scholarly journals Stability of equilibrium in a one-dimensional hydrostatic model of the dry atmosphere

2020 ◽  
Vol 4 ◽  
pp. 104-120
Author(s):  
S.M. Semenov ◽  
◽  
◽  
Keyword(s):  
Temperature Distribution ◽  
Negative Temperature ◽  
Initial Distribution ◽  
Ideal Gas ◽  
Underlying Surface ◽  
Wave Radiation ◽  
Radiation Balance ◽  
One Dimensional ◽  
Atmospheric Column ◽  
Hydrostatic Model

Experts in the field of mathematical modeling of the climate system have different views about which class of models should be employed to analyze and predict climate for time scales corresponding to climatic processes. In this paper, we investigate the properties of a model constructed using the hydrostatic hypothesis. A one-dimensional (horizontally homogeneous) hydrostatic model of a dry atmosphere is considered. Air is considered an ideal gas. The source of heat is the external short-wave radiation flux entering the upper boundary of the atmosphere. This energy is partly absorbed by the atmospheric layers and the underlying surface, partly returned to space. The atmospheric layers and the underlying surface radiate in the long-wave range. In general, the absorption coefficient and heat capacity are specific for the atmospheric layers and are everywhere positive. In the model, the radiation balance of a segment of the atmospheric column above a unit area of the underlying surface determines the change in the internal energy and the volume occupied by the segment.The pressure value always remains equal to the weight of a part of the atmospheric column above the segment (hydrostatic hypothesis). The underlying surface is always in the state of radiation equilibrium. Under these assumptions: a) there is a single equilibrium vertical temperature distribution in the column and corresponding air pressure and density distributions (they are calculated using the hydrostatic assumption and the equation of a state of the ideal gas); b) the temperature distribution is asymptotically stable, i.e. any other initial distribution of non-negative temperature values tends with time to equilibrium uniformly on the vertical. Thus, one can expect that the numerical analogs of the model considered in this work will also be stable, which is important for the computational implementation of both the one-dimensional model and its three-dimensional version.

The combined effect of lattice’s uniaxial strains and electron–phonon interaction’s screening on TBEC of the intersite bipolarons

2016 ◽  
Vol 30 (26) ◽  
pp. 1650186
Author(s):  
B. Yavidov ◽  
SH. Djumanov ◽  
T. Saparbaev ◽  
O. Ganiyev ◽  
S. Zholdassova ◽  
...  
Keyword(s):  
Ideal Gas ◽  
Einstein Condensation ◽  
Chain Model ◽  
One Dimensional ◽  
Electron Phonon Interaction ◽  
Model Lattice ◽  
Experimental Values ◽  
Bose Einstein ◽  
Derivatives Of ◽  
The Ideal

Having accepted a more generalized form for density-displacement type electron–phonon interaction (EPI) force we studied the simultaneous effect of uniaxial strains and EPI’s screening on the temperature of Bose–Einstein condensation [Formula: see text] of the ideal gas of intersite bipolarons. [Formula: see text] of the ideal gas of intersite bipolarons is calculated as a function of both strain and screening radius for a one-dimensional chain model of cuprates within the framework of Extended Holstein–Hubbard model. It is shown that the chain model lattice comprises the essential features of cuprates regarding of strain and screening effects on transition temperature [Formula: see text] of superconductivity. The obtained values of strain derivatives of [Formula: see text] [Formula: see text] are in qualitative agreement with the experimental values of [Formula: see text] [Formula: see text] of La[Formula: see text]Sr[Formula: see text]CuO4 under moderate screening regimes.

