Filters








622 Hits in 7.7 sec

The physics of wind-blown sand and dust

Jasper F Kok, Eric J R Parteli, Timothy I Michaels, Diana Bou Karam
2012 Reports on progress in physics (Print)  
and the lifting of dust by dust devils and other small-scale vortices.  ...  The transport of sand and dust by wind is a potent erosional force, creates sand dunes and ripples, and loads the atmosphere with suspended dust aerosols.  ...  Acknowledgments The authors would like to thank Orencio Durán, Thomas Pähtz, Oscar Matthews, Yaping Shao, Thomas Gill, Earle Williams, Christopher Hugenholtz, Rob Sullivan and Ralph Lorenz for  ... 
doi:10.1088/0034-4885/75/10/106901 pmid:22982806 fatcat:qnxxnxwsmrhe5igf4vsmc5ui7i

A comprehensive numerical model of wind-blown sand [article]

Jasper F. Kok, Nilton O. Renno
2009 arXiv   pre-print
We aim to use our model to develop a physically-based parameterization of dust emission for use in climate models.  ...  Wind-blown sand, or "saltation", ejects dust aerosols into the atmosphere, creates sand dunes, and erodes geological features.  ...  Acknowledgements We thank Steven Namikas and Keld Rasmussen for insightful discussions, Eugene Farrell for providing us with his compilation of aerodynamic roughness lengths, and Shanna Shaked for comments  ... 
arXiv:0901.0270v1 fatcat:lc6bjuh2ibgxhfsqxaqwyl4lhu

ATLASGAL – Relationship between dense star forming clumps and interstellar masers [article]

S. J. Billington, J. S. Urquhart, C. König, H. Beuther, S. L. Breen, K. M. Menten, J. Campbell-White, S. P. Ellingsen, M. A. Thompson, T. J. T. Moore, D. J. Eden, W. -J. Kim (+1 others)
2020 arXiv   pre-print
We find clump association rates for the water, hydroxyl and methanol masers to be 56, 39 and 82 per cent respectively, within the Galactic longitude range of 60 > l > -60.  ...  Lower limits of the statistical lifetimes for each maser species are derived, ranging from 0.4 - 2 x 10^4 yrs and are in good agreement with the "straw man" evolutionary model previously presented.  ...  We find 549 OH (429 from THOR and 120 from SPLASH), 359 water and 392 12.2 GHz masers sites that are spatially coincident with dust emission (within 3σ ).  ... 
arXiv:2009.14608v1 fatcat:hnxzukflb5autm6aim2wgit72u

Cohesion‐induced enhancement of aeolian saltation

F. Comola, J. Gaume, J. F. Kok, M. Lehning
2019 Geophysical Research Letters  
These findings have implications for dune formation, dust emission, and snow sublimation over cohesive beds.  ...  Although interparticle cohesion is known to limit the number of grains lifted from the surface through aerodynamic entrainment and granular splash, the role of cohesion in the development of saltation  ...  In other words, saltating grains over cohesive beds require several more hop lengths to reach an impact velocity that produces on average one new splashed particle for each grain that fails to rebound.  ... 
doi:10.1029/2019gl082195 fatcat:wfsbzd22hfat7aqgodcdy4wwpy

A comprehensive numerical model of steady state saltation (COMSALT)

Jasper F. Kok, Nilton O. Renno
2009 Journal of Geophysical Research  
COMSALT is the first numerical saltation model to reproduce measurements of the wind shear velocity at the impact threshold (i.e., the lowest shear velocity for which saltation is possible) and of the  ...  1] The blowing of sand by wind, known as saltation, ejects dust aerosols into the atmosphere, creates sand dunes, and erodes geological features.  ...  We thank Steven Namikas and Keld Rasmussen for insightful discussions, Eugene Farrell for providing us with his compilation of aerodynamic roughness lengths, and Shanna Shaked and three anonymous reviewers  ... 
doi:10.1029/2009jd011702 fatcat:y7eq4tr3kzdq5f4sgx4rgnypmq

OUP accepted manuscript

2020 Monthly notices of the Royal Astronomical Society  
The median far-infrared (FIR) mass and luminosity are 630M_ and 2500L_ for sources on the near side of Galactic centre and 3200M_ and 10000L_ for more distant sources.  ...  The median luminosity-to-mass ratio is similar for both at ∼4.2L_/M_.  ...  We would like to thank Andrés Guzmán and Yanett Contreras for their very helpful discussion about the temperature of the maser sources.  ... 
doi:10.1093/mnras/staa233 fatcat:i35jsgbio5eklfwy66ys3r4aq4

An improved dust emission model – Part 1: Model description and comparison against measurements

J. F. Kok, N. M. Mahowald, G. Fratini, J. A. Gillies, M. Ishizuka, J. F. Leys, M. Mikami, M.-S. Park, S.-U. Park, R. S. Van Pelt, T. M. Zobeck
2014 Atmospheric Chemistry and Physics  
</strong> Simulations of the dust cycle and its interactions with the changing Earth system are hindered by the empirical nature of dust emission parameterizations in weather and climate models.  ...  for.  ...  We thank Stéphane Alfaro, Jean Louis Rajot, and Béatrice Marticorena for providing the measurements of Sow et al. (2009) , and for providing comments that helped improve the manuscript.  ... 
doi:10.5194/acp-14-13023-2014 fatcat:mu22oglzxraorhkyrzmoswzvua

An improved dust emission model with insights into the global dust cycle's climate sensitivity

