F. A. Kuterin

Bio: F. A. Kuterin is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Sprite (lightning) & Electric field. The author has an hindex of 5, co-authored 10 publications receiving 49 citations.

Self-Consistent Model of a Night Sprite

Abstract: We propose a radially symmetric self-consistent model of a sprite at altitudes of 60 to 90 km in the region with a radius of 60 km. The perturbations of the densities of ions, electrons, and neutral particles, as well as the photon-emission intensities at the mesospheric altitudes are analyzed with respect to the sprite under night-time conditions. Because of the fast electric-field displacement in the upper part of the diffuse region of the sprite at altitudes of 78 to 81 km, radiation at the discharge axis stops earlier than that in the outer region, i.e., the toroidal structures of the electric field and the sprite radiation are observed. At altitudes of 83 to 87 km, the electrondensity decrease related to the increasing role of the dissociative attachment to molecular oxygen occurs, which significantly decreases conductivity at these altitudes.

Experimental Study of Diurnal and Seasonal Variations in the Atmospheric Electric Field

Abstract: In order to separate global and local effects of atmospheric electricity, measurements of the fair-weather electric field were performed in Nizhny Novgorod in 2013-2018. As a result of processing 139 diurnal records from four observation points spaced 6–8 km apart, diurnal variations in the fair-weather atmospheric electric field for different seasons and weekdays (working days and weekends) were studied. The curve of the local diurnal variation is shown to always have two maxima. The evening maximum of the diurnal variation (19:00–20:00 UT) coincides in time with the maximum of the Carnegie curve, which is a characteristic of the global electrical circuit. The highest values of the field amplitude are reached in the winter period. The field-intensity maximum in the first half of the day (09:00–11:00 LT) is characteristic of the urban environment and shows that local effects associated with the presence of aerosol particles in the air significantly contribute to the formation of diurnal variation, especially in summer. According to the 2013–2018 measurements, the seasonal variation in the monthly-average values of the atmospheric electric field is revealed and analyzed compared with the results of measurements of seasonal variation in other regions of the globe. The obtained results allow one to reveal the role of local effects in the formation of diurnal variation in the mid-latitude areas with temperate continental climate and provide a basis for developing a theory which can explain the physical mechanisms of local effects and suggest appropriate parametrization for finding the surface electric field in the weather and climate models.

One-dimensional self-consistent model of the sprite/halo influence on the mesosphere chemistry

Abstract: The influence of the high-altitude discharges (sprites and halos) on the mesospheric chemical composition and the photon radiation, which is typical of the discharges, is analyzed. A onedimensional self-consistent model of the high-altitude discharges for altitudes of 60 to 90 km, which is the extension of the one-point sprite model [1], is developed. The electric field at the mesospheric altitudes from the noncompensated discharge in a cloud is specified in the dipole approximation with allowance for the features of the current flow in the lightning channel when the cloud–Earth discharge is developed in the troposphere. Perturbation of the ion, electron, and neutral-component densities from the sprite flare and the photon-emission intensity for the sprite and halo is analyzed. The threshold value of the dipole moment, which is required for the sprite initiation, is obtained. The dependence of the size of the diffuse region of the sprite on the dipole moment of the noncompensated electric discharge in the cloud is studied.

Peculiarities of the disturbance in the mesosphere composition and optical emissions caused by high-altitude discharges

Abstract: The suggested equation system, including 267 chemical reactions and corresponding parametrizations of disturbances of the electric field and electron temperature, describes the dynamics of the mesosphere composition under the influence of high-altitude discharges (sprites and halos). Based on this system, the ionic disturbance, neutral components, and optical emissions of the night mesosphere caused by the sprites were modeled for a height of 77–85 km. Most attention was paid to the dynamics of disturbances of concentrations of electrons and O2+, NO+, H3O+, H5O2+, and N2+ typical of the studied heights. The major chemical reactions leading to the disturbance of ionic contents are determined and the relaxation dynamics of the chemical components is reviewed. The account of the excited atoms and molecules of nitrogen and oxygen allowed us to model the radiation of the sprite flash, calculate the volumetric velocity of the photon emission, and study the influence of the sprite on the neutral components of the mesosphere.

This is How the Discussion Started

Abstract: A copy of Guangbo jiemu bao [Broadcast Program Report] was being passed from hand to hand among a group of young people eager to be the first to read the article introducing the program "What Is Revolutionary Love?" It said: "… Young friends, you are certainly very concerned about this problem'. So, we would like you to meet the young women workers Meng Xiaoyu and Meng Yamei and the older cadre Miss Feng. They are the three leading characters in the short story ‘The Place of Love.’ Through the description of the love lives of these three, the story induces us to think deeply about two questions that merit further examination.