A Study of a Sharp 90 Degree Curved Flow

1992 ◽  
Author(s):  
R. H. Kim
Keyword(s):  
Turbulence Model ◽  
Ideal Gas ◽  
Radius Of Curvature ◽  
Dimensional Theory ◽  
One Dimensional ◽  
Algebraic Stress Model ◽  
Finite Difference Technique ◽  
Curved Tube ◽  
Kinetic Energy Loss ◽  
The Ideal

Abstract An investigation of air flow along a 90 degree elbow-like tube is conducted to determine the velocity and temperature distributions of the flow. The tube has a sharp 90 degree turn with a radius of curvature of almost zero. The flow is assumed to be a steady two-dimensional turbulent flow satisfying the ideal gas relation. The flow will be analyzed using a finite difference technique with the K-ε turbulence model, and the algebraic stress model (ASM). The FLUENT code was used to determine the parameter distributions in the passage. There are certain conditions for which the K-ε model does not describe the fluid phenomenon properly. For these conditions, an alternative turbulence model, the ASM with or without QUICK was employed. FLUENT has these models among its features. The results are compared with the result computed by using elementary one-dimensional theory including the kinetic energy loss along the passage of the sharp 90 degree curved tube.

Statistical mechanics of one-dimensional solitary-wave-bearing scalar fields: Exact results and ideal-gas phenomenology

1980 ◽  
Vol 22 (2) ◽  
pp. 477-496 ◽  
Author(s):  
J. F. Currie ◽  
J. A. Krumhansl ◽  
A. R. Bishop ◽  
S. E. Trullinger
Keyword(s):  
Solitary Wave ◽  
Statistical Mechanics ◽  
Scalar Fields ◽  
Ideal Gas ◽  
Exact Results ◽  
One Dimensional

scholarly journals The Influence of Cloudiness on The Net Radiation Balance of A Snow Surface with High Albedo

1974 ◽  
Vol 13 (67) ◽  
pp. 73-84 ◽  
Author(s):  
W. Ambach
Keyword(s):  
Greenland Ice Sheet ◽  
Short Wave ◽  
Mean Value ◽  
Wave Radiation ◽  
Radiation Balance ◽  
Net Radiation ◽  
Long Wave ◽  
Energy Excess ◽  
Overcast Sky ◽  
Long Wave Radiation

The short-wave and long-wave radiant fluxes measured in the accumulation area of the Greenland ice sheet during a mid-summer period are discussed with respect to their dependence on cloudiness. At a cloudiness of 10/10, a mean value of 270 J/cm2 d is obtained for the daily totals of net radiation balance, whereas a mean value of only 75 J/cm2 d is observed at 0/10. The energy excess of the net radiation balance with overcast sky is due to the significant influence of the incoming long-wave radiation and the high albedo of the surface (average of 84%). High values of net radiation balance are therefore correlated with high values of long-wave radiation balance and low values of short-wave radiation balance.

The Structure of Laminar Premixed H2-Air Flames at Elevated Pressures

2000 ◽  
Vol 214 (4) ◽  
Author(s):  
M. El-Gamal ◽  
E. Gutheil ◽  
J. Warnatz
Keyword(s):  
Laminar Flame ◽  
Flame Structure ◽  
Ideal Gas ◽  
Fortran Program ◽  
Laminar Flame Speed ◽  
Real Gas ◽  
One Dimensional ◽  
Rocket Propulsion ◽  
Elevated Pressures ◽  
Engine Combustion

In high-pressure flames that occur in many practical combustion devices such as industrial furnaces, rocket propulsion and internal engine combustion, the assumption of an ideal gas is not appropriate. The present paper presents a model that includes modifications of the equation of state, transport and thermodynamic properties. The model is implemented into a Fortran program that was developed to simulate numerically one-dimensional planar premixed flames. The influence of the modifications for the real gas behavior on the laminar flame speed and on flame structure is illustrated for stoichiometric H

scholarly journals Equilibrium and nonequilibrium description of negative temperature states in a one-dimensional lattice using a wave kinetic approach

