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Jens Jacob Iversen

A lower-than-expected saltation threshold at Martian pressure and below

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A lower-than-expected saltation threshold at Martian pressure and below. / Andreotti, Bruno; Claudin, Philippe; Iversen, Jens Jacob; Merrison, Jonathan P.; Rasmussen, Keld R.

I: Proceedings of the National Academy of Sciences of the United States of America, Bind 118, Nr. 5, e2012386118, 02.2021.

Publikation: Bidrag til tidsskrift/Konferencebidrag i tidsskrift /Bidrag til avisTidsskriftartikelForskningpeer review

Harvard

Andreotti, B, Claudin, P, Iversen, JJ, Merrison, JP & Rasmussen, KR 2021, 'A lower-than-expected saltation threshold at Martian pressure and below', Proceedings of the National Academy of Sciences of the United States of America, bind 118, nr. 5, e2012386118. https://doi.org/10.1073/pnas.2012386118

APA

Andreotti, B., Claudin, P., Iversen, J. J., Merrison, J. P., & Rasmussen, K. R. (2021). A lower-than-expected saltation threshold at Martian pressure and below. Proceedings of the National Academy of Sciences of the United States of America, 118(5), [e2012386118]. https://doi.org/10.1073/pnas.2012386118

CBE

Andreotti B, Claudin P, Iversen JJ, Merrison JP, Rasmussen KR. 2021. A lower-than-expected saltation threshold at Martian pressure and below. Proceedings of the National Academy of Sciences of the United States of America. 118(5):Article e2012386118. https://doi.org/10.1073/pnas.2012386118

MLA

Andreotti, Bruno o.a.. "A lower-than-expected saltation threshold at Martian pressure and below". Proceedings of the National Academy of Sciences of the United States of America. 2021. 118(5). https://doi.org/10.1073/pnas.2012386118

Vancouver

Andreotti B, Claudin P, Iversen JJ, Merrison JP, Rasmussen KR. A lower-than-expected saltation threshold at Martian pressure and below. Proceedings of the National Academy of Sciences of the United States of America. 2021 feb;118(5). e2012386118. https://doi.org/10.1073/pnas.2012386118

Author

Andreotti, Bruno ; Claudin, Philippe ; Iversen, Jens Jacob ; Merrison, Jonathan P. ; Rasmussen, Keld R. / A lower-than-expected saltation threshold at Martian pressure and below. I: Proceedings of the National Academy of Sciences of the United States of America. 2021 ; Bind 118, Nr. 5.

Bibtex

@article{184850cf39e140e49eac5e130541f115,
title = "A lower-than-expected saltation threshold at Martian pressure and below",
abstract = "Aeolian sediment transport is observed to occur on Mars as well as other extraterrestrial environments, generating ripples and dunes as on Earth. The search for terrestrial analogs of planetary bedforms, as well as environmental simulation experiments able to reproduce their formation in planetary conditions, are powerful ways to question our understanding of geomorphological processes toward unusual environmental conditions. Here, we perform sediment transport laboratory experiments in a closed-circuit wind tunnel placed in a vacuum chamber and operated at extremely low pressures to show that Martian conditions belong to a previously unexplored saltation regime. The threshold wind speed required to initiate saltation is only quantitatively predicted by state-of-the art models up to a density ratio between grain and air of 4 × 105 but unexpectedly falls to much lower values for higher density ratios. In contrast, impact ripples, whose emergence is continuously observed on the granular bed over the whole pressure range investigated, display a characteristic wavelength and propagation velocity essentially independent of pressure. A comparison of these findings with existing models suggests that sediment transport at low Reynolds number but high grain-to-fluid density ratio may be dominated by collective effects associated with grain inertia in the granular collisional layer.",
keywords = "Impact ripples, Mars, Saltation at low pressure, Sediment transport threshold",
author = "Bruno Andreotti and Philippe Claudin and Iversen, {Jens Jacob} and Merrison, {Jonathan P.} and Rasmussen, {Keld R.}",
note = "Funding Information: ACKNOWLEDGMENTS. This work has been funded by Europlanet grant 11376. Europlanet 2020 Research Infrastructure has received funding from the European Union{\textquoteright}s Horizon 2020 research and innovation program under grant agreement 654208. We are grateful to R. C. Ewing for providing walnut shell samples for a new measurement of their bulk density. Publisher Copyright: {\textcopyright} 2021 National Academy of Sciences. All rights reserved. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.",
year = "2021",
month = feb,
doi = "10.1073/pnas.2012386118",
language = "English",
volume = "118",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "The National Academy of Sciences of the United States of America",
number = "5",

