbon Dioxidesupporting

confidence: 82%

LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes

et al. 2016

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Abstract. A one-dimensional (1-D) model for an enclosed basin (lake) is presented, which reproduces temperature, horizontal velocities, oxygen, carbon dioxide and methane in the basin. All prognostic variables are treated in a unified manner via a generic 1-D transport equation for horizontally averaged property. A water body interacts with underlying sediments. These sediments are represented by a set of vertical columns with heat, moisture and CH 4 transport inside. The model is validated vs. a comprehensive observational data set gathered at Kuivajärvi Lake (southern Finland), demonstrating a fair agreement. The value of a key calibration constant, regulating the magnitude of methane production in sediments, corresponded well to that obtained from another two lakes. We demonstrated via surface seiche parameterization that the near-bottom turbulence induced by surface seiches is likely to significantly affect CH 4 accumulation there. Furthermore, our results suggest that a gas transfer through thermocline under intense internal seiche motions is a bottleneck in quantifying greenhouse gas dynamics in dimictic lakes, which calls for further research.

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Seasonal Dynamics of Dissolved Methane in Lakes of the Mackenzie Delta and the Role of Carbon Substrate Quality

2018

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Dissolved CH4 among lake waters of the Mackenzie River Delta was tracked in 2014 to assess how river‐to‐lake connection times, plus carbon substrate quantity and quality, affects the patterns and dynamics of CH4. An under‐ice survey of 29 lakes, three open‐water surveys of 43 lakes, and weekly surveys of 6 lakes revealed that CH4 among lake‐waters ranged from very high concentrations at the end of winter, with highest concentrations linked to shortest annual river connection times, to considerably lower concentrations as open water progressed, with a limited concentration range among lakes by late summer. Lakes most strongly affected by thermokarst varied irregularly from this pattern and did not have the highest CH4 concentrations. CH4 among lake waters was generally related to measures of carbon substrate quantity, where relations with macrophyte biomass and dissolved organic carbon in lake water were statistically stronger than % organic matter within the lake sediments. CH4 was also directly related to the molecular weight (a[250]:a[365]) of dissolved organic matter at the end of winter, but was inversely related to this measure during open water. Carbon quality per se, after accounting for differences in carbon quantity (macrophyte biomass, dissolved organic carbon concentrations, or organic content of lake sediments), appears to play a significant role in controlling CH4 concentrations among the lake waters, particularly during winter ice cover. Carbon quality in lake sediments and of dissolved organic matter in winter lake waters appears to be as important as thermokarst augmentation of carbon quantity for enhancing methanogenesis in this lake‐rich Arctic system.

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Geographic and seasonal variation of dissolved methane and aerobic methane oxidation in Alaskan lakes

Cited by 84 publications

References 65 publications

Exceptional summer warming leads to contrasting outcomes for methane cycling in small Arctic lakes of Greenland

Exceptional summer warming leads to contrasting outcomes for methane cycling in small Arctic lakes of Greenland

LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes

Seasonal Dynamics of Dissolved Methane in Lakes of the Mackenzie Delta and the Role of Carbon Substrate Quality

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