Results 41 to 50 of about 859 (172)

The Turbulence Properties of 150‐km Echoes in the Lower Ionosphere

Geophysical Research Letters, Volume 53, Issue 12, 28 June 2026.
Abstract The valley region ionosphere spans from approximately 120–200 km in altitude, and hosts a wide range of plasma, neutral, and solar interactions that create and maintain the ionosphere. In this region a ubiquitous and mysterious source of radar echoes called “150‐km echoes” has been observed since the 1960s.
William J. Longley, Lindsay V. Goodwin, Chirag R. Skolar, Nicholas M. Pedatella   +3 more
wiley   +1 more source

Direct Observation of the M1 Transition between the Ground Term Fine Structure Levels of W VIII

Atoms, 2017
We present a direct observation of the M1 transition between the fine structure splitting in the 4 f 13 5 s 2 5 p 6 2 F ground term of W VIII. The spectroscopic data of few-times ionized tungsten ions are important for the future
Momoe Mita, Hiroyuki A. Sakaue, Daiji Kato, Izumi Murakami, Nobuyuki Nakamura   +4 more
doaj   +1 more source

Plasma‐Sequence‐Engineered Atomic Layer Deposition of Ultra‐Thin SiNx for Enhanced Etching Resistance in Extreme Ultraviolet Pellicles

Advanced Materials Interfaces, Volume 13, Issue 11, 9 June 2026.
Plasma‐sequence‐engineered ALD (PSE‐ALD), based on sequential NH3 and N2 plasma pulses, enables ultrathin, dense SiNx films. ToF‐MS analysis confirms ligand removal via HCl evolution, while increased film density indicates network densification. The resulting SiNx coating provides robust protection of graphite under H2 plasma exposure.
Hye‐Young Kim, Sung Kyu Jang, Jihun Kim, Jong‐Hyun Choi, Ji‐Beom Yoo, Hyun‐Mi Kim, Seul‐Gi Kim, Hyeongkeun Kim   +7 more
wiley   +1 more source

Statistical analysis for EUV dynamic spectra and their impact on the ionosphere during solar flares

Earth, Planets and Space, 2023
The X-rays and extreme ultraviolet (EUV) emitted during solar flares can rapidly change the physical composition of Earth’s ionosphere, causing space weather phenomena.
Shohei Nishimoto, Kyoko Watanabe, Hidekatsu Jin, Toshiki Kawai, Shinsuke Imada, Tomoko Kawate, Yuichi Otsuka, Atsuki Shinbori, Takuya Tsugawa, Michi Nishioka   +9 more
doaj   +1 more source

Ionosphere‐Thermosphere Responses to the March 2023 Geomagnetic Storm Using Observations and TIEGCM Simulations Driven by Data Assimilated Aurora and Electric Fields

Journal of Geophysical Research: Space Physics, Volume 131, Issue 6, June 2026.
Abstract We investigate Ionosphere‐Thermosphere (IT) responses to the March 2023 geomagnetic storm using GOLD and PFISR observations, along with TIEGCM simulations driven by data‐assimilated aurora and electric fields. A Lattice Kriging approach is implemented to assimilate auroral electron flux and characteristic energy from ground‐based (THEMIS/ASIs)
Prakash Poudel, Xian Lu
wiley   +1 more source

Multiwavelength Sun-as-a-star Analysis of the M8.7 Flare on 2022 October 2 Using Hα and EUV Spectra Taken by SMART/SDDI and SDO/EVE

The Astrophysical Journal
This paper presents a multiwavelength Sun-as-a-star analysis of the M8.7 flare on 2022 October 2, which was associated with a filament eruption and the subsequent coronal mass ejection.
Takato Otsu, Ayumi Asai
doaj   +1 more source

Spectra of Ga-Like to Cu-Like Praseodymium and Neodymium Ions Observed in the Large Helical Device

Atoms, 2021
Extreme ultraviolet (EUV) spectra of highly charged praseodymium (Pr) and neodymium (Nd) ions have been investigated in optically thin high-temperature plasmas produced in the Large Helical Device (LHD), a magnetically confined torus device for fusion ...
Chihiro Suzuki, Fumihiro Koike, Izumi Murakami, Tetsutarou Oishi, Naoki Tamura   +4 more
doaj   +1 more source

Identifying and Predicting Coronal Mass Ejection Occurrence: Observational Checklists for Space Weather Forecasters

Space Weather, Volume 24, Issue 6, June 2026.
Abstract Ejections of magnetized plasma from the Sun, known as coronal mass ejections, can drive major geomagnetic activity if Earth‐directed, and are therefore monitored by space weather forecasters. The current focus being the forecast of the arrival time of a coronal mass ejection at Earth and the level of geomagnetic impact.
L. M. Green, A. W. James, N. Ngampoopun, S. L. Yardley, K. Waite, E. K. Mottram, J. Hernandez Camero, J. O'kane   +7 more
wiley   +1 more source

Looking for the FIP Effect in EUV Spectra: Examining the Solar Case [PDF]

International Astronomical Union Colloquium, 1996
Systematic differences between elemental abundances in the corona and in the photosphere have been found in the Sun. The abundance anomalies are correlated with the first ionization potentials (FIP) of the elements. The overall pattern is that low-FIP elements are preferentially enhanced relative to high-FIP elements by about a factor of four; the ...
Bernhard Haisch, Julia L. R. Saba, Jean-Paul Meyer   +2 more
openaire   +1 more source

Ionospheric Characterization Over Iran Using Multi‐Frequency IMB HF Transmitters and Global WSPRNET Reception During the 12 November 2025 Geomagnetic Storm

Space Weather, Volume 24, Issue 6, June 2026.
Abstract The Ionospheric Monitoring Beacon network in Iran provides continuous, multi‐frequency high‐frequency (HF) transmissions using WSPRNET modulation, enabling global reception and near–real‐time monitoring of ionospheric propagation conditions.
A. Mahmoudian, Saba Hafizi Lotfabadi, Mohammad Azimi   +2 more
wiley   +1 more source