}

RIS

TY - JOUR

T1 - A lower-than-expected saltation threshold at Martian pressure and below

AU - Andreotti, Bruno

AU - Claudin, Philippe

AU - Iversen, Jens Jacob

AU - Merrison, Jonathan P.

AU - Rasmussen, Keld R.

N1 - Funding Information: ACKNOWLEDGMENTS. This work has been funded by Europlanet grant 11376. Europlanet 2020 Research Infrastructure has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement 654208. We are grateful to R. C. Ewing for providing walnut shell samples for a new measurement of their bulk density. Publisher Copyright: © 2021 National Academy of Sciences. All rights reserved. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/2

Y1 - 2021/2

N2 - Aeolian sediment transport is observed to occur on Mars as well as other extraterrestrial environments, generating ripples and dunes as on Earth. The search for terrestrial analogs of planetary bedforms, as well as environmental simulation experiments able to reproduce their formation in planetary conditions, are powerful ways to question our understanding of geomorphological processes toward unusual environmental conditions. Here, we perform sediment transport laboratory experiments in a closed-circuit wind tunnel placed in a vacuum chamber and operated at extremely low pressures to show that Martian conditions belong to a previously unexplored saltation regime. The threshold wind speed required to initiate saltation is only quantitatively predicted by state-of-the art models up to a density ratio between grain and air of 4 × 105 but unexpectedly falls to much lower values for higher density ratios. In contrast, impact ripples, whose emergence is continuously observed on the granular bed over the whole pressure range investigated, display a characteristic wavelength and propagation velocity essentially independent of pressure. A comparison of these findings with existing models suggests that sediment transport at low Reynolds number but high grain-to-fluid density ratio may be dominated by collective effects associated with grain inertia in the granular collisional layer.

AB - Aeolian sediment transport is observed to occur on Mars as well as other extraterrestrial environments, generating ripples and dunes as on Earth. The search for terrestrial analogs of planetary bedforms, as well as environmental simulation experiments able to reproduce their formation in planetary conditions, are powerful ways to question our understanding of geomorphological processes toward unusual environmental conditions. Here, we perform sediment transport laboratory experiments in a closed-circuit wind tunnel placed in a vacuum chamber and operated at extremely low pressures to show that Martian conditions belong to a previously unexplored saltation regime. The threshold wind speed required to initiate saltation is only quantitatively predicted by state-of-the art models up to a density ratio between grain and air of 4 × 105 but unexpectedly falls to much lower values for higher density ratios. In contrast, impact ripples, whose emergence is continuously observed on the granular bed over the whole pressure range investigated, display a characteristic wavelength and propagation velocity essentially independent of pressure. A comparison of these findings with existing models suggests that sediment transport at low Reynolds number but high grain-to-fluid density ratio may be dominated by collective effects associated with grain inertia in the granular collisional layer.

KW - Impact ripples

KW - Mars

KW - Saltation at low pressure

KW - Sediment transport threshold

UR - http://www.scopus.com/inward/record.url?scp=85100067738&partnerID=8YFLogxK

U2 - 10.1073/pnas.2012386118

DO - 10.1073/pnas.2012386118

M3 - Journal article

C2 - 33509927

AN - SCOPUS:85100067738

VL - 118

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 5

M1 - e2012386118

ER -