Ball lightning caused by a semi-relativistic runaway electron avalanche

The study of the Earth’s atmosphere and the space environment is important because of the role played by the medium in the activities that affect the Earth and its inhabitants directly or indirectly. A robust capability to monitor, model and predict the happenings in the atmospheric space through deployment of both space- and ground-based observational systems for data acquisition, is key to result-oriented scientific research in atmospheric and space sciences. In this paper, we highlight the importance of regional deployment of observational facilities for data acquisition to complement current observational tools. We briefly review the capabilities of very low frequency (VLF) radio waves (in monitoring and studying changes in the atmosphere and ionosphere), and also present data obtained from our newly deployed VLF radio waves receiver at Anchor University, Lagos (AUL). We show that the diurnal signature characterised by VLF radio signal reflected in the data of three of four propagation paths (AUL-HWU, AUL-JJI, AUL-NWC and AUL-VTX) received at AUL. This outcome shows that operational condition of the VLF radio wave receiver is good. We anticipate interesting findings as we exploit this institution-based dataset to probe ionospheric irregularities in our region for the first time. In the light of some identified ionospheric changes in the equatorial region, we anticipate that our research effort using this regional VLF dataset will yield new results that will be resourceful for better understanding and characterisation of the dynamics of the equatorial D-layer ionosphere, since our region of reception (Lagos) lies close to the equator.

We discuss the current understanding of the nature and features of the ball lightning. Existing models for the formation and function of luminous spherical objects in the atmosphere are observed. The core features of the author's kvataron model are presented in detail. According to this model, the ball lightning is interpreted as a Coulomb crystal composed of charged clusters from a "hidden" phase — referred to as kvatarons. The model posits that the structural integrity and stability of ball lightning are maintained primarily by its internal crystalline lattice and surface energy. Crucially, the energy stored within the ball lightning, which is irradiated, is neither replenished from an external source nor is it derived from chemical energy.

Very low frequency (VLF) radio waves have very effective long-distance propagation characteristics. Therefore, they have a wide application prospect in underwater and underground communication. To effectively suppress the interference of channel noise and improve the performance of the VLF communication system, a low-density parity check (LDPC) coded orthogonal frequency division multiplexing-minimum frequency shift keying (OFDM-MSK) communication scheme is designed according to the characteristics of the VLF channel. Considering that the harmonic interference in the VLF channel can be regarded as frequency selective fading, the OFDM technology is applied to the VLF channel. In addition, the performance of VLF communication system is mainly affected by strong impulse atmospheric noise, which can be successfully simulated by symmetrical alpha stable (SαS) distribution. To reduce the impact of SαS noise on the OFDM system and data loss in frequency selective fading channel, LDPC channel coding technology is proposed. Finally, the robustness of the LDPC coded OFDM-MSK scheme is tested and evaluated from the perspective of the bit error rate (BER). The results show that the LDPC coded OFDM-MSK communication scheme has better performance than the independent OFDM-MSK communication scheme.

There are several sources of high energy radiations in the Universe. Each of them has a totally different emission mechanism. In this review, I concentrate on the study of the general properties of radiations emitted by matter which are accreted towards black holes and neutron stars. We also study the nature of X-ray radiation coming from the Sun in the form of energetic solar flares. These radiations are constantly bombarding the Earth’s ionosphere changing its electron content and affecting the wave propagation through the Earth and the lower-ionosphere waveguide. We monitor Very Low Frequency (VLF) radio waves and correlate our observations with the presence or absence of the high energy radiations from space. Our results during solar flares, show how the number density of the ionosphere is enhanced by these celestial sources. The terrestrial high energy phenomena such as earthquakes are believed to affect the ionospheric properties and we have monitored VLF signals during earthquakes and found possible effects of seismic events on the VLF signals.

An eyewitness sees ball lightning as a luminous sphere in regions of thunderstorm activity. There are many reports of ball lightning forming after a lightning discharge, existing for several seconds, and terminating suddenly and silently, or exploding with or without material damage1,2. Jennison3 has described ball lightning observed at close range inside a commercial aircraft shortly after a lightning discharge. As it drifted down the aisle of the passenger cabin, this ball lightning exhibited: (1) perfect equilibrium in a perfectly spherical shape with diameter 22±2 cm; (2) 5–10 W of optical radiation in blue-white light, but no heat radiation; and (3) an optically thick surface of almost solid appearance, devoid of polar or toroidal structure, but with some limb-darkening. It seems unreasonable to dismiss Jennison's ball lightning as an optical illusion4 (afterimage of the eye's retina). A physical explanation in terms of a microwave cavity5, a d.c. glow discharge6, chemical reactions7, nuclear reactions8 or annihilation of antimatter9 runs into difficulties since the all-metal airplane structure would act effectively as an air-tight Faraday cage. A plethora of excited atoms and molecules, and electromagnetic waves ranging from radio frequencies to X rays are produced in the channel of a lightning discharge, but only electric charge itself can enter the interior of an all-metal airplane without difficulty. Here a new model is presented which explains ball lightning in terms of electric charge.

