Dynamic flows create potentially habitable conditions in Antarctic subglacial lakes
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In this paper, the authors demonstrate that most subglacial lakes are in a regime of vigorous turbulent vertical convection, enabling suspension of spherical particulates with diameters up to 36 micrometers.Abstract:
Trapped beneath the Antarctic ice sheet lie over 400 subglacial lakes, which are considered to be extreme, isolated, yet viable habitats for microbial life. The physical conditions within subglacial lakes are critical to evaluating how and where life may best exist. Here, we propose that Earth’s geothermal flux provides efficient stirring of Antarctic subglacial lake water. We demonstrate that most lakes are in a regime of vigorous turbulent vertical convection, enabling suspension of spherical particulates with diameters up to 36 micrometers. Thus, dynamic conditions support efficient mixing of nutrient- and oxygen-enriched meltwater derived from the overlying ice, which is essential for biome support within the water column. We caution that accreted ice analysis cannot always be used as a proxy for water sampling of lakes beneath a thin (read more
Citations
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Anomalous Convective Flows Carve Pinnacles and Scallops in Melting Ice
TL;DR: In this paper , the shape dynamics of ice suspended in cold fresh water and subject to the natural convective flows generated during melting were investigated. And they showed that the morphology of melted ice is a sensitive indicator of ambient temperature, which is closely linked to the anomalous density-temperature profile of liquid water.
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Universal properties of penetrative turbulent Rayleigh-Bénard convection
TL;DR: In this paper, the authors provided theoretical models to predict the universal relationship between the center temperature and the normalized Nusselt number with the density inversion parameter and provided theoretical analysis to predict these universal relationships.
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Universal properties of penetrative turbulent Rayleigh--B\'enard convection in cold water near $4^\circ\rm{C}$
TL;DR: In this article, the authors theoretically derived the universal (i.e., $Ra$-independent) dependence of the density inversion parameter (1+\theta_m^2)/2.
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Turbulent convection in subglacial lakes
TL;DR: In this article, the authors used two-dimensional direct numerical simulations to investigate the characteristic temperature fluctuations and velocities in freshwater subglacial lakes as functions of the ice overburden pressure.
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Morphology evolution of a melting solid layer above its melt heated from below
TL;DR: In this article , Wang et al. showed that the interface roughness amplitude scales with the mean height of the liquid layer and derived this scaling relation from the Stefan boundary condition and relate it to the non-uniform distribution of heat flux at the interface.
References
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