Radar and Lightning Observations of the 3 June 2000 Electrically Inverted Storm from STEPS

Abstract This study addresses the kinematic, microphysical, and electrical evolution of an isolated convective storm observed on 3 June 2000 during the Severe Thunderstorm Electrification and Precipitation Study field campaign. Doppler-derived vertical velocities, radar reflectivity, hydrometeor classifications from polarimetric radar, and Lightning Mapping Array (LMA) charge structures are examined over a nearly 3-h period. This storm, characterized as a low-precipitation supercell, produced modest amounts of hail, determined by fuzzy-logic hydrometeor classification as mostly small (<2 cm) hail, with one surface report of large (≥2 cm) hail. Doppler-derived updraft speeds peaked between 20 and 25 m s−1, and reflectivity was never greater than 60 dBZ. The most striking feature of this storm was its total lack of cloud-to-ground (CG) lightning. Though this storm was electrically active, with maximum flash rates near 30 per minute, no CG flashes of either polarity were detected. The charge structure inferred from the LMA observations was consistent with an inverted dipole, defined as having a midlevel positive charge region below upper-level negative charge. Inverted charge structures have typically been considered conducive to producing positive CG lightning; however, the 3 June storm appeared to lack the lower negative charge layer below the inverted dipole that is thought to provide the downward electrical bias necessary for positive CG lightning.

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Evolving Complex Electrical Structures of the STEPS 25 June 2000 Multicell Storm

Monthly Weather Review ◽

10.1175/2007mwr2023.1 ◽

2008 ◽

Vol 136 (2) ◽

pp. 741-756 ◽

Cited By ~ 38

Author(s):

Stephanie A. Weiss ◽

W. David Rust ◽

Donald R. MacGorman ◽

Eric C. Bruning ◽

Paul R. Krehbiel

Keyword(s):

Great Plains ◽

Negative Charge ◽

Positive Charge ◽

Three Dimensional ◽

Lightning Flash ◽

Severe Thunderstorm ◽

Electrical Structure ◽

High Reflectivity ◽

Maximum Value ◽

Mapping Array

Abstract Data from a three-dimensional lightning mapping array (LMA) and from two soundings by balloon-borne electric field meters (EFMs) were used to analyze the electrical structures of a multicell storm observed on 25 June 2000 during the Severe Thunderstorm Electrification and Precipitation Study (STEPS). This storm had a complex, multicell structure with four sections, each of whose electrical structure differed from that of the others during all or part of the analyzed period. The number of vertically stacked charge regions in any given section of the storm ranged from two to six. The most complex charge and lightning structures occurred in regions with the highest reflectivity values and the deepest reflectivity cores. Intracloud flashes tended to concentrate in areas with large radar reflectivity values, though some propagated across more than one core of high reflectivity or into the low-reflectivity anvil. Intracloud lightning flash rates decreased as the vertical extent and maximum value of reflectivity cores decreased. Cloud-to-ground flash rates increased as cores of high reflectivity descended to low altitudes. Most cloud-to-ground flashes were positive. All observed positive ground flashes initiated between the lowest-altitude negative charge region and a positive charge region just above it. The storm’s complexity makes it hard to classify the vertical polarity of its overall charge structure, but most of the storm had a different vertical polarity than what is typically observed outside the Great Plains. The electrical structure can vary considerably from storm to storm, or even within the same storm, as in the present case.

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Electrical and Polarimetric Radar Observations of a Multicell Storm in TELEX

Monthly Weather Review ◽

10.1175/mwr3421.1 ◽

2007 ◽

Vol 135 (7) ◽

pp. 2525-2544 ◽

Cited By ~ 73

Author(s):

Eric C. Bruning ◽

W. David Rust ◽

Terry J. Schuur ◽

Donald R. MacGorman ◽

Paul R. Krehbiel ◽

...

