Double-diffusive convection in Lake Kivu.
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In this paper, double-diffusive staircases with a total of 230-350 mixed layers and sharp interfaces were observed in nine microstructure temperature profiles measured during February 2004 in Lake Kivu.Abstract:
Double-diffusive staircases with a total of 230-350 mixed layers and sharp interfaces were observed in nine microstructure temperature profiles measured during February 2004 in Lake Kivu. The presence of these staircases at depths. 120 m indicates that diapycnal turbulent mixing is weak and vertical diffusive transport is dominated by double diffusion. Contrary to previously investigated natural or laboratory double-diffusive systems, the dissolved gases CO(2) and CH(4) contribute significantly to the density stratification, thereby influencing the formation and the structure of the staircases. The density ratio (i.e., the ratio of the stabilizing effect of dissolved substances to the destabilizing effect of temperature) ranges between 2.0 and 4.5 in large sections of the deep waters, implying a high susceptibility to the formation of staircases. The mixed layers (average thickness 0.48 m) are shown to be in a state of active convection. The average thickness of the interfaces (0.18 m) is surprisingly constant and independent of the large-scale stratification. The vertical heat fluxes correlate well with the temperature steps across the interfaces. Lake Kivu receives inflows from subaquatic springs at several depths that maintain the large-scale structure of the density stratification and disturb the staircases. In comparison to earlier observations from 1972, the double-diffusive heat fluxes appear to have been reduced, leading to a heat accumulation in the deep waters. Conversely, the strengthening of the main chemocline indicates an increased discharge of the subaquatic springs that could be responsible for recent changes in the nutrient cycling and methane production in the lake.read more
Citations
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Property impacts on Carbon Capture and Storage (CCS) processes: A review
TL;DR: The knowledge of thermodynamic and transport properties of CO2-mixtures is important for designing and operating different processes in carbon capture and storage systems as mentioned in this paper, and a literature survey is presented in this paper.
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Methane sources and sinks in Lake Kivu
Natacha Pasche,Natacha Pasche,Martin Schmid,Francisco Vazquez,Carsten J. Schubert,Alfred Wüest,Alfred Wüest,John D. Kessler,Mary A. Pack,William S. Reeburgh,Helmut Bürgmann +10 more
TL;DR: A recent study reported that CH 4 concentrations in Lake Kivu have increased by up to 15% in the last 30 years and that accumulation at this rate could lead to catastrophic outgassing by ∼2100 as mentioned in this paper.
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LakeMIP Kivu: Evaluating the representation of a large, deep tropical lake by a set of one-dimensional lake models
Wim Thiery,Victor Stepanenko,Xing Fang,Klaus Jöhnk,Zhongshun Li,Andrey Martynov,Marjorie Perroud,Z. M. Subin,François Darchambeau,Dmitrii Mironov,Nicole Van Lipzig +10 more
TL;DR: In this paper, for the first time, a set of one-dimensional lake models are evaluated for Lake Kivu (2.28°S; 28.98°E), East Africa.
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Magma sources involved in the 2002 Nyiragongo eruption, as inferred from an InSAR analysis
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Understanding the performance of the FLake model over two African Great Lakes
Wim Thiery,Andrey Martynov,Andrey Martynov,François Darchambeau,Jean-Pierre Descy,Pierre-Denis Plisnier,Laxmi Sushama,N. P. M. van Lipzig +7 more
TL;DR: In this paper, the ability of the one-dimensional lake model FLake to represent the mixolimnion temperatures for tropical conditions was tested for three locations in East Africa: Lake Kivu and Lake Tanganyika's northern and southern basins.
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