SOLAR TERMINATOR AND IONOSPHERIC PROPAGATION OF RADIO WAVES

2021 ◽  
pp. 15-23
Author(s):  
V. M. Somsikov ◽  
I. P. Chunchuzov ◽  
A. Jahanshir ◽  
S. N. Mukasheva
Keyword(s):  
Temperature Gradient ◽  
Solar Radiation ◽  
Multipath Propagation ◽  
Experimental Studies ◽  
Radio Waves ◽  
Regular Source ◽  
Entire Thickness ◽  
Phase Variations ◽  
Solar Terminator ◽  
The Difference

The paper provides a review of studies devoted to the peculiarities of the propagation of radio waves in the ionosphere in the area of the solar terminator, which is the only global and regular source of acoustic-gravitational waves and other disturbances of the ionosphere. It describes the results of theoretical works devoted to the study of perturbations created by the solar terminator in the area of the difference in the intensity of solar radiation in the atmosphere. The paper gives a review of experimental studies of the effects created by the solar terminator in the entire thickness of the atmosphere. These effects, in particular, include the multipath propagation of radio waves, their phase variations, and variations in amplitudes during the propagation of radio waves in the area of the solar terminator. In the interests of science and practice, a number of problems have been proposed for the further study of wave perturbations arising as a result of the movement of the temperature gradient at sunrise and sunset hours.

scholarly journals Investigation of the parameters of traveling ionospheric disturbances using a chirp ionosonde

2021 ◽  
Vol 2131 (5) ◽  
pp. 052097
Author(s):  
F Vybornov
Keyword(s):  
Multipath Propagation ◽  
Experimental Studies ◽  
Vertical Motion ◽  
Ionospheric Disturbances ◽  
Radio Waves ◽  
Technical Parameters ◽  
Traveling Ionospheric Disturbances ◽  
The Village ◽  
The City ◽  
Nizhny Novgorod Region

Abstract This article presents the results of experimental studies of parameters of natural traveling ionospheric disturbances of “sickle” type observed at mid-latitudes using linear frequency modulation ionosondes. Technical parameters of the ionosondes used are given. Experiments were carried out on slightly inclined paths in the central part of Russia in 2015 - 2020 in the daytime. The transmitting station was located in the village of Vasilsursk, Nizhny Novgorod Region. Registration was carried out in the city of Nizhny Novgorod. Examples of ionograms obtained in the course of measurements with different structure of perturbations are given. Estimates of development times of disturbances and their frequency range have been made. The structure of the received signal is analyzed. Based on the results of a complex experiment using a network of synchronously operating ionosondes of the same type, the data obtained were analyzed and direction and magnitude of propagation velocity of the phase front of moving disturbance were determined. A possible mechanism for the imitation of one-way vertical motion of a traveling disturbance characteristic of the mid-latitude ionosphere is discussed within the framework of multipath propagation of radio waves.

scholarly journals The role of L/W in the solar radiation for Saharian cities

2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Energy Levels ◽  
Direct Solar Radiation ◽  
Test Field ◽  
Natural Lighting ◽  
The Difference ◽  
The Impact ◽  
The Relationship

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.

scholarly journals IDENTIFICATION AND MODELLING PROCESS OF DEFINING TEMPERATURE GRADIENT IN AIRPORT PAVEMENT

Aviation ◽  
2014 ◽  
Vol 18 (2) ◽  
pp. 72-79
Author(s):  
Ervina Ahyudanari ◽  
Nasir Shafiq ◽  
Ibrahim Kamaruddin
Keyword(s):  
Temperature Gradient ◽  
Solar Radiation ◽  
Cyclic Load ◽  
Gap Analysis ◽  
Load Path ◽  
Construction Design ◽  
Airport Pavement ◽  
Pavement Temperature ◽  
Pavement Structures ◽  
Safety Operation

Preserving airport pavement means guarantying the safety operation of aircraft movements. There are four aspects that cause progressive pavement deterioration, i.e. the construction design and process, selected material, and maintenance management. One of the traffic aspects, jet engine exhaust, has not been discovered yet. The load pattern of the jet exhaust follows the schedule of aircraft traffic. The assumption held in this research is that the thermal load during aircraft movement may generate a high temperature, which is induced into pavement layers. The objective of this research is to determine the temperature gradient in the pavement, caused by the jet exhaust. This paper discusses the process of determining the temperature gradient in four stages, i.e. by carrying out the gap analysis, evaluation of pavement structures, determination of the load path and the magnitude, and defining the temperature gradient. The temperature gradient in the pavement layer is determined through the development of a model of cyclic loading. The thermal cyclic load follows the aircraft schedule pattern. The pavement temperature receives the thermal cyclic load of the sinusoid of solar radiation. The results indicate that the temperature of the pavement is increased and pavement temperature rises by 35 °C. However, after 60 seconds the remaining temperature of the pavement layer decreases to the initial temperature, which is caused by solar radiation.