Keyword(s):

Electric Field ◽

Electric Fields ◽

Negative Charge ◽

Positive Charge ◽

Three Dimensional ◽

Phase Region ◽

Polarimetric Radar ◽

Radar Observations ◽

Mapping Array ◽

Lightning Initiation

Abstract On 28–29 June 2004 a multicellular thunderstorm west of Oklahoma City, Oklahoma, was probed as part of the Thunderstorm Electrification and Lightning Experiment field program. This study makes use of radar observations from the Norman, Oklahoma, polarimetric Weather Surveillance Radar-1988 Doppler, three-dimensional lightning mapping data from the Oklahoma Lightning Mapping Array (LMA), and balloon-borne vector electric field meter (EFM) measurements. The storm had a low flash rate (30 flashes in 40 min). Four charge regions were inferred from a combination of LMA and EFM data. Lower positive charge near 4 km and midlevel negative charge from 4.5 to 6 km MSL (from 0° to −6.5°C) were generated in and adjacent to a vigorous updraft pulse. Further midlevel negative charge from 4.5 to 6 km MSL and upper positive charge from 6 to 8 km (from −6.5° to −19°C) were generated later in quantity sufficient to initiate lightning as the updraft decayed. A negative screening layer was present near the storm top (8.5 km MSL, −25°C). Initial lightning flashes were between lower positive and midlevel negative charge and started occurring shortly after a cell began lofting hydrometeors into the mixed phase region, where graupel was formed. A leader from the storm’s first flash avoided a region where polarimetric radar suggested wet growth and the resultant absence of noninductive charging of those hydrometeors. Initiation locations of later flashes that propagated into the upper positive charge tracked the descending location of a polarimetric signature of graupel. As the storm decayed, electric fields greater than 160 kV m−1 exceeded the minimum threshold for lightning initiation suggested by the hypothesized runaway breakdown process at 5.5 km MSL, but lightning did not occur. The small spatial extent (≈100 m) of the large electric field may not have been sufficient to allow runaway breakdown to fully develop and initiate lightning.

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The 29 June 2000 Supercell Observed during STEPS. Part II: Lightning and Charge Structure

Journal of the Atmospheric Sciences ◽

10.1175/jas3615.1 ◽

2005 ◽

Vol 62 (12) ◽

pp. 4151-4177 ◽

Cited By ~ 233

Author(s):

Kyle C. Wiens ◽

Steven A. Rutledge ◽

Sarah A. Tessendorf

Keyword(s):

Positive Charge ◽

Lightning Activity ◽

Structure Evolution ◽

Severe Thunderstorm ◽

Charge Structure ◽

Flash Rate ◽

Lightning Detection ◽

Mapping Array ◽

Total Lightning ◽

Mexico Tech

Abstract This second part of a two-part study examines the lightning and charge structure evolution of the 29 June 2000 tornadic supercell observed during the Severe Thunderstorm Electrification and Precipitation Study (STEPS). Data from the National Lightning Detection Network and the New Mexico Tech Lightning Mapping Array (LMA) are used to quantify the total and cloud-to-ground (CG) flash rates. Additionally, the LMA data are used to infer gross charge structure and to determine the origin locations and charge regions involved in the CG flashes. The total flash rate reached nearly 300 min−1 and was well correlated with radar-inferred updraft and graupel echo volumes. Intracloud flashes accounted for 95%–100% of the total lightning activity during any given minute. Nearly 90% of the CG flashes delivered a positive charge to ground (+CGs). The charge structure during the first 20 min of this storm consisted of a midlevel negative charge overlying lower positive charge with no evidence of an upper positive charge. The charge structure in the later (severe) phase was more complex but maintained what could be roughly described as an inverted tripole, dominated by a deep midlevel (5–9 km MSL) region of positive charge. The storm produced only two CG flashes (both positive) in the first 2 h of lightning activity, both of which occurred during a brief surge in updraft and hail production. Frequent +CG flashes began nearly coincident with dramatic increases in storm updraft, hail production, total flash rate, and the formation of an F1 tornado. The +CG flashes tended to cluster in or just downwind of the heaviest precipitation, which usually contained hail. The +CG flashes all originated between 5 and 9 km MSL, centered at 6.8 km (−10°C), and tapped LMA-inferred positive charge both in the precipitation core and (more often) in weaker reflectivity extending downwind. All but one of the −CG flashes originated from >9 km MSL and tended to strike near the precipitation core.