Phenomenon of ball lightning and its outgrowths

Many patients with severe obstructive sleep apnea (OSA) do not complain of excessive daytime sleepiness (EDS), possibly due to increased sympathetic nervous activity (SNA) and accompanying heightened alertness. We hypothesized that in patients with OSA, those without subjective EDS (Epworth Sleepiness Scale, ESS score < 11) would have higher very low frequency (VLF) heart rate variability (HRV) during sleep, reflecting greater sympathetic heart rate modulation than patients with an ESS score ≥ 11. Patients with severe OSA (AHI ≥ 30: 26 with and 65 without heart failure) were divided into those with and without EDS. Heart rate (HR) signals were acquired in stage 2 sleep during periods of recurrent apneas and hypopneas and submitted to coarse graining spectral analysis, which extracts harmonic, neurally mediated contributions to HRV from total spectral power. Because the apnea-hyperpnea cycle entrains muscle SNA at VLF (0 to 0.04 Hz), VLF power was our principal between-group comparison. Subjects without EDS had higher harmonic VLF power (944 ± 839 vs 447 ± 461 msec(2), p = 0.003) than those with EDS, irrespective of the presence or absence of heart failure (1218 ± 944 vs 426 ± 299 msec(2), p = 0.043, and 1029 ± 873 vs 503 ± 533 msec(2), p = 0.003, respectively). ESS scores correlated inversely with VLF power in all (r = -0.294, p = 0.005) and in heart failure subjects (r = -0.468, p = 0.016). Patients with severe OSA but without EDS have higher VLF-HRV than those with EDS. This finding suggests that patients with severe OSA but without EDS have greater sympathetic modulation of HRV than those with EDS that may reflect elevated adrenergically mediated alertness. Taranto Montemurro L; Floras JS; Picton P; Kasai T; Alshaer H; Gabriel JM; Bradley TD. Relationship of heart rate variability to sleepiness in patients with obstructive sleep apnea with and without heart failure.

&amp;lt;p&amp;gt;The seasonal variation of the daytime lower ionosphere, monitored using the propagation of Very Low Frequency (VLF) radio waves, shows an asymmetry when comparing the spring and autumn transitions. Considering the solar zenith angle variation, it can explain the spring transition but not the autumn one. The climatological variation exposes that the maximum of the VLF deviation is around the beginning of October. Thus, the deviation is called &amp;amp;#8220;the October effect&amp;amp;#8221;. This study aims to understand the possible atmospheric phenomena behind this effect. We use VLF signals transmitted from USA (NAA, f = 24 kHz), UK (GQD, f=19.6 kHz) and Iceland (NRK, f = 37.5 kHz) recorded in Northern Finland from 2011 to 2019. We compare our results with the Whole Atmosphere Community Climate Model with the thermosphere-ionosphere eXtension (WACCM-X) data. The October effect is separated into climatological earliest and latest effect according to WACCM-X climatological earliest and latest transitions from eastward to westward mean zonal winds&amp;lt;/p&amp;gt;

A proposed theory of the phenomenon of ball lightning

Ball lightnings are considered to be electrostatically bipolar charged shells of orderly oriented water molecules. The time of life of this model for ball lightnings of typical sizes is shown to exceed tens of seconds, the energy being caused by orientation of dipolar water molecules. Issues pertaining to ball lightning formation, stability, and specialties of motion are discussed.

Investigations on Lanthanide polymers for radiation shielding purpose

BALL lightning is characterized by the presence of a luminous mobile globe of high energy density produced in regions of considerable electrical activity. The properties of ball lightning have been outlined in recent surveys1–4. We are interested here in the few but significant cases of high energy ball lightning.

We present a tomographic imaging technique for the D‐region electron density using a set of spatially distributed very low frequency (VLF) remote sensing measurements. The D‐region ionosphere plays a critical role in many long‐range and over‐the‐horizon communication systems; however, it is unreachable by most direct measurement techniques such as balloons and satellites. Fortunately, the D region, combined with Earth's surface, forms what is known as the Earth‐Ionosphere waveguide allowing VLF and low frequency (LF) radio waves to propagate to global distances. By measuring these signals, we can estimate a path measurement of the electron density, which we assume to be a path‐averaged electron density profile of the D region. In this work, we use path‐averaged inferences from lightning‐generated radio atmospherics (sferics) with a tomographic inversion to produce 3D models of electron density over the Southeastern United States and the Gulf of Mexico. The model begins with two‐dimensional great circle path observations, each of which is parameterized so it includes vertical profile information. The tomography is then solved in two dimensions (latitude and longitude) at arbitrarily many altitude slices to construct the 3D electron density. We examine the model's performance in the synthetic case and determine that we have an expected percent error better than 10% within our area of interest. We apply our model to the 2017 “Great American Solar Eclipse” and find a clear relationship between sunlight percentage and electron density at different altitudes.

Summary form only given. The possibility of ball lightning formation by rocket-triggered lightning with a grounded trailing inductive coil has been suggested in my paper, 7E05: EHD and MHD Models of Fireballs and Their Relevance to Natural and Artificial Ball Lightning for the Oral Session 7E: 4.6 Spherical Configuration/Ball Lightning at the ICOPS 97, p.319. The present paper proceeds in more detail along this line.

CONTENTS Introduction 743 1. Observational Data on Natural Low-Frequency Radio Emission 744 a) Whistlers 745 Dispersion. Long and short whistlers. Multiple whistlers. Nose whistlers. Discharges that generate whistlers. Experimental data on the trajectories of whistlers. Systematic variations of properties of whistlers. Observation of whistlers in the IGY program. b) Very Low Frequency Emissions 749 Systematic classification of observed VLF noise. Certain features of discrete radiation. Method of propagation. Tendency to form horizontal or gliding tones. Connection with magnetic activity. Comparison of steady states (hissing) with transients (discrete radiation). 2. Theory of Propagation of Low-Frequency Radio Waves. Generation of VLF Emissions 751 Principal initial relations. Group velocity and determination of trajectories. Allowance for ion motion. Interaction of normal waves. Absorption. Mechanisms of generation of VLF emissions. 3. Low Frequency Radio Waves and Investigation of the Upper Atmosphere 761 Conclusion 763 Cited Literature 763