Investigation of Regression-Based Effect Size Methods Developed in Single-Subject Studies

2021 ◽  
pp. 014544552110540
Author(s):  
Nihal Sen
Keyword(s):  
Effect Size ◽  
Experimental Studies ◽  
Single Subject ◽  
Single Subject Design ◽  
Data Set ◽  
Design Studies ◽  
Sample Data ◽  
The Difference ◽  
D Values ◽  
Effect Size Calculation

The purpose of this study is to provide a brief introduction to effect size calculation in single-subject design studies, including a description of nonparametric and regression-based effect sizes. We then focus the rest of the tutorial on common regression-based methods used to calculate effect size in single-subject experimental studies. We start by first describing the difference between five regression-based methods (Gorsuch, White et al., Center et al., Allison and Gorman, Huitema and McKean). This is followed by an example using the five regression-based effect size methods and a demonstration how these methods can be applied using a sample data set. In this way, the question of how the values obtained from different effect size methods differ was answered. The specific regression models used in these five regression-based methods and how these models can be obtained from the SPSS program were shown. R2 values obtained from these five methods were converted to Cohen’s d value and compared in this study. The d values obtained from the same data set were estimated as 0.003, 0.357, 2.180, 3.470, and 2.108 for the Allison and Gorman, Gorsuch, White et al., Center et al., as well as for Huitema and McKean methods, respectively. A brief description of selected statistical programs available to conduct regression-based methods was given.

Solar Radiation and Earth Temperatures

1902 ◽  
Vol 23 ◽  
pp. 296-311
Author(s):  
C. G. Knott
Keyword(s):  
Solar Radiation ◽  
Direct Effect ◽  
Recent Meeting ◽  
The Mediterranean ◽  
The Difference

At a recent meeting of the Society, Dr Buchan read a paper based on certain observations of the temperature of the waters of the Mediterranean, which had been made by the staff of the Austrian ship Pola. These indicated that the direct effect of solar Tadiation was felt to a depth of over 150 feet. At any rate, the facts were that the temperature of the upper stratum of water of this thickness was perceptibly higher at about 4 p.m. than at 8 a.m., and that the difference was about 1°·5 Fahr. or 0°·8 Cent, at the surface, diminishing fairly steadily to value zero at a depth of fully 150 feet or 50 metres. It may easily be calculated that this excess of temperature at the afternoon hour means the accumulation of an amount of heat equal to 1460 units in every column of water 1 square centimetre in section; and this is accomplished within the eight hours from 8 a.m. to 4 p.m. It must be noted that this accumulation of heat is a daily occurrence.

scholarly journals The influence of observed and modelled net longwave radiation on the rate of estimated potential evapotranspiration

2019 ◽  
Vol 67 (3) ◽  
pp. 280-288 ◽  
Author(s):  
Jitka Kofroňová ◽  
Miroslav Tesař ◽  
Václav Šípek
Keyword(s):  
Czech Republic ◽  
Solar Radiation ◽  
Potential Evapotranspiration ◽  
Sunshine Duration ◽  
Longwave Radiation ◽  
Radiation Balance ◽  
Parameter Calibration ◽  
Atmospheric Emissivity ◽  
The Bohemian Forest ◽  
The Difference

Abstract Longwave radiation, as part of the radiation balance, is one of the factors needed to estimate potential evapotranspiration (PET). Since the longwave radiation balance is rarely measured, many computational methods have been designed. In this study, we report on the difference between the observed longwave radiation balance and modelling results obtained using the two main procedures outlined in FAO24 (relying on the measured sunshine duration) and FAO56 (based on the measured solar radiation) manuals. The performance of these equations was evaluated in the April–October period over eight years at the Liz experimental catchment and grass surface in the Bohemian Forest (Czech Republic). The coefficients of both methods, which describe the influence of cloudiness factor and atmospheric emissivity of the air, were calibrated. The Penman-Monteith method was used to calculate the PET. The use of default coefficient values gave errors of 40–100 mm (FAO56) and 0–20 mm (FAO24) for the seasonal PET estimates (the PET was usually overestimated). Parameter calibration decreased the FAO56 error to less than 20 mm per season (FAO24 remained unaffected by the calibration). The FAO56 approach with calibrated coefficients proved to be more suitable for estimation of the longwave radiation balance.

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