Investigation of the behavior of dissolved gases during freezing

Lipp, G.; Körber, Ch.; Englich, S.; Hartmann, Ulrich; Rau, G.

doi:10.1016/0011-2240(87)90053-8

Cited by 42 publications

(44 citation statements)

References 25 publications

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“…Indeed, concentrations up to about 50% of this limit have been observed in the pore water underneath the freezing front in temperate peatlands [Melloh and Crill, 1996]. As the liquid water turns into ice, the dissolved CH 4 concentration in the remaining liquid water increases until the critical limit is reached and the dissolved CH 4 precipitates from the solution [Lipp et al, 1987]. The formed bubbles can then be pushed in front of the freezing front or get entrapped within it, depending on the speed of freezing [Lipp et al, 1987].…”

Section: Discussionmentioning

confidence: 99%

“…As the liquid water turns into ice, the dissolved CH 4 concentration in the remaining liquid water increases until the critical limit is reached and the dissolved CH 4 precipitates from the solution [Lipp et al, 1987]. The formed bubbles can then be pushed in front of the freezing front or get entrapped within it, depending on the speed of freezing [Lipp et al, 1987]. The bubble formation is, on the other hand, counteracted by a pressure dependence of CH 4 solubility, which increases by about 32 mg CH 4 L −1 bar −1 under typical soil pressures [Duan and Mao, 2006].…”

Section: Discussionmentioning

confidence: 99%

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Methane emission bursts from permafrost environments during autumn freeze‐in: New insights from ground‐penetrating radar

Pirk

Santos

Gustafson

et al. 2015

Geophysical Research Letters

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Large amounts of methane (CH4) are known to be emitted from permafrost environments during the autumn freeze‐in, but the specific soil conditions leading up to these bursts are unclear. Therefore, we used an ultrawide band ground‐penetrating radar in Northeast Greenland in autumn 2009 to estimate the volumetric composition inside the soil through dielectric characterization from 200 to 3200 MHz. Our results suggest a compression of the gas reservoir during the phase transition of soil water, which is accompanied by a peak in surface CH4 emissions. About 1 week thereafter, there seems to be a decompression event, consistent with ground cracking which allows the gas reservoir to expand again. This coincides with the largest CH4 emission, exceeding the summer maximum by a factor of 4. We argue that these complementary measurement techniques are needed to come to an understanding of tundra CH4 bursts connected to soil freezing.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Methane emission bursts from permafrost environments during autumn freeze‐in: New insights from ground‐penetrating radar

Pirk

Santos

Gustafson

et al. 2015

Geophysical Research Letters

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“…These can usually be distinguished from each other on the basis of their size, morphology, and gas content (Boereboom et al, 2012;Walter Anthony and Anthony, 2013). This study focuses on CH 4 which is stored in the form of bubbles from freeze-degassing, which are continuously formed at the advancing freezing front and occur in closely spaced layers in the ice cover (Lipp et al, 1987). Due to freeze-degassing dissolved gases enrich in a very thin water layer directly at the freezing front.…”

Section: Langer Et Al: Frozen Pondsmentioning

confidence: 99%

“…As soon as the bubbles are completely entrapped within the ice cover they are sealed from further gaseous exchange so that an enrichment of dissolved gases and bubble nucleation at the freezing front starts again. This results in the continuous formation of freeze-out bubble layers which preserve, to a certain degree, information about the concentration of the dissolved gases in the water column during the time of freezing (Lipp et al, 1987;Craig et al, 1992;Killawee et al, 1998). The frequency of bubble layer formation, bubble size, and bubble shape are largely dependent on the rate of freezing (Carte, 1961;Yoshimura et al, 2008).…”

