Vortex Encounter Rates with Fixed Barometer Stations: Comparison with Visual Dust Devil Counts and Large-Eddy Simulations

Abstract A phenomenological model is developed wherein vortices are introduced at random into a virtual arena with specified distributions of diameter, core pressure drop, longevity, and translation speed, and the pressure history at a fixed station is generated using an analytic model of vortex structure. Only a subset of the vortices present are detected as temporary pressure drops, and the observed peak pressure-drop distribution has a shallower slope than the vortex-core pressure drops. Field studies indicate a detection rate of about two vortex events per day under favorable conditions for a threshold of 0.2 mb (1 mb = 1 hPa): this encounter rate and the observed falloff of events with increasing pressure drop can be reproduced in the model with approximately 300 vortices per square kilometer per day—rather more than the highest visual dust devil counts of approximately 100 devils per square kilometer per day. This difference can be reconciled if dust lifting typically only occurs in the field above a threshold core pressure drop of about 0.3 mb, consistent with observed laboratory pressure thresholds. The vortex population modeled to reproduce field results is concordant with recent high-resolution large-eddy simulations, which produce some thousands of 0.04–0.1-mb vortices per square kilometer per day, suggesting that these accurately reproduce the character of the strongly heated desert boundary layer. The amplitude and duration statistics of observed pressure drops suggest large dust devils may preferentially be associated with low winds.

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Comment on ''Observing desert dust devils with a pressure logger" by Lorenz (2012) – insights on measured pressure fluctuations from large-eddy simulations

Geoscientific Instrumentation Methods and Data Systems ◽

10.5194/gi-1-151-2012 ◽

2012 ◽

Vol 1 (2) ◽

pp. 151-154 ◽

Cited By ~ 5

Author(s):

A. Spiga

Keyword(s):

Pressure Fluctuations ◽

Field Measurements ◽

Large Eddy Simulations ◽

Pressure Measurements ◽

Dust Devils ◽

Pressure Drops ◽

Large Eddy ◽

Measured Pressure ◽

Term Field

Abstract. Lorenz et al. (2012) proposes to use pressure loggers for long-term field measurements in terrestrial deserts. The dataset obtained through this method features both pressure drops (reminiscent of dust devils) and periodic convective signatures. Here we use large-eddy simulations to provide an explanation for those periodic convective signatures and to argue that pressure measurements in deserts have broader applications than monitoring dust devils.

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Comment on "Observing desert dust devils with a pressure logger" by Lorenz (2012)

Geoscientific Instrumentation Methods and Data Systems Discussions ◽

10.5194/gid-2-593-2012 ◽

2012 ◽

Vol 2 (2) ◽

pp. 593-601 ◽

Cited By ~ 4

Author(s):

A. Spiga

Keyword(s):

Field Measurements ◽

Large Eddy Simulations ◽

Pressure Measurements ◽

Dust Devils ◽

Pressure Drops ◽

Desert Dust ◽

Large Eddy ◽

Term Field

Abstract. Lorenz (2012) proposes to use pressure loggers for long-term field measurements in terrestrial deserts. The dataset obtained through this method features both pressure drops (reminiscent of dust devils) and periodic convective signatures. Here we use Large-Eddy Simulations to provide an explanation for those periodic convective signatures and to argue that pressure measurements in deserts have broader applications than monitoring dust devils.

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Daytime and nighttime turbulence on Mars monitored by InSight

10.5194/egusphere-egu2020-21327 ◽

2020 ◽

Author(s):

Aymeric Spiga ◽

Naomi Murdoch ◽

Don Banfield ◽

Ralph Lorenz ◽

Claire Newman ◽

...

Keyword(s):

Gravity Waves ◽

High Frequency ◽

Seismic Signal ◽

Atmospheric Science ◽

Large Eddy Simulations ◽

Dust Devil ◽

Large Eddy ◽

The Many ◽

Convective Vortices

<p>The InSight instrumentation for atmospheric science combines high frequency, high accuracy and continuity. This makes InSight a mission particularly suitable for studies of the variability in the Planetary Boundary Layer (PBL) of Mars -- all the more since this topic is of direct interest for quake detectability given that turbulence is the main contributor to atmosphere-induced seismic signal. For the strong daytime buoyancy-driven PBL convection, InSight significantly extends the statistics of dust-devil-like convective vortices and turbulent wind gustiness, both of which are of strong interest for aeolian science. For the moderate nighttime shear-induced PBL convection, InSight enables to explore phenomena and variability left unexplored by previous in-situ measurements on Mars. In both daytime and nighttime environments, how the gravity waves and infrasound signals discovered by InSight are being guided within the PBL is also a central topic to InSight's atmospheric investigations, with the tantalizing possibility to identify possible sources for those phenomena. InSight has been operating at the surface of Mars since 18 months, thus the seasonal evolution of the many phenomena occurring in the PBL will be an emphasis of this report. Comparisons with turbulence-resolving modeling such as Large-Eddy Simulations will be also discussed.</p>