2022 ◽  
Vol 105 (1) ◽  
Author(s):  
M. Onorato ◽  
G. Dematteis ◽  
D. Proment ◽  
A. Pezzi ◽  
M. Ballarin ◽  
...  
Keyword(s):  
Negative Temperature ◽  
Kinetic Approach ◽  
Dimensional Lattice ◽  
One Dimensional

scholarly journals Data visualization and distinct features extraction of the comet Ison 2013

2019 ◽  
Vol 12 (24) ◽  
pp. 122-128
Author(s):  
Salman. Z. Khalaf
Keyword(s):  
Temperature Distribution ◽  
Data Visualization ◽  
Features Extraction ◽  
Maximum Intensity ◽  
Distribution Fitting ◽  
One Dimensional ◽  
Mathematical Equations ◽  
Distinct Features

The distribution of the intensity of the comet Ison C/2013 is studied by taking its histogram. This distribution reveals four distinct regions that related to the background, tail, coma and nucleus. One dimensional temperature distribution fitting is achieved by using two mathematical equations that related to the coordinate of the center of the comet. The quiver plot of the gradient of the comet shows very clearly that arrows headed towards the maximum intensity of the comet.

On Burgers Equation for a Wave Propagation in One-Dimensional Ideal Gas

1987 ◽  
Vol 499 (6) ◽  
pp. 468-470
Author(s):  
K. Murawski ◽  
J. Kukiełka ◽  
R. Koper
Keyword(s):  
Wave Propagation ◽  
Burgers Equation ◽  
Ideal Gas ◽  
One Dimensional

Thermal regime of soil active layer at the Bolshevik Island (Archipelago Severnaya Zemlya) during 2016 – 2020 years

2021 ◽  
Author(s):  
Alexander Makshtas ◽  
Petr Bogorodski ◽  
Ilya Jozhikov
Keyword(s):  
Heat Flux ◽  
Spatial Variability ◽  
Active Layer ◽  
Thermal Regime ◽  
Soil Layer ◽  
Underlying Surface ◽  
Wave Radiation ◽  
Heat Flux Sensor ◽  
Research Station ◽  
Contact Method

<p>Investigations of active soil layer on the Research station “Ice Base Cape Baranova’’ had been started in February 2016 after installation on the meteorological site sensors of Finnish Meteorological Institute: thermochain with IKES PT00 temperature sensors at depths of 20, 40, 60, 80 and 100 cm, soil heat flux sensor HFP, and two ThetaProbe type ML3 soil moisture sensors. Based on the results of measurements annual cycle of soil temperature changes was revealed with amplitudes 10 - 15 ° C less than the amplitudes of surface air layer temperature (Ta) and especially the temperature of the soil upper surface (Tsrad), in great degree determined by short-wave radiation heating and long-wave radiation cooling. Approximation by linear fittings shows average rates of increase Ta - 0.4°C/year, Тsrad - 0.3°C/year, and temperatures of active soil layer - 0.2°C/year.</p><p>The data on thermal regime of active soil layer and characteristics of energy exchange in atmospheric surface layer make it possible to draw the conclusion about the reason for the abnormally warm state of the upper meter soil layer in summer 2020, despite in March during the whole period under study active soil layer was the warmest in 2017. Comparison in temperatures of the underlying surface and characteristics of surface heat balance during period under study showed that in 2020 the temperature of the soil surface at the end of May for a short time reached the temperature of snow melting. It is happened 25 days earlier than in 2017 as well as other years and led to radical decrease in surface albedo, sharp increase of heat flux to the underlying surface, and increased duration of active soil layer heating.</p><p>Additionally, permafrost thawing studies using a manual contact method were carried out on the special site, organized according to CALM standards. These studies showed significant variety of soil active layer thicknesses in the relatively small area (~0.12 km<sup>2</sup>), which indicates significant spatial variability of microrelief, structure and thermophysical properties of soil, as well as vegetation, typical for Arctic desert. Calculations carried out with version of the well-known thermodynamic Leibenzon model for various parameterizations of vegetation and soil properties partly described peculiarities of spatial variability of observed thawing depths.</p>

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