Surface Roughness and Bulk Heat Transfer on a Glacier: Comparison with Eddy Correlation

Abstract More than 100 simultaneously measured profiles of wind speed and temperature were analyzed to determine the aerodynamic and thermal roughness lengths of glacier ice. The results proved to be extremely sensitive to measurement height, which is difficult to define precisely on the hummocky te...

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Bibliographic Details
Published in:Journal of Glaciology
Main Author: Munro, D. Scott
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 1989
Subjects:
Online Access:http://dx.doi.org/10.1017/s0022143000009266
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000009266
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Summary:Abstract More than 100 simultaneously measured profiles of wind speed and temperature were analyzed to determine the aerodynamic and thermal roughness lengths of glacier ice. The results proved to be extremely sensitive to measurement height, which is difficult to define precisely on the hummocky terrain of a glacier. Therefore, aerodynamic roughness lengths were estimated from the microtopography of the surface, yielding 2.46 mm for ice, and 5.5 mm for snow. Despite the indeterminate nature of the profile analysis, it did support the view that the thermal roughness length must decrease as the roughness Reynolds number increases, a relationship which has been modelled in the literature. Good agreement between bulk-transfer estimates and eddy-correlation measurements of fhe sensible heat-flux density on melting ice and snow was obtained by combining the aerodynamic roughness length with a suitable model for thermal roughness length.