J. F. Kok, N. M. Mahowald, S. Albani, G. Fratini, J. A. Gillies, M. Ishizuka, J. F. Leys, M. Mikami, M.-S. Park, S.-U. Park, R. S. Van Pelt, D. S. Ward (+1 others)
2014 Atmospheric Chemistry and Physics Discussions  
Simulations of the global dust cycle and its interactions with a changing Earth system are hindered by the empirical nature of dust emission parameterizations in climate models.  ...  The resulting dust flux parameterization depends only on the wind friction speed and the soil's threshold friction speed, and can therefore be readily implemented into climate models.  ...  We thank Stéphane Alfaro, Jean Louis Rajot, and Béatrice Marticorena for providing the measurements of Sow et al. (2009), and for providing comments that helped 5 improve the manuscript.  ... 
doi:10.5194/acpd-14-6361-2014 fatcat:sbrctpon45hzzndscefrnis6ka

The physics of wind-blown loess: Implications for grain size proxy interpretations in Quaternary paleoclimate studies

Gábor Újvári, Jasper F. Kok, György Varga, János Kovács
2016 Earth-Science Reviews  
we provide a comprehensive review on the physics of dust particle 27 mobilization and deposition.  ...  efficiency in below-cloud scavenging (for representative raindrop) ε 0 empirical constant in the Zhang et al. (2001) model θ g gravimetric water content (kg kg -1 ) θ g1.5 gravimetric water content at  ...  After a few hops, some of these particles 610 gain sufficient kinetic energy to eject or splash other particles from the soil to the air, with 611 high-energy rebounds forming the saltation population  ... 
doi:10.1016/j.earscirev.2016.01.006 fatcat:glrkcge3lbdg3gxmfvpz7xm2ru

Taxonomy of factors which influence heavy metal build-up on urban road surfaces

An Liu, Chandima Gunawardana, Janaka Gunawardena, Prasanna Egodawatta, Godwin A. Ayoko, Ashantha Goonetilleke
2016 Journal of Hazardous Materials  
This results in limitations in the identification of the most critical factor/s for accurately estimating heavy metal loads and for designing effective stormwater treatment measures.  ...  Heavy metals build-up on urban road surfaces is a complex process and influenced by a diverse range of factors.  ...  This can be also supported by the fact that Cd is a very mobile heavy metal and could be easily transported by runoff, airborne or even splash water [31] .  ... 
doi:10.1016/j.jhazmat.2016.02.026 pmid:26897571 fatcat:343c53ozjncl7gdhxwgsdqhydq

Laboratory studies of aeolian sediment transport processes on planetary surfaces

Keld R. Rasmussen, Alexandre Valance, Jonathan Merrison
2015 Geomorphology  
Abstract We review selected experimental saltation studies performed in laboratory wind tunnels and collision experiments performed in (splash-) laboratory facilities that allow detailed observations between  ...  Acknowledgements We acknowledge Andreas Boes Jakobsen and Jens Jacob Iversen for their help and support with the experimental work in the Aarhus wind tunnel.  ...  We would like to thank Pascal Dupont, Ahmed Ould El Mochtar, and Marc Lämmel for fruitful discussion during the workshop 'Fluid-Mediated  ... 
doi:10.1016/j.geomorph.2015.03.041 fatcat:rcxerlklljdufncg3g3y3yvnau

THE MILAN INTERNATIONAL EXHIBITION

1906 The Lancet  
model of an infirmary with lay figures and aseptic furniture.  ...  Then there are the ventilators, the tubing, and hoods for drawing away the dust.  ... 
doi:10.1016/s0140-6736(01)43838-4 fatcat:ftsn2nciones7ool2ocqrhcxau

Particle Lifting Processes in Dust Devils

L. D. V. Neakrase, M. R. Balme, F. Esposito, T. Kelling, M. Klose, J. F. Kok, B. Marticorena, J. Merrison, M. Patel, G. Wurm
2016 Space Science Reviews  
Mars-analog 24 conditions), and analytical modeling.  ...  effects, and how these processes apply to dust devils on 27 Earth and Mars.  ...  during a single hop than on Earth.  ... 
doi:10.1007/s11214-016-0296-6 fatcat:fgsou6e4dzfr5joxeq5fbrktp4

Practical Solutions for Pesticide Safety: A Farm and Research Team Participatory Model

Kit Galvin, Jen Krenz, Marcy Harrington, Pablo Palmández, Richard A. Fenske
2015 Journal of Agromedicine  
Development of the Practical Solutions for Pesticide Safety guide used participatory research strategies to identify and evaluate solutions that reduce pesticide exposures for workers and their families  ...  Small work groups in a Regional Advisory Committee provided the best direction and guidance for a "user-friendly" translational document that provided evidence-based practical solutions.  ...  We thank the 26 participating farms and the 96 interview participants; Stacey Holland, graphic designer, for providing design elements and the overall look for the guide; Jennifer Crowe for the expert  ... 
doi:10.1080/1059924x.2015.1107519 pmid:26488540 pmcid:PMC5841593 fatcat:o22o6sgvijeerdkd27uij4yfya

The Mars Science Laboratory (MSL) Bagnold Dunes Campaign, Phase I: Overview and introduction to the special issue

Nathan T. Bridges, Bethany L. Ehlmann
2018 Journal of Geophysical Research - Planets  
Also, modeling results show that a few grains making short hops cause a large cascade of grain hops --and thus dune migration --even at very low wind speeds, a characteristic unique to Mars' low gravity  ...  size of sinuous aeolian bedform formed in the high kinetic viscosity regime of Mars' thin atmosphere; articulation and evaluation of a grain splash model that successfully explains the occurrence of saltation  ...  experiments explaining how grain splash can initiate and sustain saltation on Mars even when theoretical threshold wind speeds are Figure A1 .Figure A2 .  ... 
doi:10.1002/2017je005401 fatcat:qedxaksbczaybddpuz4yutpv5q
« Previous Showing results 1 — 15 out of 622 results