A model study of corona emission from hydrometeors

SCHROEDER, VICKI; BAKER, MB; Latham, John

doi:10.1256/smsqj.55709

Cited by 9 publications

(13 citation statements)

References 3 publications

(4 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Overall, the results presented here complement the experimental studies mentioned above. The general trend of the decreasing electric field necessary for streamer initiation with increasing hydrometeor length (Figure ) obtained from our study is consistent with the results of these studies, as well as with other previous experimental and theoretical work [e.g., Crabb and Latham , ; Schroeder et al ., ].…”

Section: Discussionmentioning

confidence: 99%

“…They concluded that the emission of positive coronas from colliding raindrops can readily occur in thunderclouds and therefore be a possible source for triggering lightning. Schroeder et al [] conducted a modeling study of positive corona emission around a simulated coalesced water drop. They modeled positive discharges using a one‐dimensional drift‐diffusion equation, paired with an analytical solution to the electric field.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Streamer formation and branching from model hydrometeors in subbreakdown conditions inside thunderclouds

et al. 2015

View full text Add to dashboard Cite

Electric field values measured inside thunderclouds have consistently been reported to be up to an order of magnitude lower than the value required for the conventional electrical breakdown of air. This result has made it difficult to explain how lightning frequently occurs in thunderclouds. A few different theories have been offered to explain the lightning initiation process, one of them being the theory of lightning initiation from hydrometeors. According to this theory, lightning can be initiated from electrical discharges originating around thundercloud water or ice particles in the measured thundercloud electric field. These particles, called hydrometeors, are believed to cause significant enhancement of the thundercloud electric field in their vicinity and then initiate streamers that are the precursor discharges for the hot lightning leader channel. Previously, Liu et al. (2012a) reported streamer formation from a model hydrometeor in an electric field value of half of the conventional breakdown threshold (E k ) for air. In this paper, we present modeling results for streamer formation in electric fields as low as one third of the breakdown threshold. According to our results, initiation of stable streamers from thundercloud hydrometeors in a 0.3E k electric field is possible, only if enhanced ambient ionization levels (e.g., the ionization created by corona discharges around the same or other nearby hydrometeors) are present ahead of the streamer. The magnitude and distribution of this ambient density may be a determining factor on whether the streamer branches, recovers after the prebranching stage, or continues propagating stably. We investigate the streamer branching behavior and characteristics and test a theory that has recently been proposed to explain this phenomenon. We find that the geometry of the streamer head plays an important role in the streamer branching phenomena. The fast radial movement of the maximum streamer head curvature, combined with the slow reduction of the maximum curvature value, eventually leads the streamer head to branching. Finally, we compare our modeling results with laboratory experiments and realistic thundercloud conditions and discuss the implications of this study to lightning initiation and other lightning-related phenomena.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Streamer formation and branching from model hydrometeors in subbreakdown conditions inside thunderclouds

et al. 2015

View full text Add to dashboard Cite

show abstract

“…However, such an electric field intensity is of 1 order of magnitude lower than the electric field threshold required to breakdown cloud air. Therefore, additional ignition mechanisms have been considered, such as runaway electrons (Gurevich et al, 1992) or hydrometeor interactions present in high electric fields (Crabb and Latham, 1974;Coquillat and Chauzy, 1994;Schroeder et al, 1999;Coquillat et al, 2003). Natural lightning flashes then occur when the ambient electric field exceeds a threshold of a few kV m −1 .…”

Section: Introductionmentioning

confidence: 99%

An overview of the lightning and atmospheric electricity observations collected in southern France during the HYdrological cycle in Mediterranean EXperiment (HyMeX), Special Observation Period 1

et al. 2015

View full text Add to dashboard Cite

Abstract. The PEACH project (Projet en Electricité Atmosphérique pour la Campagne HyMeX -the Atmospheric Electricity Project of the HyMeX Program) is the atmospheric electricity component of the Hydrology cycle in the Mediterranean Experiment (HyMeX) experiment and is dedicated to the observation of both lightning activity and electrical state of continental and maritime thunderstorms in the area of the Mediterranean Sea. During the HyMeX SOP1 (Special Observation Period) from 5 September to 6 November 2012, four European operational lightning locating systems (ATDnet, EUCLID, LINET, ZEUS) and the HyMeX lightning mapping array network (HyLMA) were used to locate and characterize the lightning activity over the northwestern Mediterranean at flash, storm and regional scales. Additional research instruments like slow antennas, video cameras, microbarometer and microphone arrays were also operated. All these observations in conjunction with operational/research ground-based and airborne radars, rain gauges and in situ microphysical records are aimed at characterizing and understanding electrically active and highly precipitating events over southeastern France that often lead to severe flash floods. Simulations performed with cloud resolving models like Meso-NH and Weather Research and Forecasting are used to interpret the results and to investigate further the links between dynamics, microphysics, electrification and lightning occurrence. Herein we present an overview of the PEACH project and its different instruments. Examples are discussed to illustrate the comprehensive and Published by Copernicus Publications on behalf of the European Geosciences Union. E. Defer et al.: Atmospheric electricity observations during HyMeX SOP1unique lightning data set, from radio frequency to acoustics, collected during the SOP1 for lightning phenomenology understanding, instrumentation validation, storm characterization and modeling.

show abstract

“…The corona appeared when colliding liquid drops form one long coalesced liquid drop. Schroeder et al () developed a model for corona inception from a long coalesced drop and obtained good agreement with experimental observations. This model was further applied for thunderstorm conditions (Solomon et al, ), and the authors concluded that such mechanism cannot alone trigger lightning.…”

Section: Introductionmentioning

confidence: 79%

Modeling of Streamer Ignition and Propagation in the System of Two Approaching Hydrometeors

Jánský

Pasko

2020

JGR Atmospheres

View full text Add to dashboard Cite

First‐principles plasma fluid modeling is used for investigation of electrical gas discharges ignited by a configuration of two approaching conducting hydrometeors with typical radii on the order of several millimeters under thunderstorm conditions (i.e., at an elevated location in the Earth's atmosphere corresponding to half of air density at ground level and at applied electric field approximately half of that required for avalanche multiplication of electrons in air). It is demonstrated that ultraviolet photons produced by the electrical discharges developing due to the electric field enhancement in the gap between two hydrometeors and resultant photoionization in the discharge volume lead to much less stringent conditions for conversion of these discharges to a filamentary streamer form than in the case not accounting for the effects of photoionization. It is also demonstrated that this photoionization feedback is critical for understanding and correct description of the subsequent streamer discharges developing on the outer periphery of two hydrometeors whose potential is equalized due to the electrical connection established by the initial streamer discharge between them. The initial streamer ignition between the hydrometeors can be preceded by the corona development, which can have detrimental effect on the ignition. However, it is demonstrated that for hydrometeors approaching with a speed of ∼10 m/s the effect of this onset corona is small.

show abstract

A model study of corona emission from hydrometeors

Cited by 9 publications

References 3 publications

Streamer formation and branching from model hydrometeors in subbreakdown conditions inside thunderclouds

Streamer formation and branching from model hydrometeors in subbreakdown conditions inside thunderclouds

An overview of the lightning and atmospheric electricity observations collected in southern France during the HYdrological cycle in Mediterranean EXperiment (HyMeX), Special Observation Period 1

Modeling of Streamer Ignition and Propagation in the System of Two Approaching Hydrometeors

Contact Info

Product

Resources

About