Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements
Calculation of the sensible and latent heat (turbulent) fluxes is required in order to close the surface energy budget of glaciers and model glacial melt. The aerodynamic roughness length, z0, is a key parameter in the bulk approach to calculating sensible heat flux; yet, z0 is commonly considered s...
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American Geophysical Union
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ftleedsuniv:oai:eprints.whiterose.ac.uk:155071 2023-05-15T15:09:19+02:00 Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements Chambers, JR Smith, MW Quincey, DJ Carrivick, JL Ross, AN James, MR 2020-02 text https://eprints.whiterose.ac.uk/155071/ https://eprints.whiterose.ac.uk/155071/8/2019JF005167.pdf en eng American Geophysical Union https://eprints.whiterose.ac.uk/155071/8/2019JF005167.pdf Chambers, JR, Smith, MW orcid.org/0000-0003-4361-9527 , Quincey, DJ orcid.org/0000-0002-7602-7926 et al. (3 more authors) (2020) Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements. Journal of Geophysical Research, 125 (2). e2019JF005167. ISSN 0148-0227 Article NonPeerReviewed 2020 ftleedsuniv 2023-01-30T22:25:32Z Calculation of the sensible and latent heat (turbulent) fluxes is required in order to close the surface energy budget of glaciers and model glacial melt. The aerodynamic roughness length, z0, is a key parameter in the bulk approach to calculating sensible heat flux; yet, z0 is commonly considered simply as a tuning parameter or generalized between surfaces and over time. Spatially and temporally distributed observations of z0 over ice are rare. Both direct (from wind towers and sonic anemometers) and indirect (from microtopographic surveys) measurements of z0 are subject to sensitivities and uncertainties that are often unstated or overlooked. In this study, we present a quantitative evaluation of aerodynamic profile‐based and microtopographic methods and their effect on z0 using data collected from Storglaciären and Sydöstra Kaskasatjäkkaglaciären, Tarfala Valley, Arctic Sweden. Aggressive data filters discard most of the wind tower data, but still produce realistic z0 values of 1.9 mm and 2 mm. Despite uncertainty introduced by scale and resolution dependence, microtopographic methods produced estimates of z0 comparable to wind tower values and those found on similar surfaces. We conclude that: 1) in the absence of direct turbulent flux measurements from sonic anemometers, the profile and microtopographic methods provide realistic z0 values, 2) both 2D and 3D microtopographic methods are dependent on scale, resolution, and the chosen detrending method, and 3) careful calibration of these parameters could enable glacier‐wide investigations of z0 from remotely sensed data, including those increasingly available from satellite platforms. Article in Journal/Newspaper Arctic Tarfala White Rose Research Online (Universities of Leeds, Sheffield & York) Arctic Tarfala ENVELOPE(18.608,18.608,67.914,67.914) Storglaciären ENVELOPE(18.560,18.560,67.904,67.904) |
institution |
Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
description |
Calculation of the sensible and latent heat (turbulent) fluxes is required in order to close the surface energy budget of glaciers and model glacial melt. The aerodynamic roughness length, z0, is a key parameter in the bulk approach to calculating sensible heat flux; yet, z0 is commonly considered simply as a tuning parameter or generalized between surfaces and over time. Spatially and temporally distributed observations of z0 over ice are rare. Both direct (from wind towers and sonic anemometers) and indirect (from microtopographic surveys) measurements of z0 are subject to sensitivities and uncertainties that are often unstated or overlooked. In this study, we present a quantitative evaluation of aerodynamic profile‐based and microtopographic methods and their effect on z0 using data collected from Storglaciären and Sydöstra Kaskasatjäkkaglaciären, Tarfala Valley, Arctic Sweden. Aggressive data filters discard most of the wind tower data, but still produce realistic z0 values of 1.9 mm and 2 mm. Despite uncertainty introduced by scale and resolution dependence, microtopographic methods produced estimates of z0 comparable to wind tower values and those found on similar surfaces. We conclude that: 1) in the absence of direct turbulent flux measurements from sonic anemometers, the profile and microtopographic methods provide realistic z0 values, 2) both 2D and 3D microtopographic methods are dependent on scale, resolution, and the chosen detrending method, and 3) careful calibration of these parameters could enable glacier‐wide investigations of z0 from remotely sensed data, including those increasingly available from satellite platforms. |
format |
Article in Journal/Newspaper |
author |
Chambers, JR Smith, MW Quincey, DJ Carrivick, JL Ross, AN James, MR |
spellingShingle |
Chambers, JR Smith, MW Quincey, DJ Carrivick, JL Ross, AN James, MR Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements |
author_facet |
Chambers, JR Smith, MW Quincey, DJ Carrivick, JL Ross, AN James, MR |
author_sort |
Chambers, JR |
title |
Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements |
title_short |
Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements |
title_full |
Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements |
title_fullStr |
Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements |
title_full_unstemmed |
Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements |
title_sort |
glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements |
publisher |
American Geophysical Union |
publishDate |
2020 |
url |
https://eprints.whiterose.ac.uk/155071/ https://eprints.whiterose.ac.uk/155071/8/2019JF005167.pdf |
long_lat |
ENVELOPE(18.608,18.608,67.914,67.914) ENVELOPE(18.560,18.560,67.904,67.904) |
geographic |
Arctic Tarfala Storglaciären |
geographic_facet |
Arctic Tarfala Storglaciären |
genre |
Arctic Tarfala |
genre_facet |
Arctic Tarfala |
op_relation |
https://eprints.whiterose.ac.uk/155071/8/2019JF005167.pdf Chambers, JR, Smith, MW orcid.org/0000-0003-4361-9527 , Quincey, DJ orcid.org/0000-0002-7602-7926 et al. (3 more authors) (2020) Glacial aerodynamic roughness estimates: uncertainty, sensitivity and precision in field measurements. Journal of Geophysical Research, 125 (2). e2019JF005167. ISSN 0148-0227 |
_version_ |
1766340537221120000 |