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The Temperature versus Altitude Graph of Earth's Atmosphere.
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Before the discovery of ionosphere, the electronic communication was not possible at a distance greater than 100 km due to the curvature of Earth; but after its discovery, the ionospheric wave propagation made possible the electronic communication at even more than 3000 km via reflection of radio waves through ionosphere. The ionosphere is electric...
Context in source publication
Context 1
... Earth's atmosphere is divided into different layers based on temperature and compositional changes in the chemistry of gases. These atmospheric layers are troposphere, stratosphere, mesosphere, thermosphere and exosphere ( Figure 1). The troposphere extends up to 12 km from Earth's surface, stratosphere from 12 to 50 km, mesosphere from 50 to 80 km, thermosphere from 80 to 700 km and exosphere from 700 km to outer space around 10,000 km. ...
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In order to reveal solar activity dependence of the medium-scale traveling ionospheric disturbances (MSTIDs) at midlatitudes, total electron content (TEC) data obtained from a Global Positioning System (GPS) receiver network in Japan during 22 years from 1998 to 2019 were analyzed. We have calculated the detrended TEC by subtracting the 1-h running...
Citations
... The ionosphere, situated in the upper atmosphere of Earth, plays a vital role in various phenomena such as radio wave propagation, satellite communication, and space weather dynamics [1][2][3][4][5]. Among its layers, the F2-layer holds particular significance in long-distance radio communication. ...
The research examines ionospheric F2-layer virtual height (h'F2) variations at Ilorin (14.80°N, 17.40°W) in the Africa sector and Boa Vista (2.80°N, 299.30°E) in the America sector, during Solar Cycle 25's minimum and ascending phases. The aim is to investigate the temporal and spatial variations of the virtual height of the F2-layer over two equatorial stations during the minimum to ascending phase of Solar Cycle 25 at two equatorial stations in two different longitudinal sectors. Analyzing data from these stations statistically, the paper investigates diurnal, seasonal, and annual variations in h'F2.Diurnally, the h'F2 demonstrates greater responsiveness during daytime (06:00-18:00 LT) compared to nighttime (18:00-05:00 LT). Seasonally, peak values occur around noon and post-noon periods, displaying significant disparities during equinoxes and solstices over both stations in the different solar phases. During the minimum phase year (2020), peak heights of h'F2 reached 387 km at Ilorin and 372 km at Boa Vista. In the ascending phase year (2021), these peaks slightly shifted to 389 km at Ilorin and 404 km at Boa Vista. Annually, the highest peak values of h'F2 occur at noon, measuring 376 km at Ilorin and 331 km at Boa Vista during the minimum phase, while during the ascending phase, both stations recorded almost identical values of 305 km at noon. Overall, h'F2 variation exhibited higher magnitude at Ilorin in the African longitudinal sector than at Boa Vista in the American longitudinal sector during the minimum phase of solar cycle 25, with the reverse observed during the ascending phase. This detailed analysis illuminates the complex variations in ionospheric behavior across various time frames and geographic locations, showcasing substantial variability and sensitivity to solar influences in equatorial stations across Africa and America.
... The ionosphere, situated in the upper atmosphere of Earth, plays a vital role in various phenomena such as radio wave propagation, satellite communication, and space weather dynamics [1][2][3][4][5]. Among its layers, the F2-layer holds particular significance in long-distance radio communication. ...
The research examines ionospheric F2-layer virtual height (h'F2) variations at Ilorin (14.80°N, 17.40°W) in the Africa sector and Boa Vista (2.80°N, 299.30°E) in the America sector, during Solar Cycle 25's minimum and ascending phases. The aim is to investigate the temporal and spatial variations of the virtual height of the F2-layer over two equatorial stations during the minimum to ascending phase of Solar Cycle 25 at two equatorial stations in two different longitudinal sectors. Analyzing data from these stations statistically, the paper investigates diurnal, seasonal, and annual variations in h'F2.Diurnally, the h'F2 demonstrates greater responsiveness during daytime (06:00-18:00 LT) compared to nighttime (18:00-05:00 LT). Seasonally, peak values occur around noon and post-noon periods, displaying significant disparities during equinoxes and solstices over both stations in the different solar phases. During the minimum phase year (2020), peak heights of h'F2 reached 387 km at Ilorin and 372 km at Boa Vista. In the ascending phase year (2021), these peaks slightly shifted to 389 km at Ilorin and 404 km at Boa Vista. Annually, the highest peak values of h'F2 occur at noon, measuring 376 km at Ilorin and 331 km at Boa Vista during the minimum phase, while during the ascending phase, both stations recorded almost identical values of 305 km at noon. Overall, h'F2 variation exhibited higher magnitude at Ilorin in the African longitudinal sector than at Boa Vista in the American longitudinal sector during the minimum phase of solar cycle 25, with the reverse observed during the ascending phase. This detailed analysis illuminates the complex variations in ionospheric behavior across various time frames and geographic locations, showcasing substantial variability and sensitivity to solar influences in equatorial stations across Africa and America.
We report the estimation of the Maximum Usable Frequency of F2-layer for 3000 km circuit (MUF(3000)F2) using Earth-ionosphere geometry. The study is based on the assumption that h′F2 may replace hmF2 to estimate M(3000)F2. The monthly hourly medians of foF2,h′F2, and M(3000)F2 are extracted for Karachi (geog. coord. 24.9° N, 67.3° E) & Multan (30.2° N, 71.5° E) during 1996, 1992, & 1989 representing low, moderate & high solar activity years, respectively. The MUF(3000)F2 estimated using spherical geometry shows large deviation and greater Root Mean Square Error values (RMSE > 4 MHz) on comparison with MUF(3000)F2 observed from ionosonde. In order to reduce the error, linear regression analysis technique is used and applied on independent data set of years 1995, 1993 and 1991 representing low, moderate and high solar activity to compute corrected MUF(3000)F2, respectively. It is found that corrected MUF is in good agreement with observed MUF decreasing RMSE to less than 2.0 MHz for the stations and years under study. The results of this study would be helpful in MUF estimation using h′F2 and also in improving radio services for smooth HF communication.