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Radar and Lightning Observations of Normal and Inverted Polarity Multicellular Storms from STEPS

Monthly Weather Review ◽

10.1175/2007mwr1954.1 ◽

2007 ◽

Vol 135 (11) ◽

pp. 3682-3706 ◽

Cited By ~ 63

Author(s):

Sarah A. Tessendorf ◽

Steven A. Rutledge ◽

Kyle C. Wiens

Keyword(s):

Los Alamos ◽

Severe Thunderstorm ◽

Charge Structure ◽

Array Data ◽

Lightning Detection ◽

Normal Polarity ◽

Mapping Array ◽

Intracloud Discharges ◽

Cg Lightning

Abstract This study discusses radar and lightning observations of two multicellular storms observed during the Severe Thunderstorm Electrification and Precipitation Study. The Lightning Mapping Array data indicated that the charge structure of the 19 June 2000 storm was consistent with a normal polarity tripole, while the 22 June 2000 storm exhibited an overall inverted tripolar charge structure. The 19 June storm consisted of weaker convection and produced little to no hail and moderate total flash rates peaking between 80 and 120 min−1. The cells in the 22 June 2000 storm were much more vigorous, exhibited strong, broad updrafts, and produced large quantities of hail, as well as extraordinary total flash rates as high as 500 min−1. The National Lightning Detection Network (NLDN) indicated that the 19 June storm produced mostly negative cloud-to-ground (CG) lightning, while the 22 June storm produced predominantly positive CG lightning, peaking at 10 min−1 just after two cells merged. However, the Los Alamos Sferic Array indicated that many of the positive CG strokes reported by the NLDN in the 22 June storm were intracloud discharges known as narrow bipolar events. Negative CG lightning was also observed in the 22 June storm, but typically came to ground beneath an inverted dipole in the storm anvil.

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Lightning Activity in a Hail-Producing Storm Observed with Phased-Array Radar

Monthly Weather Review ◽

10.1175/2010mwr3574.1 ◽

2011 ◽

Vol 139 (6) ◽

pp. 1809-1825 ◽

Cited By ~ 52

Author(s):

C. Emersic ◽

P. L. Heinselman ◽

D. R. MacGorman ◽

E. C. Bruning

Keyword(s):

Phased Array ◽

Velocity Structure ◽

Negative Charge ◽

Positive Charge ◽

Lightning Activity ◽

Mature Stage ◽

Charge Structure ◽

Phased Array Radar ◽

Lightning Detection ◽

Mapping Array

Abstract This study examined lightning activity relative to the rapidly evolving kinematics of a hail-producing storm on 15 August 2006. Data were provided by the National Weather Radar Testbed Phased-Array Radar, the Oklahoma Lightning Mapping Array, and the National Lightning Detection Network. This analysis is the first to compare the electrical characteristics of a hail-producing storm with the reflectivity and radial velocity structure at temporal resolutions of less than 1 min. Total flash rates increased to approximately 220 min−1 as the storm’s updraft first intensified, leveled off during its first mature stage, and then decreased for 2–3 min despite the simultaneous development of another updraft surge. This reduction in flash rate occurred as wet hail formed in the new updraft and was likely related to the wet growth; wet growth is not conducive to hydrometeor charging and probably contributed to the formation of a “lightning hole” without a mesocyclone. Total flash rates subsequently increased to approximately 450 min−1 as storm volume and inferred graupel volume increased, and then decreased as the storm dissipated. The vertical charge structure in the storm initially formed a positive tripole (midlevel negative charge between upper and lower positive charges). The charge structure in the second updraft surge consisted of a negative charge above a deep midlevel positive charge, a reversal consistent with the effects of large liquid water contents on hydrometeor charge polarity in laboratory experiments. Prior to the second updraft surge, the storm produced two cloud-to-ground flashes, both lowering the usual negative charge to ground. Shortly before hail likely reached ground, the storm produced four cloud-to-ground flashes, all lowering the positive charge. Episodes of high singlet VHF sources were observed at approximately 13–15 km during the initial formation and later intensification of the storm’s updraft.

