Permanent Ice Covers of the Mcmurdo Dry Valley Lakes, Antarctica: Bubble Formation and Metamorphism

Adams, Edward; Priscu, John C.; Fritsen, Christian H.; Smith, Scott; Brackman, Steven L.

doi:10.1029/ar072p0281

Cited by 33 publications

(28 citation statements)

References 10 publications

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“…This is consistent with observations of CH 4 concentrations in boreal lake ice 10 to 100 times lower than in the underlying water column (Phelps et al, 1998). In some cases, the exclusion of dissolved CH 4 from downward-growing ice leads to the formation of millimeter-scale-diameter tubular bubbles within ice (Adams et al, 2013;Boereboom et al, 2012). Such bubbles were not obvious to us in ice blocks from Goldstream Lake, so the model did not include this process.…”

Section: Water Column Dissolved Gasessupporting

confidence: 72%

Modeling the impediment of methane ebullition bubbles by seasonal lake ice

et al. 2014

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Abstract. Microbial methane (CH 4 ) ebullition (bubbling) from anoxic lake sediments comprises a globally significant flux to the atmosphere, but ebullition bubbles in temperate and polar lakes can be trapped by winter ice cover and later released during spring thaw. This "ice-bubble storage" (IBS) constitutes a novel mode of CH 4 emission. Before bubbles are encapsulated by downward-growing ice, some of their CH 4 dissolves into the lake water, where it may be subject to oxidation. We present field characterization and a model of the annual CH 4 cycle in Goldstream Lake, a thermokarst (thaw) lake in interior Alaska. We find that summertime ebullition dominates annual CH 4 emissions to the atmosphere. Eighty percent of CH 4 in bubbles trapped by ice dissolves into the lake water column in winter, and about half of that is oxidized. The ice growth rate and the magnitude of the CH 4 ebullition flux are important controlling factors of bubble dissolution. Seven percent of annual ebullition CH 4 is trapped as IBS and later emitted as ice melts. In a future warmer climate, there will likely be less seasonal ice cover, less IBS, less CH 4 dissolution from trapped bubbles, and greater CH 4 emissions from northern lakes.

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Section: Water Column Dissolved Gasessupporting

confidence: 72%

Modeling the impediment of methane ebullition bubbles by seasonal lake ice

et al. 2014

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“…Oxygen is released into solution during the melting of glacier ice, which contains bubbles of atmospheric gas. Oxygen also accumulates in solution during freezing, since gas is excluded from growing ice crystals (Adams et al , 1998) and during periods of net photosynthesis. Oxygen is removed from solution during periods of net respiration and oxidation of minerals containing reduced S (IV) and Fe (II) species (Tranter et al , 2002).…”

Section: Discussionmentioning

confidence: 99%

“… Bubble formation in Dry Valley lake ice covers (Adams et al , 1998). Bubbles form a characteristic teardrop shape, thought to also occur when cryoconite holes freeze from the sides and base …”

Section: Discussionmentioning

confidence: 99%

High‐resolution monitoring reveals dissolved oxygen dynamics in an Antarctic cryoconite hole

Bagshaw

Tranter

Wadham

et al. 2011

Hydrological Processes

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Abstract:This study presents the first high-resolution dataset of dissolved oxygen (DO) measurements in an ice-lidded cryoconite hole on Canada Glacier, McMurdo Dry Valleys, Antarctica. Fibre optic DO minisensors were installed in a cryoconite hole prior to seasonal internal melting and hydrological connection to the subsurface drainage system. Oxygen air saturation in the cryoconite hole typically ranged from 50 to 80%, in broad agreement with previous single measurements, indicating net respiration (R). This is consistent with results of simple incubation experiments performed in the field. Simultaneous time series for electrical conductivity, water temperature, and DO over the four-week study period provide information regarding the connectivity of cryoconite holes with the near-surface drainage system. The main driver of the observed variations in DO is likely to be periodic melt-freeze cycles. We conclude that automated sensing techniques, such as those described here, when used in conjunction with physical measurements, have great potential for high-resolution monitoring of the factors that perturb biogeochemical processes in cryospheric surface aquatic ecosystems.

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“…Bubble formation processes and shapes in lake ice have already been discussed at length by several authors (Adams et al, 1998;Bari and Hallett, 1974;Carte, 1961;Gow and Langston, 1977). These authors suggest that bubble shapes and density result from a balance between ice growth rate and diffusion of rejected gases in the liquid reservoir ahead.…”

Section: A New Lake Ice Type Classification Based On Bubbles Propertiesmentioning

confidence: 99%

Gas properties of winter lake ice in Northern Sweden: implication for carbon gas release

et al. 2012

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Abstract. This paper describes gas composition, total gas content and bubbles characteristics in winter lake ice for four adjacent lakes in a discontinuous permafrost area. Our gas mixing ratios for O 2 , N 2 , CO 2 , and CH 4 suggest that gas exchange occurs between the bubbles and the water before entrapment in the ice. Comparison between lakes enabled us to identify 2 major "bubbling events" shown to be related to a regional drop of atmospheric pressure. Further comparison demonstrates that winter lake gas content is strongly dependent on hydrological connections: according to their closed/open status with regards to water exchange, lakes build up more or less greenhouse gases (GHG) in their water and ice cover during the winter, and release it during spring melt. These discrepancies between lakes need to be taken into account when establishing a budget for permafrost regions. Our analysis allows us to present a new classification of bubbles, according to their gas properties. Our methane emission budgets (from 6.52 10 −5 to 12.7 mg CH 4 m −2 d −1 at 4 different lakes) for the three months of winter ice cover is complementary to other budget estimates, as our approach encompasses inter-and intra-lake variability.Most available studies on boreal lakes have focused on quantifying GHG emissions from sediment by means of various systems collecting gases at the lake surface, and this mainly during the summer "open water" period. Only few of these have looked at the gas enclosed in the winter ice-cover itself. Our approach enables us to integrate, for the first time, the history of winter gas emission for this type of lakes.

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Permanent Ice Covers of the Mcmurdo Dry Valley Lakes, Antarctica: Bubble Formation and Metamorphism

Cited by 33 publications

References 10 publications

Modeling the impediment of methane ebullition bubbles by seasonal lake ice

Modeling the impediment of methane ebullition bubbles by seasonal lake ice

High‐resolution monitoring reveals dissolved oxygen dynamics in an Antarctic cryoconite hole

Gas properties of winter lake ice in Northern Sweden: implication for carbon gas release

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