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Observing desert dust devils with a pressure logger

Geoscientific Instrumentation Methods and Data Systems Discussions ◽

10.5194/gid-2-477-2012 ◽

2012 ◽

Vol 2 (2) ◽

pp. 477-505 ◽

Cited By ~ 7

Author(s):

R. D. Lorenz

Keyword(s):

Flash Memory ◽

Large Data ◽

Dust Devil ◽

Dust Devils ◽

Temperature Drift ◽

Pressure Drops ◽

Array Measurements ◽

Solar Battery ◽

Data Volume

Abstract. A commercial pressure logger has been adapted for long-term field use. Its flash memory affords the large data volume to allow months of pressure measurements to be acquired at the rapid cadence (>1 Hz) required to detect dust devils, small dust-laden convective vortices observed in arid regions. The power consumption of the unit is studied and battery and solar/battery options evaluated for long-term observations. A two-month-long field test is described, and several example dust devil encounters are examined. In addition, a periodic (~20 min) convective signature is observed, and some lessons in operations and correction of data for temperature drift are reported. The unit shows promise for obtaining good statistics on dust devil pressure drops, to permit comparison with Mars lander measurements, and for array measurements.

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Large-Eddy Simulations of Dust Devils and Convective Vortices

Space Science Reviews ◽

10.1007/s11214-016-0284-x ◽

2016 ◽

Vol 203 (1-4) ◽

pp. 245-275 ◽

Cited By ~ 13

Author(s):

Aymeric Spiga ◽

Erika Barth ◽

Zhaolin Gu ◽

Fabian Hoffmann ◽

Junshi Ito ◽

...

Keyword(s):

Large Eddy Simulations ◽

Dust Devils ◽

Large Eddy ◽

Convective Vortices

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Observing desert dust devils with a pressure logger

Geoscientific Instrumentation Methods and Data Systems ◽

10.5194/gi-1-209-2012 ◽

2012 ◽

Vol 1 (2) ◽

pp. 209-220 ◽

Cited By ~ 14

Author(s):

R. D. Lorenz

Keyword(s):

Flash Memory ◽

Large Data ◽

Dust Devil ◽

Dust Devils ◽

Temperature Drift ◽

Pressure Drops ◽

Array Measurements ◽

Solar Battery ◽

Data Volume

Abstract. A commercial pressure logger has been adapted for long-term field use. Its flash memory affords the large data volume to allow months of pressure measurements to be acquired at the rapid cadence (>1 Hz) required to detect dust devils, small dust-laden convective vortices observed in arid regions. The power consumption of the unit is studied and battery and solar/battery options evaluated for long-term observations. A two-month long field test is described, and several example dust devil encounters are examined. In addition, a periodic (~20 min) convective signature is observed, and some lessons in operations and correction of data for temperature drift are reported. The unit shows promise for obtaining good statistics on dust devil pressure drops, to permit comparison with Mars lander measurements, and for array measurements.

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Numerical Simulation of Dust Lifting within Dust Devils—Simulation of an Intense Vortex

Journal of the Atmospheric Sciences ◽

10.1175/jas3748.1 ◽

2006 ◽

Vol 63 (10) ◽

pp. 2630-2641 ◽

Cited By ~ 32

Author(s):

Zhaolin Gu ◽

Yongzhi Zhao ◽

Yun Li ◽

Yongzhang Yu ◽

Xiao Feng

Keyword(s):

Ground Surface ◽

Solid Particles ◽

Dust Particles ◽

Mature Stage ◽

Dust Devil ◽

Dust Grains ◽

Dust Devils ◽

Atmospheric Flow ◽

Dust Lifting ◽

The Impact

Abstract Based on an advanced dust devil–scale large-eddy simulation (LES) model, the atmosphere flow of a modeled dust devil in a quasi–steady state was first simulated to illustrate the characteristics of the gas phase field in the mature stage, including the prediction of the lower pressure and higher temperature in the vortex core. The dust-lifting physics is examined in two aspects. Through the experimental data analysis, it is verified again that the horizontal swirling wind can only make solid particles saltate along the ground surface. Based on a Lagrangian reference frame, the tracks of dust grains with different density (material) and diameter are calculated to show the effect of dust particles entrained by the vertical swirling wind field. The movement of solid particles depends on the interactions between the aloft dust particles and the airflow field of dust devils, in which the drag and the centrifugal force component on the horizontal plane are the key force components. There is the trend of the fine dust grains rising along the inner helical tracks while the large dust grains are lifting along the outer helical tracks and then descending beyond the corner region, resulting in the impact between different-sized dust grains in the swirling atmospheric flow. This trend will make the dust stratification, developing a top small-sized grain domain and a bottom large-sized grain domain in dust devils.

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