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Zerumbone Inhibits Helicobacter pylori Urease Activity

Molecules ◽

10.3390/molecules26092663 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2663

Author(s):

Hyun Jun Woo ◽

Ji Yeong Yang ◽

Pyeongjae Lee ◽

Jong-Bae Kim ◽

Sa-Hyun Kim

Keyword(s):

Helicobacter Pylori ◽

Carbon Atom ◽

Natural Compound ◽

Urease Activity ◽

Negative Charge ◽

Positive Charge ◽

Gastric Epithelium ◽

Functional Inhibition ◽

Electrical Gradient ◽

H Pylori

Helicobacter pylori (H. pylori) produces urease in order to improve its settlement and growth in the human gastric epithelium. Urease inhibitors likely represent potentially powerful therapeutics for treating H. pylori; however, their instability and toxicity have proven problematic in human clinical trials. In this study, we investigate the ability of a natural compound extracted from Zingiber zerumbet Smith, zerumbone, to inhibit the urease activity of H. pylori by formation of urease dimers, trimers, or tetramers. As an oxygen atom possesses stronger electronegativity than the first carbon atom bonded to it, in the zerumbone structure, the neighboring second carbon atom shows a relatively negative charge (δ−) and the next carbon atom shows a positive charge (δ+), sequentially. Due to this electrical gradient, it is possible that H. pylori urease with its negative charges (such as thiol radicals) might bind to the β-position carbon of zerumbone. Our results show that zerumbone dimerized, trimerized, or tetramerized with both H. pylori urease A and urease B molecules, and that this formation of complex inhibited H. pylori urease activity. Although zerumbone did not affect either gene transcription or the protein expression of urease A and urease B, our study demonstrated that zerumbone could effectively dimerize with both urease molecules and caused significant functional inhibition of urease activity. In short, our findings suggest that zerumbone may be an effective H. pylori urease inhibitor that may be suitable for therapeutic use in humans.

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Indication of the Coronavirus Model Using a Nanowire Biosensor

Proceedings ◽

10.3390/iecb2020-07228 ◽

2020 ◽

Vol 60 (1) ◽

pp. 50

Author(s):

Vladimir Generalov ◽

Olga Naumova ◽

Dmitry Shcherbakov ◽

Alexander Safatov ◽

Boris Zaitsev ◽

...

Keyword(s):

Field Effect ◽

Field Effect Transistor ◽

Negative Charge ◽

Positive Charge ◽

Silicon On Insulator ◽

Nanowire Surface ◽

Before And After ◽

Effect Transistor ◽

Current Value ◽

Silicon On Insulator Technology

The presented results indicate virus-like particles of the coronavirus (CVP) using a nanowire (NW) biosensor based on silicon-on-insulator technology. In the experiment, we used suspensions of CVP and of specific antibodies to the virus. Measurements of the current value of the field-effect transistor before and after the introduction of the CVP on the surface of the nanowire were performed. Results showed antibody + CVP complexes on the phase section with the surface of the nanowire modulate the current of the field-effect transistor; CVP has an electrically positive charge on the phase section “nanowire surface-viral suspension»; antibody + CVP complexes have an electrically negative charge on the phase section “nanowire surface-viral suspension”; the sensitivity of the biosensor is made up of 10−18 M; the time display was 200–300 s.

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The mechanism of spray electrification: the waterfall effect

10.5194/acp-2015-892 ◽

2016 ◽

Cited By ~ 1

Author(s):

James K. Beattie

Keyword(s):

Negative Charge ◽

Positive Charge ◽

Hydrophobic Hydration ◽

General Phenomenon ◽

Aqueous Interfaces ◽

Preferential Adsorption ◽

Negative Surface ◽

Negative Surface Charge ◽

Low Permittivity ◽

Net Positive Charge

Abstract. 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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THE EFFECT OF PROCOAGULANT PHOSPHOLIPID VESICLES WITH NET POSITIVE CHARGE ON THE ACTIVITY OF PROTHROMBINASE

10.1055/s-0038-1643839 ◽

1987 ◽

Author(s):

J Rosing ◽

H Speijer ◽

J W P Govers-Riemslag ◽

R F A Zwaal

Keyword(s):

