Sensitivity of the interpretation of the experimental ion thermal diffusivity to the determination of the ion conductive heat flux

The aim of the paper is to describe a new, rapid transient method for the determination of thermal diffusivity and thermal conductivity of rocks. The present transient method is based on the application of a constant heat flux to the top surface of a block of rock that is insulated on all other surfaces. Results of a sensitivity analysis of the method indicate that thermal diffusivity can be measured to a best accuracy of about 3 percent, and thermal conductivity of saturated rocks can be determined to a best accuracy of about 8 percent. The method provides estimates of thermal conductivity that are consistent with estimates made using the steady‐state divided‐bar apparatus. The method is applied to determine the thermal conductivity of a suite of rocks from western Australian sedimentary basins.

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Variations of ablation, albedo and energy balance at the margin of the Greenland ice sheet, Kronprins Christian Land, eastern north Greenland

Journal of Glaciology ◽

10.3189/s002214300001786x ◽

1995 ◽

Vol 41 (137) ◽

pp. 174-182 ◽

Cited By ~ 2

Author(s):

Thomas Konzelmann ◽

Roger J. Braithwaite

Keyword(s):

Heat Flux ◽

Energy Balance ◽

Latent Heat ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Small Scale ◽

Conductive Heat ◽

Net Radiation ◽

Conductive Heat Flux ◽

North Greenland

AbstractA meteorological and glaciological experiment was carried out in July 1993 at the margin of the Greenland ice sheet in Kronprins Christian Land, eastern north Greenland. Within a small area (about 100 m2) daily measurements were made on ten ablation stakes fixed in “light” and “dark” ice and were compared to each other. Simultaneously, the components of the energy balance, including net radiation, sensible-heat flux, latent-heat flux and conductive-heat flux in the ice were determined. Global radiation, longwave incoming radiation and albedo were measured, and longwave outgoing radiation was calculated by assuming that the glacier surface was melting. Sensible-and latent-heat fluxes were calculated from air temperature, humidity and wind speed. Conductive-heat flux in the ice was estimated by temperature-profile measurements in the uppermost ice layer. Net radiation is the major source of ablation energy, and turbulent fluxes are smaller energy sources by about three times, while heat flux into the ice is a substantial heat sink, reducing energy available for ice melt. Albedo varies from 0.42 to 0.56 within the experimental site and causes relatively large differences in ablation at stakes close to each other. Small-scale albedo variations should therefore be carefully sampled for large-scale energy-balance calculations.

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Lumped System Analysis on the Lunar Surface Temperature Using the Bottom Conductive Heat Flux Model

Journal of the Korean Society for Aeronautical & Space Sciences ◽

10.5139/jksas.2019.47.1.66 ◽

2019 ◽

Vol 47 (1) ◽

pp. 66-74

Author(s):

Taig Young Kim

Keyword(s):

Heat Flux ◽

Surface Temperature ◽

Lunar Surface ◽

System Analysis ◽

Conductive Heat ◽

Conductive Heat Flux ◽

Flux Model ◽

Heat Flux Model

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Observations and modelling of first-year ice growth and simultaneous second-year ice ablation in the Prydz Bay, East Antarctica

Annals of Glaciology ◽

10.1017/aog.2017.33 ◽

2017 ◽

Vol 58 (75pt1) ◽

pp. 59-67 ◽

Cited By ~ 6

Author(s):

Jiechen Zhao ◽

Bin Cheng ◽

Qinghua Yang ◽

Timo Vihma ◽

Lin Zhang

Keyword(s):

Heat Flux ◽

Temperature Gradient ◽

East Antarctica ◽

Prydz Bay ◽

Large Temperature ◽

First Year ◽

Conductive Heat ◽

Oceanic Heat Flux ◽

Conductive Heat Flux ◽

Second Year

ABSTRACT The seasonal cycle of fast ice thickness in Prydz Bay, East Antarctica, was observed between March and December 2012. In March, we observed a 0.16 m thickness gain of 0.22 m-thick first-year ice (FYI), while 1.16 m-thick second-year ice (SYI) nearby simultaneously ablated by 0.59 m. A 1-D thermodynamic sea-ice model was applied to identify the factors that led to the simultaneous growth of FYI and melt of SYI. The different evolutions were explained by the difference in the conductive heat flux between the FYI and SYI. As the FYI was thin, there was a large temperature gradient between the ice base and the colder ice surface. This generated an upward conductive heat flux, which was larger than the heat flux from the ocean to the ice base, yielding basal growth of ice. In the case of the thicker SYI the temperature gradient and, hence, the conductive heat flux were smaller, and not sufficient to balance the oceanic heat flux at the ice base, yielding basal ablation. Penetration of solar radiation affected the conductive heat flux in both cases, and the model results were sensitive to the initial ice temperature profile and the uncertainty of the oceanic heat flux.

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