Results of the Imager for Mars Pathfinder windsock experiment

Robert Sullivan, Ronald Greeley, Michael Kraft, Gregory Wilson, Matthew Golombek, Ken Herkenhoff, James Murphy, Peter Smith

Research output: Contribution to journalArticle

67 Citations (Scopus)

Abstract

The Imager for Mars Pathfinder (IMP) windsock experiment measured wind speeds at three heights within 1.2 m of the Martian surface during Pathfinder landed operations. These wind data allowed direct measurement of near-surface wind profiles on Mars for the first time, including determination of aerodynamic roughness length and wind friction speeds. Winds were light during periods of windsock imaging, but data from the strongest breezes indicate aerodynamic roughness length of 3 cm at the landing site, with wind friction speeds reaching 1 m/s. Maximum wind friction speeds were about half of the threshold-of-motion friction speeds predicted for loose, fine-grained materials on smooth Martian terrain and about one third of the threshold-of-motion friction speeds predicted for the same size particles over terrain with aerodynamic roughness of 3 cm. Consistent with this, and suggesting that low wind speeds prevailed when the windsock array was not imaged and/or no particles were available for aeolian transport, no wind-related changes to the surface during mission operations have been recognized. The aerodynamic roughness length reported here implies that proposed deflation of fine particles around the landing site, or activation of duneforms seen by IMP and Sojourner, would require wind speeds >28 m/s at the Pathfinder top windsock height (or >31 m/s at the equivalent Viking wind sensor height of 1.6 m) and wind speeds >45 m/s above 10 m. These wind speeds would cause rock abrasion if a supply of durable particles were available for saltation. Previous analyses indicate that the Pathfinder landing site probably is rockier and rougher than many other plains units on Mars, so aerodynamic roughness length elsewhere probably is less than the 3-cm value reported for the Pathfinder site.

Original languageEnglish (US)
Pages (from-to)24547-24562
Number of pages16
JournalJournal of Geophysical Research: Space Physics
Volume105
Issue numberE10
StatePublished - Oct 25 2000

Fingerprint

Mars Pathfinder
Image sensors
aerodynamics
roughness
friction
wind velocity
experiment
Experiments
landing sites
Aerodynamics
Surface roughness
Friction
Mars
Landing
saltation
deflation
wind profile
mars
abrasion
surface wind

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)
  • Atmospheric Science
  • Geochemistry and Petrology
  • Geophysics
  • Oceanography
  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Sullivan, R., Greeley, R., Kraft, M., Wilson, G., Golombek, M., Herkenhoff, K., ... Smith, P. (2000). Results of the Imager for Mars Pathfinder windsock experiment. Journal of Geophysical Research: Space Physics, 105(E10), 24547-24562.

Results of the Imager for Mars Pathfinder windsock experiment. / Sullivan, Robert; Greeley, Ronald; Kraft, Michael; Wilson, Gregory; Golombek, Matthew; Herkenhoff, Ken; Murphy, James; Smith, Peter.

In: Journal of Geophysical Research: Space Physics, Vol. 105, No. E10, 25.10.2000, p. 24547-24562.

Research output: Contribution to journalArticle

Sullivan, R, Greeley, R, Kraft, M, Wilson, G, Golombek, M, Herkenhoff, K, Murphy, J & Smith, P 2000, 'Results of the Imager for Mars Pathfinder windsock experiment', Journal of Geophysical Research: Space Physics, vol. 105, no. E10, pp. 24547-24562.
Sullivan R, Greeley R, Kraft M, Wilson G, Golombek M, Herkenhoff K et al. Results of the Imager for Mars Pathfinder windsock experiment. Journal of Geophysical Research: Space Physics. 2000 Oct 25;105(E10):24547-24562.
Sullivan, Robert ; Greeley, Ronald ; Kraft, Michael ; Wilson, Gregory ; Golombek, Matthew ; Herkenhoff, Ken ; Murphy, James ; Smith, Peter. / Results of the Imager for Mars Pathfinder windsock experiment. In: Journal of Geophysical Research: Space Physics. 2000 ; Vol. 105, No. E10. pp. 24547-24562.
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