Results 51 to 60 of about 568 (186)

On the Origin of Summer Sporadic E Periodicities at Midlatitudes

Space Weather, Volume 24, Issue 9, September 2026.
Abstract Summertime midlatitude sporadic E (Es) layers exhibit daily periodicities whose underlying physical causes remain to be fully identified. We investigate the origin of these periodicities by analyzing an 11‐year data set (2007–2017) comprising ionosonde measurements, FORMOSAT‐3/COSMIC radio occultation (RO) observations, and WACCM‐X neutral ...
Xu Yan, Hongtao Cai, Yusong Qin, Chao Xiong, Jiawei Zhou, Hongwen Xu, Lubing Yang   +6 more
wiley   +1 more source

On the Determination of Velocities of Radar Meteors [PDF]

International Astronomical Union Colloquium, 1996
AbstractThe results of testing the classical method of velocity determination based on the positions of the extrema of Fresnel diffraction patterns (FDP) in radio echo amplitude, is presented. This technique is compared to the method of nonlinear least squares fitting (NLSF) of the theoretical patterns to the observed those.
openaire   +1 more source

HF Heating Effects as Seen From Below and Above: First Results of Joint SURA–Ionosfera‐M Experiment

Geophysical Research Letters, Volume 53, Issue 16, 28 August 2026.
Abstract This paper presents the first results of a coordinated experiment on the ionospheric plasma response to high‐frequency (HF) overdense heating, conducted using the SURA heating facility and the Ionosfera‐M satellite. The experiment combined ground‐based observations with in situ satellite measurements, enabling a comprehensive study of ...
A. A. Chernyshov, A. M. Padokhin, S. M. Grach, D. A. Kogogin, A. V. Shindin, S. A. Pulinets, I. A. Nasyrov, A. B. Beletsky, I. D. Tkachev, J. K. Legostaeva, D. V. Chugunin, M. A. Evdokimova, G. A. Kurbatov, K. G. Tsybulya, A. E. Solin, A. V. Shchennikov, E. V. Tareeva, V. V. Emelyanov, M. M. Mogilevsky   +18 more
wiley   +1 more source

On the validity of the ambipolar diffusion assumption in the polar mesopause region [PDF]

Annales Geophysicae, 2008
The decay of underdense meteor trails in the polar mesopause region is thought to be predominantly due to ambipolar diffusion, a process governed by the ambient temperature and pressure.
A. P. Ballinger, P. B. Chilson, R. D. Palmer, N. J. Mitchell   +3 more
doaj   +1 more source

An Integrated Process‐Based Approach for Interpreting Precipitation Isotopes Using North‐Central Texas as a Testbed

Journal of Geophysical Research: Atmospheres, Volume 131, Issue 16, 28 August 2026.
Abstract The isotopic composition of precipitation reflects the combined influences of moisture sources, rainout history, and convective intensity, but the relative importance of these controls varies among regions and remains poorly understood in continental settings.
Juan Camacho‐Puerto, Ricardo Sánchez‐Murillo   +1 more
wiley   +1 more source

Determination of meteor-head echo trajectories using the interferometric capabilities of MAARSY [PDF]

Annales Geophysicae, 2013
During the flight of a meteoroid through the neutral atmosphere, the high kinetic energy is sufficient to ionize the meteoric constituents. Radar echoes coming from plasma irregularities surrounding the meteoroids are called meteor-head echoes, and ...
C. Schult, G. Stober, J. L. Chau, R. Latteck   +3 more
doaj   +1 more source

Anomalies and Recovery of Evaporation Ducts Induced by Typhoons in the Northwest Pacific

Geophysical Research Letters, Volume 53, Issue 15, 16 August 2026.
Abstract Despite widespread attention on tropical cyclone (TC)‐induced cold wakes, the dynamic recovery of evaporation duct height (EDH) post‐typhoon remains unclear. Using ERA5 data from 338 Northwestern Pacific TCs (2003–2023), we quantify the spatiotemporal evolution of EDH after TC passage.
Xuhang Li, Xiaoping Cheng, Jiayuan Zhang, Jianfang Fei, Xiaogang Huang   +4 more
wiley   +1 more source

The ORCA‐TWIN qCMOS Experiment I. Science Case and Commissioning at Calar Alto Observatory

Astronomische Nachrichten, Volume 347, Issue 7, August 2026.
ABSTRACT We describe a pilot study to explore a new generation of fast and low noise CMOS image sensors for time domain astronomy, using two remote telescopes with a baseline of 1635 km. The experiment involves direct imaging with novel qCMOS image sensor technology that combines fast readout with sub‐electron readout noise.
Martin M. Roth, Paško Roje, Stella Vješnica, Stefan Cikota, Alex J. Brown, Mike Kretlow, Marco Azzaro, Santiago Reinhart, Jesús Aceituno, Harry Dawson, Carsten Denker, Torsten Enßlin, Stephan Geier, Thomas Granzer, Thomas Kupfer, Gianluca Li Causi, Samaya Nissanke, José Luis Ortiz, Fernando Pedichini, Katja Poppenhäger, Axel Schwope   +20 more
wiley   +1 more source

Global variation of meteor trail plasma turbulence [PDF]

Annales Geophysicae, 2011
We present the first global simulations on the occurrence of meteor trail plasma irregularities. These results seek to answer the following questions: when a meteoroid disintegrates in the atmosphere, will the resulting trail become plasma turbulent ...
L. P. Dyrud, J. Urbina, J. T. Fentzke, E. Hibbit, J. Hinrichs   +4 more
doaj   +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