the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Yardangs and Dunes: Minimum- and Maximum-Dissipation Aeolian Landforms
Abstract. Yardangs are ridges formed in soft rock by aeolian erosion in a unidirectional wind environment, and often have a 4 : 1 length : width ratio that is associated with a minimum-drag shape for a given width. Dunes are emergent aeolian landforms formed by accumulation and removal of sand particles. Dunes have a range of morphologies (barchans, stars, linear, transverse etc.) which can be mapped to the sand supply and the diversity of wind directions. The dune pattern that generally emerges is one that maximizes gross bedform normal transport (GBNT). For fixed imposed wind speed, a minimum drag force corresponds to a minimum dissipation, whereas maximum sand transport corresponds to maximum dissipation. These examples illuminate a more general paradox in non-equilibrium thermodynamics, wherein entropy production rates may be maximized or minimized depending, vaguely, on the degrees of freedom in the system. In these geomorphological examples, however, the difference is informatively clear: whereas yardangs emerge simply by removal of material alone and dissipation is minimized, dunes form by the much less constrained removal and accumulation to maximize dissipation.
This preprint has been withdrawn.
-
Withdrawal notice
This preprint has been withdrawn.
-
Preprint
(537 KB)
Interactive discussion
- SC1: 'Chief Editor comment', Axel Kleidon, 05 Dec 2019
-
RC1: 'Review of "Yardangs and dunes: Minimum- and maximum-dissipation aeolian landforms"', Hisashi Ozawa, 21 Jan 2020
- AC1: 'MaxEP is the only 'true' steady state?', Ralph Lorenz, 24 Jan 2020
-
RC2: 'Interactive comment on “Yardangs and Dunes: Minimum- and Maximum-Dissipation Aeolian Landforms” by Ralph D. Lorenz', Anonymous Referee #2, 23 Feb 2020
- AC2: 'Good review', Ralph Lorenz, 30 Mar 2020
Interactive discussion
- SC1: 'Chief Editor comment', Axel Kleidon, 05 Dec 2019
-
RC1: 'Review of "Yardangs and dunes: Minimum- and maximum-dissipation aeolian landforms"', Hisashi Ozawa, 21 Jan 2020
- AC1: 'MaxEP is the only 'true' steady state?', Ralph Lorenz, 24 Jan 2020
-
RC2: 'Interactive comment on “Yardangs and Dunes: Minimum- and Maximum-Dissipation Aeolian Landforms” by Ralph D. Lorenz', Anonymous Referee #2, 23 Feb 2020
- AC2: 'Good review', Ralph Lorenz, 30 Mar 2020
Viewed
HTML | XML | Total | BibTeX | EndNote | |
---|---|---|---|---|---|
873 | 425 | 75 | 1,373 | 95 | 99 |
- HTML: 873
- PDF: 425
- XML: 75
- Total: 1,373
- BibTeX: 95
- EndNote: 99
Viewed (geographical distribution)
Country | # | Views | % |
---|
Total: | 0 |
HTML: | 0 |
PDF: | 0 |
XML: | 0 |
- 1
Ralph D. Lorenz
freeand maximize sand transport or work. Yardangs form only by erosion, are more constrained, and emerge with streamlined shape, minimizing work.