Vitamin K ◽

Negative Charge ◽

Positive Charge ◽

Coagulation Factor ◽

Phospholipid Vesicles ◽

Electrostatic Model ◽

Acidic Phospholipid ◽

Positively Charged ◽

Net Positive Charge ◽

Prothrombin Activation

It is generally thought that procoagulant phospholipid surfaces that promote the activation of vitamin K-dependent coagulation factors should have a net negative charge in order to promote calcium-dependent binding of the enzymes (FVIIa, FIXa and FXa) and substrates (prothrombin and FX) of the coagulation factor-activating complexes. Two models have been proposed to explain calcium-mediated association of vitamin K-dependent proteins with phospholipid: a) an electrostatic model, in which a positively-charged protein-calcium complex is attracted by a negatively-charged phospholipid surface and b) a chelation model in which a coordination complex is formed between calcium ions, γ-carboxyglutamic acids of the proteins and negatively-charged membrane phospholipids. To study the effect of the electrostatic potential of phospholipid vesicles on their activity in the pro-thrombinase complex the net charge of vesicles was varied by introduction of varying amounts of positively-charged stearylamine in the membrane surface. Introduction of 0-15 mole% stearylamine in phospholipid vesicles that contained 5 mole% phosphatidylseri-ne (PS) hardly affected their activity in prothrombin activation. Electrophoretic analysis showed that vesicles with > 5 mole% stearylamine had a net positive charge. The procoagulant activity of vesicles that contained phosphatidic acid, phosphatidylglyce-rol, phosphatidylinositol or phosphatidyl-glactate (PLac) as acidic phospholipid was much more effected by incorporation of stearylamine. Amounts of stearylamine that compensated the negative charge of acidic phospholipid caused considerable inhibition of the activity of the latter vesicles in prothrombin activation. The comparison of vesicles containing PS and PLac as acidic phospholipid is of special interest. PS and PLac only differ by the presence of NH+ 3-group in the serine moiety of PS. Thus, in spite of the fact that vesicles with PLac are more negatively charged than vesicles with PS, they are less procoagulant. Our results show that a) although procoagulant membranes have to contain acidic phospholipids there is no requirement for a net negative charge, b) the amino group of phosphatidylserine has an important function in the interaction of procoagulant membranes with vitamin K-dependent proteins and c) the chelation model can satisfactorily explain calcium-mediated lipid-protein association.

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Characterization of Multitermination CG Flashes Using a 3D Lightning Mapping System (FALMA)

Atmosphere ◽

10.3390/atmos10100625 ◽

2019 ◽

Vol 10 (10) ◽

pp. 625 ◽

Cited By ~ 2

Author(s):

Gao ◽

Wang ◽

Shi ◽

Wu ◽

Takagi

Keyword(s):

High Probability ◽

Arithmetic Mean ◽

Time Difference ◽

Return Stroke ◽

Mapping System ◽

Mapping Array ◽

Cg Lightning

We characterized 205 multiple-termination negative cloud-to-ground (CG) lightning flashes that were imaged by the Fast Antenna Lightning Mapping Array (FALMA) in Japan during the summer of 2017. The parameters we used included termination number, termination distance, fork height, return stroke (RS) number, the interval between the first RS of each termination, the shortest time difference between the strokes at different terminations, and the first RS intensities separated by termination occurrence orders. It was found that the multiple-termination flashes (MTFs) had a termination number ranging from 2 to 5, with the majority (148/205) at 2. The termination distance (with high probability) was between 2 and 4 km, with 10 out of 359 MTF termination distances being longer than 10 km. For most MTFs (146/205), their leader forks for different terminations occurred at a height between 4 and 6 km, indicating that the fork process mainly occurred inside the cloud. The RS number of the MTFs ranged from 2 to 18, with an arithmetic mean (AM) value of 5.8. The interval between the first RS of each termination in the MTFs ranged from 0.5 to 965.3 ms, with an AM value of 225.6 ms, while the shortest time difference between the strokes at different terminations had an AM value of 189.6 ms. The intensity of the first stroke in each termination tended to decrease with increasing termination occurrence orders.

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