Characterization of ions at Alpine waterfalls

Kolarž, P.; Gaisberger, Martin; Madl, Pierre; Hofmann, Werner; Ritter, Markus; Hartl, Arnulf

doi:10.5194/acp-12-3687-2012

Cited by 46 publications

(45 citation statements)

References 39 publications

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“…In contrast to our observations during rainfall, their observations showed a continuous increase but no significant maxima at higher particle sizes. In another study near five different waterfalls in Austrian Alps, waterfall-generated ions were found to have peaks at 1.5-2.0 nm and 120 nm [Kolarz et al, 2012]. Moreover, concentrations of ions of < 0.6 nm were observed to increase with decrease in their size.…”

Section: Journal Of Geophysical Research: Atmospheresmentioning

confidence: 95%

“…From the results of their measurements, they concluded that the bursts of intermediate ions produced during splashing of raindrops cannot be considered as the nucleation bursts. In a 3 year field campaign in Austrian Alps, Kolarz et al [2012] detected high negative ion concentration gradients with only moderate increase in positive ions in the vicinity of waterfalls. Blanchard [1955Blanchard [ , 1966, Gathman and Trent [1968], Gathman and Hoppel [1970], and Reiter [1994] have studied the formation of charged droplets resulting from the busting of bubbles on the water surface and sea spray.…”

Section: Introductionmentioning

confidence: 99%

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Charged nanoparticles produced by splashing of raindrops

2015

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The mobility distribution of ions generated by splashing of raindrops is investigated. Our observations show four maxima in the mobility distribution in the small, intermediate, light large, and heavy large ion size ranges. Ion concentration of all categories increases as the rain intensity increases tõ 50-60 mm h À1 and then tends to level off for higher rain intensities. Negative ion concentration is always more than that of positive ions. However, positive small ions of mobility ≥ 2-3 cm 2 V À1 s À1 which are also generated during splashing are more numerous than negative ions. Our observations show that the mechanism responsible for the generation of intermediate ions is more efficient than that for the generation of heavy large ions during periods of high rain intensity. Relative roles of Lenard and Blanchard effects are suggested in generating excess of negative intermediate ions in the initial stages and excess of positive cluster ions, in the later stages of a rain shower, respectively.

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Section: Journal Of Geophysical Research: Atmospheresmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Charged nanoparticles produced by splashing of raindrops

2015

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“…The waterfall effect 26 Lenard (1892) reported that the air near the base of a waterfall was negatively charged; subsequent 27 laboratory experiments indicated that breakup of the water stream is required; a jet of water did not 28 lead to charge separation (Lenard, 1915). The phenomenon now known as Lenard,waterfall,29 balloelectric or spray electrification is well established, having been confirmed at various times and 30 places (Natanson,1950) (Pierce,1965) (Reiter, 1994) (Laakso, 2007) (Kolarz, 2012). Recent work has 31…”

mentioning

confidence: 91%

“…shown that the numbers of both negatively and positively charged small clusters of water molecules less 32 than 30 nm in diameter are increased but that the negatively charged 'air ions' are at least ten times 33 more numerous than the positive ones (Kolarz, 2012). spray.…”

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confidence: 99%

The mechanism of spray electrification: the waterfall effect

Beattie

2016

Preprint

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The waterfall effect describes the separation of charge by splashing at the base of a waterfall. Smaller drops that have a net negative charge are created, while larger drops and/or the bulk maintain overall charge neutrality with a net positive charge. Since it was first described by Lenard (1892) the effect has been confirmed many times, but a molecular explanation has not been available. Application of our fluctuation-correlation model of hydrophobic hydration accounts for the negative charge observed at aqueous interfaces with low permittivity materials. The negative surface charge observed in the waterfall effect is created by the preferential adsorption of hydroxide ions generated from the autolysis of water. On splashing, shear forces generate small negative drops from the surface, leaving a positive charge on the remaining large fragment. The waterfall effect is a manifestation of the general phenomenon of the negative charge at the interface between water and hydrophobic surfaces that is created by the preferential adsorption of hydroxide ions.

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“…For example, special ionizers were tested that employ the stimulation of plants placed in a salt solution with high electric voltage [20], and their influence and effect on the tracheas of laboratory (sewer-) rats were evaluated, together with an analysis of the state of their blood. Measuring the concentration of air ions is widely applied in monitoring the degree of air pollution, hygiene checks at workplaces, health therapy -speleotherapy [21]- [23], in the study of electric phenomena in the atmosphere and, topically, in forecasting earthquakes [24], [25] or other weather anomalies. Aplin [26] describes the effects of atmospheric electricity on its surroundings and the manner it is generated in the troposphere.…”

Section: Introductionmentioning

confidence: 99%

Measuring Light Air Ions in a Speleotherapeutic Cave

Roubal

Bartušek

Szabó

et al. 2017

Measurement Science Review

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The paper deals with a methodology proposed for measuring the concentration of air ions in the environment of speleotherapeutic caves, and with the implementation of the AK-UTEE-v2 ionmeter. Speleotherapy, in the context of its general definition, is the medical therapy that utilizes the climate of selected caves to treat patients with health problems such as asthma. These spaces are characterized by the presence of high air humidity and they make extreme demands on the execution of the measuring device, the Gerdien tube (GT in the following) in particular, and on the amplifier electronics. The result is an automated measuring system using a GT with low-volume air flow, enabling long-term measuring of air ion concentration and determination of spectral ion characteristics. Interesting from the instrumentation viewpoint are the GT design, active shielding, and execution of the electrometric amplifier. A specific method for the calculation of spectral ion characteristics and the mode of automatic calibration were proposed and a procedure of automatic measurement in the absence of attendants was set up. The measuring system is designed for studying and long-term monitoring of the concentration of light negative ions in dependence on climatic conditions and on the mobility of ions occurring in the cave.

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Characterization of ions at Alpine waterfalls

Cited by 46 publications

References 39 publications

Charged nanoparticles produced by splashing of raindrops

Charged nanoparticles produced by splashing of raindrops

The mechanism of spray electrification: the waterfall effect

Measuring Light Air Ions in a Speleotherapeutic Cave

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