The Influence of Smoke From Forest Fires on the Meteorological and Electrical Characteristics of the Atmosphere

2020 ◽  
pp. 322-344
Author(s):  
Petr Mikhailovich Nagorskiy ◽  
Mikhail Vsevolodovich Kabanov ◽  
Konstantin Nikolaevich Pustovalov
Keyword(s):  
Surface Layer ◽  
Water Vapor ◽  
Forest Fires ◽  
Western Siberia ◽  
Moisture Transfer ◽  
Diurnal Variations ◽  
Volume Charge ◽  
Homogeneous Surface ◽  
Near Surface ◽  
The Impact

The impact of smoke from forest fires in western Siberia on meteorological, atmospheric electric, and aerological variables has been analyzed. The anomalous distribution of water vapor in the atmosphere associated with the peculiarities of the evaporation regime and the absence of advective moisture transfer over the southern regions of Western Siberia during the fires. With an increase in the height of the homogeneous surface smoke layer with an unchanged aerosol optical thickness, the cooling of the earth's surface and heating of the atmosphere was weakened. The smoke plume spreads predominantly in the middle of the troposphere, creating aerosol layers elevated above the ground, the lower part of which had a negative volume charge. The effect of diurnal variations in the electrical field in the near-surface layer, differs from the known similar effects.

scholarly journals Unmanned aerial vehicles reveal the impact of a total solar eclipse on the atmospheric surface layer

2019 ◽  
Vol 475 (2229) ◽  
pp. 20190212 ◽  
Author(s):  
Sean C. C. Bailey ◽  
Caleb A. Canter ◽  
Michael P. Sama ◽  
Adam L. Houston ◽  
Suzanne Weaver Smith
Keyword(s):  
Surface Layer ◽  
Unmanned Aerial Vehicles ◽  
Solar Eclipse ◽  
Atmospheric Surface Layer ◽  
Small Scale ◽  
Stable Layer ◽  
Holistic View ◽  
Near Surface ◽  
Aerial Vehicles ◽  
The Impact

We use unmanned aerial vehicles to interrogate the surface layer processes during a solar eclipse and gain a comprehensive look at the changes made to the atmospheric surface layer as a result of the rapid change of insolation. Measurements of the atmospheric surface layer structure made by the unmanned systems are connected to surface measurements to provide a holistic view of the impact of the eclipse on the near-surface behaviour, large-scale turbulent structures and small-scale turbulent dynamics. Different regimes of atmospheric surface layer behaviour were identified, with the most significant impact including the formation of a stable layer just after totality and evidence of Kelvin–Helmholtz waves appearing at the interface between this layer and the residual layer forming above it. The decrease in surface heating caused a commensurate decrease in buoyant turbulent production, which resulted in a rapid decay of the turbulence in the atmospheric surface layer both within the stable layer and in the mixed layer forming above it. Significant changes in the wind direction were imposed by the decrease in insolation, with evidence supporting the formation of a nocturnal jet, as well as backing of the wind vector within the stable layer.

scholarly journals Influence of Atmosphere Near-Surface Layer Properties on Development of Cloud Convection

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 131 ◽  
Author(s):  
Magomet Abshaev ◽  
Robert Zakinyan ◽  
Ali Abshaev ◽  
Qasim Al-Owaidi ◽  
Ludmila Kulgina ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Surface Layer ◽  
Water Vapor ◽  
Mass Fraction ◽  
Dew Point ◽  
Two Dimensional ◽  
Near Surface ◽  
Air Heating ◽  
Vapor Mass ◽  
Stimulation Of

