Local enhancement of atmospheric electrical field by long laser spark

The number of explosive eruptions at Shiveluch Volcano has significantly increased over the past years, which requires close volcanic monitoring using all available techniques. In order to implement a new monitoring technique into integrated methods of volcano monitoring, the authors analyze response to the intensity of the vertical component in the atmospheric electrical field (EZ AEF) during the movement of ash clouds. Two eruptions of different intensity that occurred December 16, 2016 and June 14, 2017 at Shiveluch were selected for study. We used a combination of satellite, seismic, and infrasound data to select signals in the EZ AEF field. Signals with negative polarity that accompanied ashfalls in the EZ AEF dynamics were registered for both eruptions within the closest area (< 50 km). In the former case, the ash cloud was “dry” and thus it caused aerial-electrical structure of the negatively charged cloud. In the latter case, a strong explosion sent into the atmosphere the large volume of ash and volcanic gases (98% in form of vapour) that resulted in the formation of a dipolar aerial-electrical structure caused by eolian differentiation within the closest area. At the distance of more than 100 km we registered a positive-going signal that is attributive to the aerial-electrical structure of the positively charged type of the cloud.

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Atmospheric electrical field measurements near a fresh water reservoir and the formation of the lake breeze

Tellus A Dynamic Meteorology and Oceanography ◽

10.3402/tellusa.v68.31592 ◽

2016 ◽

Vol 68 (1) ◽

pp. 31592 ◽

Cited By ~ 10

Author(s):

Francisco Lopes ◽

Hugo Gonçalves Silva ◽

Rui Salgado ◽

Miguel Potes ◽

Keri A. Nicoll ◽

...

Keyword(s):

Fresh Water ◽

Water Reservoir ◽

Field Measurements ◽

Lake Breeze ◽

Electrical Field ◽

Atmospheric Electrical Field

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Atmospheric electrical field decrease during the <i>M = 4.1</i> Sousel earthquake (Portugal)

Natural Hazards and Earth System Science ◽

10.5194/nhess-11-987-2011 ◽

2011 ◽

Vol 11 (3) ◽

pp. 987-991 ◽

Cited By ~ 9

Author(s):

H. G. Silva ◽

M. Bezzeghoud ◽

A. H. Reis ◽

R. N. Rosa ◽

M. Tlemçani ◽

...

Keyword(s):

Vertical Component ◽

Observation Site ◽

Electrical Field ◽

Simple Interpretation ◽

Earthquake Preparation ◽

Atmospheric Electrical Field

Abstract. In this paper, we report the observation of a significant decrease of the vertical component of the atmospheric electrical field in the Évora region (Portugal) during the M = 4.1 Sousel earthquake of 27 March 2010. The epicentre of the earthquake was 52 km from the observation site, which falls within the theoretical earthquake preparation radius. A simple interpretation based on hypothetical radon emissions is presented, and future experiments required to elucidate these observations are outlined. To our knowledge, this is the first reported observation of a decrease of the atmospheric electrical field preceding an earthquake.

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Electric charging of eruptive clouds from Shiveluch Volcano caused by different types of explosions

Вулканология и сейсмология ◽

10.31857/s0205-96142019349-62 ◽

2019 ◽

pp. 49-62

Author(s):

P. P. Firstov ◽

R. R. Akbashev ◽

N. A. Zharinov ◽

A. P. Maximov ◽

T. M. Manevich ◽

...

Keyword(s):

Vertical Component ◽

Shiveluch Volcano ◽

Electrical Field ◽

Electrical Structure ◽

Volcanic Monitoring ◽

Different Types ◽

Integrated Methods ◽

Strong Explosion ◽

Atmospheric Electrical Field ◽

Positively Charged

The number of explosive eruptions at Shiveluch Volcano has significantly increased over the past years, which requires close volcanic monitoring using all available techniques. In order to implement a new monitoring technique into integrated methods of volcano monitoring, the authors analyze response to the intensity of the vertical component in the atmospheric electrical field (EZ AEF) during the movement of ash clouds. Two eruptions of different intensity that occurred December 16, 2016 and June 14, 2017 at Shiveluch were selected for study. We used a combination of satellite, seismic, and infrasound data to select signals in the EZ AEF field. Signals with negative polarity that accompanied ashfalls in the EZ AEF dynamics were registered for both eruptions within the closest area (< 50 km). In the former case, the ash cloud was “dry” and thus it caused aerial-electrical structure of the negatively charged cloud. In the latter case, a strong explosion sent into the atmosphere the large volume of ash and volcanic gases (98% in form of vapour) that resulted in the formation of a dipolar aerial-electrical structure caused by eolian differentiation within the closest area. At the distance of more than 100 km we registered a positive-going signal that is attributive to the aerial-electrical structure of the positively charged type of the cloud.

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Principles of Low-Vacuum SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131152 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1304-1305

Author(s):

Klaus-Ruediger Peters

Keyword(s):

New Technologies ◽

High Vacuum ◽

Optical Microscope ◽

Specimen Surface ◽

Electrical Field ◽

Gaseous Environment ◽

New Information ◽

Gas Molecules ◽

New Interactions ◽

Gas Pressures

Only recently it became possible to expand scanning electron microscopy to low vacuum and atmospheric pressure through the introduction of several new technologies. In principle, only the specimen is provided with a controlled gaseous environment while the optical microscope column is kept at high vacuum. In the specimen chamber, the gas can generate new interactions with i) the probe electrons, ii) the specimen surface, and iii) the specimen-specific signal electrons. The results of these interactions yield new information about specimen surfaces not accessible to conventional high vacuum SEM. Several microscope types are available differing from each other by the maximum available gas pressure and the types of signals which can be used for investigation of specimen properties.Electrical non-conductors can be easily imaged despite charge accumulations at and beneath their surface. At high gas pressures between 10-2 and 2 torr, gas molecules are ionized in the electrical field between the specimen surface and the surrounding microscope parts through signal electrons and, to a certain extent, probe electrons. The gas provides a stable ion flux for a surface charge equalization if sufficient gas ions are provided.

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An ultrastructural analysis of the sympathetic innervation of the rabbit ear artery and middle cerebral artery and their branches

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125075 ◽

1992 ◽

Vol 50 (1) ◽

pp. 934-935

Author(s):

John T. Dodge ◽

John A. Bevan

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Sympathetic Innervation ◽

Electrical Field Stimulation ◽

Rabbit Ear Artery ◽

Electrical Field ◽

Functional Differences ◽

Ear Artery ◽

Rabbit Ear ◽

Vascular Beds

Unlike many peripheral vascular beds, the sympathetic nervous system exerts little control on cerebral blood flow. The contractile response of isolated rabbit middle cerebral artery (MCA) segments to electrical field stimulation of its intramural nerves is less than in a similar-sized artery from the ear. This study was undertaken to characterize and compare the perivascular neuromuscular relationships and innervation density of similar-sized arteries varying in diameter from these two different regional arterial beds to see if there were structural correlates for these functional differences.

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