Muhammad Mubasshir Shaikh , Manar Anwer Khaleel Abusirdaneh
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引用次数: 0
Abstract
Understanding the variable behavior of the IDL/Es system contributes significantly to our ability in characterizing and modeling the critical ionospheric dynamics across the globe. In this work we aim to improve the understanding of the IDL/Es system by analyzing the diurnal and seasonal variations in the altitude descent with reference to local time of the day, season, and solar activity. We apply the well-known height-time-intensity analysis method on measurements obtained from the Sharjah ionosonde station, located at the Arabian Peninsula (Sharjah: 25.28°N, 55.46°E) near the northern crest of the equatorial ionization anomaly. The measurements cover three years of the increasing phase of the solar cycle 25 from 2020 to 2022. Considering an oversimplified wind system based on windshear theory, we attempt to establish a relationship between IDL/Es periodicities with diurnal, semidiurnal, and terdiurnal tides without digging into the underlying mechanism. Results suggest a strong relation between semidiurnal and terdiurnal tides and the formation and transport of the IDL, particularly impacting lower E-region and sporadic-E layers during the afternoon and nighttime hours. The results of manual scaling of over eleven thousand ionograms is presented to quantify the behavior of the IDL/Es system's transport. Additionally, a connection between solar activity, descent rate, and initial descending height, with semidiurnal patterns consistently present across seasons and solar activity has been discussed. For different frequency bins used in this work, e.g. 3 MHz, 4 MHz, and 5 MHz, seasonal variations significantly influence descent patterns.
期刊介绍:
The Journal of Atmospheric and Solar-Terrestrial Physics (JASTP) is an international journal concerned with the inter-disciplinary science of the Earth''s atmospheric and space environment, especially the highly varied and highly variable physical phenomena that occur in this natural laboratory and the processes that couple them.
The journal covers the physical processes operating in the troposphere, stratosphere, mesosphere, thermosphere, ionosphere, magnetosphere, the Sun, interplanetary medium, and heliosphere. Phenomena occurring in other "spheres", solar influences on climate, and supporting laboratory measurements are also considered. The journal deals especially with the coupling between the different regions.
Solar flares, coronal mass ejections, and other energetic events on the Sun create interesting and important perturbations in the near-Earth space environment. The physics of such "space weather" is central to the Journal of Atmospheric and Solar-Terrestrial Physics and the journal welcomes papers that lead in the direction of a predictive understanding of the coupled system. Regarding the upper atmosphere, the subjects of aeronomy, geomagnetism and geoelectricity, auroral phenomena, radio wave propagation, and plasma instabilities, are examples within the broad field of solar-terrestrial physics which emphasise the energy exchange between the solar wind, the magnetospheric and ionospheric plasmas, and the neutral gas. In the lower atmosphere, topics covered range from mesoscale to global scale dynamics, to atmospheric electricity, lightning and its effects, and to anthropogenic changes.