A two-dimensional mathematical model of moist air convection in the sub-cloud and cloud layers is proposed. A theoretical analysis of the influence of near ground atmospheric parameters on the development of sub-cloud and cloud convection is provided, and the criteria of convection development are considered. As a rule, this relationship is parameterized in general circulation, regional or mesoscale models of the atmosphere. Therefore, achieving a more complete and correct understanding of this relationship can lead to an improvement in the accuracy of weather forecasts. The mathematical model describes the system of the equations of motion, heat conductivity and the continuity equations for a two-dimensional vertical plane. The approximate analytical solution of the system of equations is obtained. Expressions for the estimation of the convection height and height of maximum velocity are derived for vertical and horizontal components of updraft wind and for vertical distribution of temperature. From the expressions obtained, the criterion of sub-cloud convection development is derived. The expressions for the convection parameters at a condensation level have also been formulated, from which the criterion of cloud development through convection is derived. It is established that the development of cloud convection depends on absolute values of the dew point deficit in a near-surface layer and, in a greater degree, on vertical gradients of water vapor mass fraction. It is shown that at certain critical values of a vertical gradient of water vapor mass fraction “explosive convective growth” is observed. The application of the obtained results to artificial stimulation of convection by means of air heating in the near-ground atmosphere has shown that the success of such an application and the required air heating-up depend on: (i) the vertical temperature gradient; (ii) the vertical dew-point gradient; and (iii) the value of the dew point deficit in the near-ground layer. The analysis performed has shown the possibility of successful stimulation of artificial convection under specific favorable atmospheric conditions.

Monitoring of the temperature distribution in prediction of forest fires

2015 ◽  
Vol 5 (4) ◽  
pp. 16-25 ◽  
Author(s):  
Камалова ◽  
Nina Kamalova ◽  
Евсикова ◽  
Natalya Evsikova ◽  
Матвеев ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Electric Fields ◽  
Forest Fires ◽  
Woody Plants ◽  
Moisture Transfer ◽  
Moisture Loss ◽  
Effect Of Temperature ◽  
Conceptual Approach ◽  
Relative Change ◽  
The Impact

The article proposes to develop a conceptual approach to the prediction of forest fires. The issue on the impact of temperature changes during the year on the accumulation of moisture in the forest litter is considered. Equation for estimating the relative change of water reserve in the litter depending on the ambient temperature relative change is obtained. It is shown that the availability of winter thaws promotes the accumulation of moisture in the soil and the absence of a thaw in the winter can cause to the consolidation of moisture only on the surface in the form of snow or ice. It is increasing probability of moisture loss after a large spring snow melting and provides grounds for the forecast of increasing the risk of forest fire danger in the summer. The effect of temperature distribution along the radius of the trunk of woody plants in the processes of moisture transfer is considered. It is shown that an electric fields arise in tree trunks in the direction along the radius and along the axis of the tree trunk from exposure of nonuniform temperature field. This fact allows speaking about presence of an electrical mechanism of moisture transfer in the pores of the trunks of woody plants. This mechanism coexists with other mechanisms of sap flow in the summer months because of the existence of temperature difference at the change of day and night. If the tempera-ture of the day and night are almost identical, then the electrical mechanism of moisture redistribution in the stems of woody plants stops, and the risk of fire increases. Monitoring of the temperature distribution in the litter and in the trunks of woody plants using digital sensors with controlled accuracy will predict the likelihood of forest fires in advance.

Phase transformations in nitrided ferrovanadium under the action of a high power carbon ion beams

2020 ◽  
Vol 5 ◽  
pp. 11-23
Author(s):  
G.V. Potemkin ◽  
◽  
O.K. Lepakova ◽  
V.D. Kitler ◽  
M.V. Zhidkov ◽  
...  
Keyword(s):  
Surface Layer ◽  
High Power ◽  
High Speed ◽  
Ion Beam ◽  
Vanadium Nitride ◽  
Carbon Ions ◽  
Translational Invariance ◽  
Near Surface ◽  
Modified Layer ◽  
The Impact

The phase and elemental composition of the near-surface layer of nitrided ferrovanadium irradiated with a high-power ion beam has been investigated by XRD and SEM methods. The impact of a powerful beam of the Temp-4M setup with an energy of carbon ions of 250 keV at a radiation pulse duration 10–7 s and a power density of charged particles qi ≥ 106 W/cm2 causes melting of the Fe-VN composite and partial evaporation of elements with a high vapor pressure from the surface layer. High-speed solidification of the melt on the surface of the Fe-VN target leads to the formation of highly dispersed vanadium nitride and tetragonal carbide Fe23C6 in the modified layer. After irradiation of Fe-VN with a high-power beam with qi ≈ 107 W/cm2 at a dose of ~ 1015 cm–2, a violation of the translational invariance of the distribution of intercalated carbon atoms, a structural redistribution of Fe and V atoms, and the formation of X-ray amorphous microliquations of Fe-V and gas-carbon complexes are observed in the modified layer.

