Results 31 to 40 of about 993 (181)

On the Generation of Pre‐Sunrise Equatorial Plasma Bubbles in Southeast Asia During the Geomagnetic Storm of May 2024

Earth and Space Science, Volume 13, Issue 8, August 2026.
Abstract A set of fresh Equatorial Plasma Bubbles (EPBs) formed during pre‐sunrise hours in the Southeast Asian sector amid the recovery phase of May 2024 geomagnetic storm. They offered new insights into their formation mechanism. This study used Total Electron Content (TEC) and Rate of TEC Index maps over Indonesia, along with ionosondes in Thailand ...
Sri Ekawati, Prayitno Abadi, Takuya Sori, Rezy Pradipta, Ihsan Naufal Muafiry, Teguh Nugraha Pratama, Agri Faturahman, Noersomadi, Febrylian Fahmi Chabibi, Punyawi Jamjareegulgarn   +9 more
wiley   +1 more source

Signal Data Stream Parameters Passing Ionospheric Communication Links With Fading Caused by Natural Clutter Phenomena

Radio Science, Volume 61, Issue 8, August 2026.
Abstract This paper explores the impact of natural phenomena on signal data transmission across various ionospheric communication channels. The study focuses on three primary phenomena: meteor trails prevalent in the middle‐ and lower‐latitude ionosphere, bubble and plume structures observed around the equatorial ionosphere, and magnetic‐storm‐induced ...
I. Bronfman, Y. Ben‐Shimol, N. Blaunstein   +2 more
wiley   +1 more source

Observations of ionospheric disturbances via U-shaped traces on ionograms

Геодинамика и тектонофизика, 2019
The ionospheric vertical sounding is a basic technique for studying the Earth’s ionosphere. Taking into account the fact that conditions for propagation of radio waves depend on the operating frequency, diagnostics of the ionosphere is performed using ...
O. A. Laryunin
doaj   +1 more source

Physics‐Embedded Deep Learning Reveals the Memory Effect of Ionospheric Electron Density in Response to Solar EUV Forcing

Geophysical Research Letters, Volume 53, Issue 14, 28 July 2026.
Abstract Precise characterization of the electron density profile is crucial for optimizing high frequency communications. Reconstruction models often assume an instantaneous ionospheric response to solar forcing or using time delays, neglecting the time‐integrated cumulative “memory effect” of plasma dynamics.
Hongwei Gong, Hanxian Fang, Die Duan, Chao Xiao, Jintai Li, Chenghao Li, Hongtao Huang, Ganming Ren, Chuyue Zhou, Han Wu   +9 more
wiley   +1 more source

Modeling z-shaped disturbance along the Pedersen ray of oblique sounding ionogram using adaptation of IRI to experimental data

Solar-Terrestrial Physics, 2016
We present the results of numerical modeling of a traveling ionospheric disturbance that causes z-shaped bends at the Pedersen ray of oblique incidence ionograms.
Kim A.G., Ponomarchuk S.N., Kotovich G.V., Romanova E.B.   +3 more
doaj   +1 more source

AMPLITUDE VARIATIONS OF THE REFLECTED SIGNAL DURING VERTICAL SOUNDING OF THE IONOSPHERE AT MIDDLE LATITUDES

Solar-Terrestrial Physics, 2020
In this paper, we discuss the main types of quasiperiodic variations in amplitudes of a reflected signal during vertical sounding of the ionosphere at middle latitudes.
K.М. Yusupov, J.D. Mathews, T. Maruyama, A.D. Akchurin, M.V. Tolstikov, O.N. Sherstyukov, E.A. Filippova, A.S. Safiullin   +7 more
doaj   +1 more source

Image processing of digital chest ionograms

The British Journal of Radiology, 1988
Abstract A number of image-processing techniques have been applied to a digital ionographic chest image in order to evaluate their possible effects on this type of image. In order to quantify any effect, a simulated lesion was superimposed on the image at a variety of locations representing different types of structural detail ...
J R, Yarwood, B M, Moores
openaire   +2 more sources

ROSE: a high performance oblique ionosonde providing new opportunities for ionospheric research

Annals of Geophysics, 1994
A high quality high frequency (HF) oblique ionosonde has been developed for use in propagation research and associated studies of the ionosphere. The ionosonde is known as ROSE (radio oblique sounding equipment) and requires the connection of a specially
P. S. Cannon, P. C. Arthur
doaj   +1 more source

When a Bulbar Ulcer Hides a Darker Reality: The Unusual Diagnosis of a Portal Cavernoma in a 69‐Year‐Old Adult

Clinical Case Reports, Volume 14, Issue 7, July 2026.
ABSTRACT A portal cavernoma is a network formed by localized dilation of the hepatic portal system. This study aims to describe a case of portal cavernoma in a 69‐year‐old adult presenting with gastrointestinal hemorrhage. This is a 69‐year‐old patient with no particular medical history admitted for hematemesis associated with diffuse abdominal pain ...
Martin Wendlassida Nacanabo, André Arthur Taryètba Seghda, Aimé Arsène Yaméogo, Ella Hatoula Lengani, Adolphe Benjamin Zingué Ouattara, Aminata Guiarra, Yannick Laurent Tchenadoyo Bayala, Abdoul Nassir Porgo, Abdoul Aziz, Abdoul Djalilou Traoré, Anna Tall/Thiam, Georges Christian Millogo, Valentin Nobila Yaméogo, André Koudnoaga Samadoulougou   +13 more
wiley   +1 more source

Optimizing HAARP Beam Pattern for Generation of Strong F‐Region Field‐Aligned Irregularities

Radio Science, Volume 61, Issue 7, July 2026.
Abstract Field‐aligned irregularities (FAIs) are the signatures of plasma turbulence and convection in the mid‐ and high‐latitude F‐region ionosphere, and also provide coherent backscatter targets for HF radars. To serve irregularity generation and characterization studies, we conducted experiments at the High‐frequency Active Auroral Research Program (
T. S. Anderson, E. H. Lay, I. T. Cummings, C. A. Jeffery, P. A. Bernhardt, M. McCarrick, W. A. Bristow, S. J. Briczinski   +7 more
wiley   +1 more source