Section: Langer Et Al: Frozen Pondsmentioning

confidence: 99%

Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta

et al. 2015

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Abstract. Lakes and ponds play a key role in the carbon cycle of permafrost ecosystems, where they are considered to be hotspots of carbon dioxide CO 2 and methane CH 4 emission. The strength of these emissions is, however, controlled by a variety of physical and biogeochemical processes whose responses to a warming climate are complex and only poorly understood. Small waterbodies have been attracting an increasing amount of attention since recent studies demonstrated that ponds can make a significant contribution to the CO 2 and CH 4 emissions of tundra ecosystems. Waterbodies also have a marked effect on the thermal state of the surrounding permafrost; during the freezing period they prolong the period of time during which thawed soil material is available for microbial decomposition.This study presents net CH 4 production rates during the freezing period from ponds within a typical lowland tundra landscape in northern Siberia. Rate estimations were based on CH 4 concentrations measured in surface lake ice from a variety of waterbody types. Vertical profiles along ice blocks showed an exponential increase in CH 4 concentration with depth. These CH 4 profiles were reproduced by a 1-D mass balance model and the net CH 4 production rates were then inferred through inverse modeling.Results revealed marked differences in early winter net CH 4 production among various ponds. Ponds situated within intact polygonal ground structures yielded low net production rates, of the order of 10 −11 to 10 −10 mol m −2 s −1 (0.01 to 0.14 mg CH 4 m −2 day −1 ). In contrast, ponds exhibiting clear signs of erosion yielded net CH 4 production rates of the order of 10 −7 mol m −2 s −1 (140 mg CH 4 m −2 day −1 ). Our results therefore indicate that once a particular threshold in thermal erosion has been crossed, ponds can develop into major CH 4 sources. This implies that any future warming of the climate may result in nonlinear CH 4 emission behavior in tundra ecosystems.

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“…Indeed, it has long been known that during freezing, air is released and often trapped as bubbles in the resultant ice. This phenomenon has important biological consequences in that bubble formation contributes to freezing damage in long-term preservation of cells and tissues (Carte et al 1961;Karlsson et al 1993;King et al 1974;Korber 1988;Kruuv 1985;Lipp et al 1987;Lipp et al 1994;Morris et al 1981;Steponkus et al 1981;Tao et al 2002;Toner et al 1990).…”

Section: Discussionmentioning

confidence: 99%

A Method to Co-Encapsulate Gas and Drugs in Liposomes for Ultrasound-Controlled Drug Delivery

Huang

McPherson

MacDonald

2008

Ultrasound in Medicine & Biology

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A novel method for the facile production of gas-containing liposomes with simultaneous drug encapsulation is described. Liposomes of phospholipid and cholesterol were prepared by conventional procedures of hydrating the lipid film, sonicating, freezing and thawing. A single, but critical modification of this procedure generates liposomes that contain gas (air, perfluorocarbon, argon); after sonication, the lipid is placed under pressure with the gas of interest. After equilibration, the sample is frozen. The pressure is then reduced to atmospheric and the suspension thawed. This procedure leads to entrapment of air in amounts up to 10% by volume by lipid dispersions at moderate (10mg/ml) concentrations of lipids. The amount of gas encapsulated increases with gas pressure and lipid concentration. Utilizing 0.32 M mannitol to provide an aqueous phase with physiological osmolarity, 1, 3, 6 or 9 atm of pressure was applied to 4 mg of lipid. This led to encapsulation of 10, 15, 20, and 30 l of gas in a total of 400 l of liposome dispersion (10mg lipids/ml), respectively. The mechanism for gas encapsulation presumably depends upon the fact that air (predominantly nitrogen and oxygen), like most solutes, dissolves poorly in ice and is excluded from the ice that forms during freezing. The excluded air then comes out of solution as air pockets that are stabilized in some form by a lipid coating. The presence of air in these preparations sensitizes them to ultrasound (1MHz, 8 W/cm 2 ,10 second) such that up to half of their aqueous contents (which could be a water soluble drug) can be released by short (10 s) applications of ultrasound. Both diagnostic and therapeutic applications of the method are conceivable.

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Investigation of the behavior of dissolved gases during freezing

Cited by 42 publications

References 25 publications

Methane emission bursts from permafrost environments during autumn freeze‐in: New insights from ground‐penetrating radar

Methane emission bursts from permafrost environments during autumn freeze‐in: New insights from ground‐penetrating radar

Frozen ponds: production and storage of methane during the Arctic winter in a lowland tundra landscape in northern Siberia, Lena River delta

A Method to Co-Encapsulate Gas and Drugs in Liposomes for Ultrasound-Controlled Drug Delivery

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