Recombination Characteristics of Single-Crystalline Silicon Wafers with a Damaged Near-Surface Layer

2013 ◽  
Vol 58 (2) ◽  
pp. 142-150 ◽  
Author(s):  
A.V. Sachenko ◽  
◽  
V.P. Kostylev ◽  
V.G. Litovchenko ◽  
V.G. Popov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Crystalline Silicon ◽  
Silicon Wafers ◽  
Single Crystalline Silicon ◽  
Near Surface ◽  
Single Crystalline

scholarly journals The Impact of the Electric Field on Surface Condensation of Water Vapor: Insight from Molecular Dynamics Simulation

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 64 ◽  
Author(s):  
Qin Wang ◽  
Hui Xie ◽  
Zhiming Hu ◽  
Chao Liu
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Electric Field ◽  
Intermolecular Forces ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Attraction Force ◽  
Condensation Rate ◽  
Shape Transformation ◽  
The Impact

In this study, molecular dynamics simulations were carried out to study the coupling effect of electric field strength and surface wettability on the condensation process of water vapor. Our results show that an electric field can rotate water molecules upward and restrict condensation. Formed clusters are stretched to become columns above the threshold strength of the field, causing the condensation rate to drop quickly. The enhancement of surface attraction force boosts the rearrangement of water molecules adjacent to the surface and exaggerates the threshold value for shape transformation. In addition, the contact area between clusters and the surface increases with increasing amounts of surface attraction force, which raises the condensation efficiency. Thus, the condensation rate of water vapor on a surface under an electric field is determined by competition between intermolecular forces from the electric field and the surface.

scholarly journals An Evaluation of the Impact of the Amount of Potassium Hydroxide on the Porous Structure Development of Activated Carbons

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2045
Author(s):  
Mirosław Kwiatkowski ◽  
Elżbieta Broniek ◽  
Vanessa Fierro ◽  
Alain Celzard
Keyword(s):  
Density Functional Theory ◽  
Porous Structure ◽  
Potassium Hydroxide ◽  
Density Functional ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Appropriate Technology ◽  
Functional Theory ◽  
Homogeneous Surface ◽  
The Impact

This paper presents the results of an evaluation of the impact of the amount of potassium hydroxide on the obtained porous structure of the activated carbons derived from the shells of pistachios, hazelnuts, and pecans by carbonization and subsequent chemical activation with potassium hydroxide by different adsorption methods: Brunauer–Emmett–Teller, Dubinin–Raduskevich, the new numerical clustering-based adsorption analysis, Quenched Solid Density Functional Theory, and 2D-Non-linear Density Functional Theory for Heterogeneous Surfaces, applied to nitrogen adsorption isotherms at −196 °C. Based on the conducted research, a significant potential for the production of activated carbons from waste materials, such as nut shells, has been demonstrated. All the activated carbons obtained in the present study at the activator/char mass ratio R = 4 exhibited the most developed porous structure, and thus very good adsorption properties. However, activated carbons obtained from pecan shells deserve special attention, as they were characterized by the most homogeneous surface among all the samples analyzed, i.e., by a very desirable feature in most adsorption processes. The paper demonstrates the necessity of using different methods to analyze the porous structure of activated carbons in order to obtain a complete picture of the studied texture. This is because only a full spectrum of information allows for correctly selecting the appropriate technology and conditions for the production of activated carbons dedicated to specific industrial applications. As shown in this work, relying only on the simplest methods of adsorption isotherm analysis can lead to erroneous conclusions due to lack of complete information on the analyzed porous structure. This work thus also explains how and why the usual characterizations of the porous structure of activated carbons derived from lignocellulosic biomass should not be taken at face value. On the contrary, it is advisable to cross reference several models to get a precise idea of the adsorbent properties of these materials, and therefore to propose the most suitable production technology, as well as the conditions of the preparation process.

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