Electrification of sand on Titan and its influence on sediment transport

Harper, Joshua Méndez; McDonald, G. D.; Dufek, Josef; Malaska, Michael J.; Burr, D. M.; Hayes, Alexander G.; McAdams, J.; Wray, J. J.

doi:10.1038/ngeo2921

Cited by 46 publications

(38 citation statements)

References 52 publications

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“…The percentage increase in total extinction as a function of charge and particle diameter (1 μm to 1 cm)—that is, ( Q ( c ) − Q )/ Q × 100—appears in Figures a and b for L1 and L2, respectively. This computation was done for the charge density ranges described in section ( η = 10 −8 –10 −5 C/m 2 ; Gilbert et al, ; James et al, ; Méndez Harper & Dufek, ; Méndez Harper et al, ). As demonstrated by Figure , important increases in attenuation (larger than 10 %) occur when the charge density is above η = 10 −7 C/m 2 and the particle size is smaller than 50 μm.…”

Section: Resultsmentioning

confidence: 99%

“…Experimentally, James et al () reported that charge densities on the order of 10 −8 –10 −6.5 C/m 2 were generated during the reduction of pumice samples through either fracture or abrasion. More recently, Méndez Harper et al () reported charge densities ranging between 10 −8 and 10 −6 C/m 2 on Popocatépetl and Atéxcac grains charged frictionally in a controlled experimental environment. We note that most of these experiments used andesitic to rhyolitic compositions.…”

Section: Theory and Methodsmentioning

confidence: 98%

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The Effect of Electrostatic Charge on the Propagation of GPS (L‐band) Signals Through Volcanic Plumes

et al. 2019

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Recent field studies have shown that the presence of ash in the atmosphere can produce measurable attenuation of Global Positioning System (GPS) signals (Aranzulla et al., 2013, https://doi.org/10.1007/s10291-012-0294-4; Larson, 2013, https://doi.org/10.1002/grl.50556; Larson et al., 2017, https://doi.org/10.1016/j.jvolgeores.2017.04.005). The ability to detect plumes using GPS is appealing because many active volcanoes are already instrumented with high‐quality receivers. However, analyses using a Ralyeigh approximation have shown that the large attenuations cannot be explained by the scattering and absorption associated with ash or hydrometeors alone. Here, we show that the extinction of GPS signals, which fall into the L‐band of the electromagnetic spectrum, may be exacerbated significantly by excess surface charge on pyroclasts. Indeed, volcanic eruptions are often accompanied by a range of electrostatic processes, leading, in some cases, to spectacular lightning storms. We use a modified Mie scattering model to demonstrate that electrostatic effects can increase the extinction of L‐band radiation by up to an order of magnitude, producing attenuations consistent with those observed in the field. Thus, future work involving GPS as a tool to remotely probe plumes must take into account the electrification of ash in radiative transfer models. Additionally, we propose that the sensitivity of GPS to particle charging may catalyze the development of new techniques to explore electrostatic processes in plumes, especially if GPS measurements are complemented with millimeter‐wave RADAR measurements.

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Section: Resultsmentioning

confidence: 99%

Section: Theory and Methodsmentioning

confidence: 98%

The Effect of Electrostatic Charge on the Propagation of GPS (L‐band) Signals Through Volcanic Plumes

et al. 2019

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“…It has been recognized that triboelectric charging may be an important effect on Titan (Lorenz 2014;Mendez-Harper et al 2017) as well as Mars, in environments where the lack of surface electrical conductivity via liquid water prevents rapid charge leakage. In the dry high-pressure near-surface atmosphere of Venus, it will be even harder for the charge to leak away from triboelectrically charged sediments.…”

Section: Triboelectric Discharges On Venus Surfacementioning

confidence: 99%

Lightning detection on Venus: a critical review

Lorenz

2018

Prog Earth Planet Sci

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Claimed detections and nondetections of lightning and related electromagnetic emissions on Venus are qualitatively contradictory. Here, motivated by the commencement of observations by the Akatsuki spacecraft and by studies of future missions, we critically review spacecraft and ground-based observations of the past 40 years, in an attempt to reconcile the discordant reports with a minimal number of assumptions. These include invoking alternative interpretations of individual reports, guided by sensitivity thresholds, controls, and other objective benchmarks of observation integrity. The most compelling evidence is in fact the first, the very low frequency (VLF) radio emissions recorded beneath the clouds by all four of the Veneras 11-13 landers, and those data are re-examined closely, finding power-law amplitude characteristics and substantial differences between the different profiles. It is concluded that some kind of frequent electrical activity is supported by the preponderance of observations, but optical emissions are not consistent with terrestrial levels of activity. Venus' activity may, like Earth's, have strong temporal and/or spatial variability, which coupled with the relatively short accumulated observation time for optical measurements, can lead to qualitative discrepancies between observation reports. We note a number of previously unconsidered observations and outline some considerations for future observations.

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“…Thus, volcanic lightning may provide a valuable monitoring tool for active volcanoes, allowing detection of ash emissions from safe distance and in inclement weather conditions [Behnke and McNutt, 2014]. However, the use of volcanic lightning to probe the properties of volcanic plumes (ash concentration, mass eruption rate, turbulence, etc) has been hampered so far largely by (i) the lack of systematic instrumental observation of electric activity in volcanic plumes and (ii) the limited number of experimental investigations on the electrification processes of volcanic materials [James et al, 2000;Houghton et al, 2013;Méndez-Harper et al, 2015] and the mechanism of plume electrification [Cimarelli et al, 2014].…”

Section: Introductionmentioning

confidence: 99%

Multiparametric observation of volcanic lightning: Sakurajima Volcano, Japan

Cimarelli

Alatorre‐Ibargüengoitia

Aizawa

et al. 2016

Geophysical Research Letters

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We recorded volcanic lightning generated by Vulcanian explosions at Sakurajima Volcano using a synchronized multiparametric array. Physical properties of lightning are related to plume dynamics, and associated electromagnetic field variations are revealed by video observations (high speed and normal speed) together with infrasound and high sampling rate magnetotelluric signals. Data show that volcanic lightning at Sakurajima mainly occurs in the plume gas thrust region at a few hundred meters above the crater rim, where the overpressure of the turbulent volcanic jets determines the electrification of particles generating a complex charge structure in the growing plume. Organization of charges may be achieved at later stages when the plume transitions from the jet phase to the convective phase. Comparison with atmospheric sounding and maximum plume height data show that the effect of hydrometeors on flash generation at Sakurajima is negligible and can be more prudently considered as an additional factor contributing to the electrification of volcanic plumes.

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Electrification of sand on Titan and its influence on sediment transport

Cited by 46 publications

References 52 publications

The Effect of Electrostatic Charge on the Propagation of GPS (L‐band) Signals Through Volcanic Plumes

The Effect of Electrostatic Charge on the Propagation of GPS (L‐band) Signals Through Volcanic Plumes

Lightning detection on Venus: a critical review

Multiparametric observation of volcanic lightning: Sakurajima Volcano, Japan

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