Air Plasma Kinetics Under the Influence of Sprites

Abstract: A full time-dependent kinetic study is presented for the main microscopic collisional and radiative processes underlying the optical flashes associated with an impulsive (τ = 5 µs) discharge in the form of a single sprite streamer passing through an air region of the mesosphere at three different altitudes (63, 68 and 78 km). The kinetic formalism developed includes the coupling of the rate equations of each of the different species considered (electrons, ions, atoms and molecules) with the Boltzmann transport equation so that, in this way, all the kinetics is self-consistent, although, in the present approach, the electrodynamics (no Poisson equation is considered) is not coupled. The chemical model set up for air plasmas includes more than 75 species and almost 500 reactions. In addition, a complete set of reactions (more than 110) has been considered to take into account the possible impact of including H2O (humid chemistry) in the generated air plasmas. This study also considers the vibrational kinetics of N2 and CO2 and explicitly evaluates the optical emissions associated with a number of excited states of N2 ,O 2, O in the visible, CO2 in the infrared (IR) and ultraviolet (UV) emissions of sprite streamers due to the N2 Lyman–Birge–Hopfield (LBH) and the NO-γ band systems. All the calculations are conducted for midnight conditions in mid-latitude regions (+38 ◦ N) and 0 ◦ longitude, using as initial values for the neutral species those provided by the latest version of the Whole Atmosphere Community Climate Model (WACCM). According to our calculations, the impact of 4 ppm of H2O is only slightly visible in O − at 68 and 78 km while it strongly affects the behaviour of the anion CO − at all the altitudes investigated. The local enhancement of NOx predicted by the present model varies with the altitude. At 68 km, the concentrations of NO and NO2 increase by about one order of magnitude while that of NO3 exhibits a remarkable growth of up to almost three orders of magnitude. The variation of the O3 density predicted by the model in the sprite streamer head is negligible in all the altitudes investigated. The analysis of the time dependence of the electron distribution function (EDF) in the sprite plasma during the pulse reveals that the EDF transient is quite fast, reaching its ‘steady’ values during the pulse in less than 100 ns (much shorter than streamer head lifetimes). In addition, the calculated EDF during the pulse and in the afterglow is far from being Maxwellian, especially for energetic electrons (with e> 30 eV). Finally, the evaluation of the mid-latitude nighttime electrical conductivity of air plasmas under the influence of a single sprite event reveals an increase of up to four orders of magnitude (at 68 km) above its measured background level of 10 −11 cm −1 at an altitude of ∼70 km. This sudden increase in the electrical conductivity lasts for 100 ms (at 68 km), being shorter (∼1 ms) and longer (1 s) at 63 km and 78 km, respectively. The total power delivered by the streamer head of a single sprite event has been estimated to be approximately 1677 W (at 78 km), 230 kW (at 68 km) and 78 MW (at 63 km). (Some figures in this article are in colour only in the electronic version)

Plasma Chemistry of Sprite Streamers

Abstract: A study is conducted of the principal chemical effects induced by the passage of a single sprite streamer through the mesosphere at an altitude of 70 km. Recent high-speed imaging of sprite streamers has revealed them to comprise bright (1-100 GR), compact (decameter-scale) heads moving at ∼10 7 m s -1 . On the basis of these observations, a quantitative model of the chemical dynamics of the streamer head and trailing region is constructed using a nonlinear coupled kinetic scheme of 80+ species and 800+ reactions. In this initial study, chemical processes related to currents in the trailing column and to vibrational kinetics of N 2 and O 2 are not included. The descending streamer head impulsively (T ∼ 10 μs) ionizes the gas (fractional ionization density ∼10 -9 ), leaving in its trail a large population of ions, and dissociated and excited neutral byproducts. Electrons created by ionization within the head persist within the trailing column for about 1 s, with losses occurring approximately equally by dissociative attachment with ambient O 3 , and by dissociative recombination with the positive ion cluster N 2 O + 2 . The ion cluster is produced within the trailing channel by a three-step process involving ionization of N 2 , N + 2 charge exchange with O 2 , and finally three-body creation of N 2 O + 2 . On the basis of simulation results, it is concluded that the observed reignition of sprites most likely originates in remnant patches of cold electrons in the decaying streamer channels of a previous sprite. Relatively large populations (fractional densities ∼10 -9 -10 -8 ) of the metastable species O( 1 D), O( 1 S), N( 2 D), O 2 (a 1 Δ g ), O 2 (b 1 Σ + g ), N 2 (A 3 Σ + u ), and N 2 (a' 1 Σ - u ) are created in the streamer head. The impulsive creation of these species initiates numerous coupled reaction chains, with most of the consequent effects being of a transient nature persisting for less than 1 s. These include weak (∼1 kR), but possibly detectable, OI 557.7 nm and O 2 (b 1 Σ + g → X 3 Σ - g ) Atmospheric airglow emissions. Neutral active species created in the greatest abundance (fractional densities > 10 -8 ) are N 2 (X 1 Σ + g , ν), O( 3 P), N( 4 S), and O 2 (a 1 Δ g ), which, because of the absence of readily available chemical dissipation channels, persist for longer than 100s of seconds. Other long-lived (>1000 s) effects are very weak (∼1-10 R) OH(X 2 Π, ν = 6...9 - Δν) Meinel emissions produced by O( 3 P)-enhanced OH catalysis and O 2 (a 1 Δ g → X 3 Σ - g ) Infrared Atmospheric emissions. Short-lived (∼100 s) populations of hydrated positive ions and negative ion clusters are also created in the streamer trail. Electron impact dissociated N( 2 D) interacts with O 2 to create a long-lived (>1000 s) increase (fractional enhancement ∼75%) of the ambient NO density within the streamer channel, for a net production of ∼5 x 10 19 NO molecules for the streamer as a whole. It is suggested that in addition to the optical emissions from electron-impact excited electronic states of N 2 , a substantial portion of the spectrum may be due to chemiluminescent processes derived from vibrational kinetics of nitrogen.

Chemical and thermal impacts of sprite streamers in the Earth's mesosphere

Abstract: This work was supported by the Spanish Ministry of Economy and Competitiveness, MINECO, under projects AYA2011-29936-C05-02 and ESP2013-48032-C5-5-R and by the Junta de Andalucia, Proyecto de Excelencia, FQM-5965. F.C.P.R. acknowledges MINECO for the FPI grant BES-2010-042367. A.L. was supported by a Ramon y Cajal contract, code RYC-2011-07801