Results 21 to 30 of about 83 (58)

Formation of the Ionospheric G‐Condition Following the 2017 Great American Eclipse

Earth and Space Science, Volume 12, Issue 8, August 2025.
Abstract A total solar eclipse (TSE) traversed the continental US (CONUS) from west to east on 21 August 2017. Ionosondes located under the eclipse totality at Lusk (Wyoming) and Boulder (Colorado) observed the ionospheric G‐condition 20 min after totality.
S. Chakraborty, L. Qian, S. Mrak, J. Mabie, L. Goncharenko, J. M. Mclnerney, T. Bullett   +6 more
wiley   +1 more source

Direct Observation of Quasi‐Monochromatic Gravity Wave Packets Associated With the Polar Night Jet Using a Doppler‐Rayleigh Lidar

Journal of Geophysical Research: Atmospheres, Volume 130, Issue 14, 28 July 2025.
Abstract An advanced hodograph technique was applied to extract quasi‐monochromatic, linear gravity wave (GW) packets from simultaneous wind and temperature measurements made using a ground‐based Doppler‐Rayleigh‐Mie‐Raman lidar located in Kühlungsborn (54°N, 12°E).
Robin Wing, Irina Strelnikova, Andreas Dörnbrack, Michael Gerding, Eframir Franco‐Diaz, Laura Holt, Mohamed Mossad, Gerd Baumgarten   +7 more
wiley   +1 more source

Evolution of Post‐Sunset EPBs: Relationships to the EIA Induced by Pre‐Reversal Enhancement Electric Fields

Space Weather, Volume 23, Issue 7, July 2025.
Abstract This paper presents Global Navigation Satellite System radio occultation (RO) observational analyses on deducing the relationships and dependences between post‐sunset equatorial plasma bubbles (EPB) occurrences and equatorial ionospheric anomaly (EIA) strength variability.
Lung‐Chih Tsai, Shin‐Yi Su, Harald Schuh, Mohamad Mahdi Alizadeh, Jens Wickert   +4 more
wiley   +1 more source

Indian Equatorial Ionosphere Under the Influence of the May 2024 Geomagnetic Storm: Insights Into Electric Fields, Plasma Irregularities and F‐Region Dynamics

Earth and Space Science, Volume 12, Issue 5, May 2025.
Abstract This study investigates the distinctive features of the daytime equatorial E‐region ionosphere using observations of HF radar (18 MHz), ionosonde, and magnetometer at Thumba (8.5°N, 77°E, dip lat = 1.9°N), India, during the extreme geomagnetic storm of May 10–11, 2024 (minimum SYM‐H ∼ −497 nT).
Lalitha G. Krishnan, Tarun Kumar Pant, T. Manu, C. Vineeth, Lijo Jose, Reuben Samson Yaqub, K. S. Vishnupriya, T. V. Sruthi   +7 more
wiley   +1 more source

The Propagation and Evolution of Polar Cap Patches During Auroral Substorm Activity

Journal of Geophysical Research: Space Physics, Volume 130, Issue 5, May 2025.
Abstract Polar cap patches are islands of enhanced plasma density formed during intervals of southward interplanetary magnetic field (IMF). The present study examines the observations of polar cap patches during sequential auroral substorms that occurred on 9 September 2011.
Jianjun Liu, Yaqi Jin, Xiangcai Chen, Zhiwei Wang, Fang He, Zejun Hu, Akira Sessai Yukimatu, William Bristow, Hongqiao Hu, Beichen Zhang   +9 more
wiley   +1 more source

Generalized Force Method for Point‐To‐Point Ray Tracing in Anisotropic Ionosphere: Implementation and Applications to NeQuick2 and IGRF13 Models

Radio Science, Volume 60, Issue 3, March 2025.
Abstract The generalized force method, previously developed for an isotropic inhomogeneous ionosphere, exploits the knowledge about the character of the extrema of the phase distance—where high ionospheric rays correspond to minima and low rays to saddle points—to systematically find all relevant rays between fixed points, thereby enabling efficient ...
I. A. Nosikov, M. V. Klimenko, A. M. Padokhin, V. V. Nosikova, P. F. Bessarab   +4 more
wiley   +1 more source

Application of SuperDARN Interferometry for Improved Estimates of Doppler Velocity and Echo Geolocation

Radio Science, Volume 60, Issue 1, January 2025.
Abstract It has been previously established that the Doppler velocities of F‐region ionospheric echoes observed by the Super Dual Auroral Radar Network (SuperDARN) at high frequencies (HF, 8–20 MHz) are persistently lower than those measured by other instruments at the same locations. This was attributed to the ionospheric refractive index for HF radio
P. Ponomarenko, M. Ghalamkarian Nejad, A. V. Koustov   +2 more
wiley   +1 more source

An HF sweep frequency study of the arctic ionosphere [PDF]

, 1961
Observations made during 1958 and 1959 using a sweep frequency, HF, oblique sounder located at College, Alaska, are discussed, and selected groups of echoes are illustrated.
Bates, Howard F.
core  

Multi‐Frequency SuperDARN HF Radar Observations of the Ionospheric Response to the October 2023 Annular Solar Eclipse

Geophysical Research Letters, Volume 51, Issue 24, 28 December 2024.
Abstract An annular solar eclipse was visible on 14 October 2023 from 15:00–21:00 UT as its path traveled across North, Central, and South America. In this letter, we present the first multi‐frequency Super Dual Auroral Radar Network (SuperDARN) observations of the bottomside ionospheric response to a solar eclipse using a novel experimental mode ...
E. G. Thomas, S. G. Shepherd, B. S. R. Kunduri, D. R. Themens   +3 more
wiley   +1 more source

On the Growth and Evolution of Nocturnal Ionospheric Irregularities Using HF Radar Observations Along With Digisonde and GNSS Data Over Trivandrum, India

Space Weather, Volume 22, Issue 11, November 2024.
Abstract The growth and evolution of nocturnal ionospheric plasma irregularities are analyzed over the geomagnetic equatorial station Trivandrum (8.5°N, 77°E, dip latitude 1.9°N) using multi‐instrumental techniques during various seasons of moderate and high solar activity periods.
T. V. Sruthi, G. Manju
wiley   +1 more source