Results 41 to 50 of about 5,479 (219)

Pengaruh penginapan ke atas disiplin pelajar di Universiti Tun Hussein Onn Malaysia [PDF]

, 2008
Kajian pengaruh penginapan ke atas disiplin pelajar di Universiti Tun Hussein Onn Malaysia (UTHM) ini memfokuskan kepada tiga objektif iaitu mengenal pasti tahap kriteria penginapan dari aspek fizikal dan bukan fizikal yang memberi kesan terhadap ...
Yaacob, Mohd Asmedi
core  

Detection of Equatorial Plasma Bubbles Using the COSMIC‐2 Rate of TEC Index

Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract Equatorial plasma bubbles (EPBs) are large‐scale plasma depletion structures that can disrupt Global Navigation Satellite Systems (GNSS) and other space‐based technologies. Several instruments have been employed to study EPB dynamics, with Total Electron Content (TEC) and Rate of TEC change Index (ROTI) data standing out as valuable parameters
Ana L. Christovam, Fabricio S. Prol, Marcio T. A. H. Muella   +2 more
wiley   +1 more source

Introducing Reflected GNSS TEC Data Into ANCHOR Ionospheric Data Assimilation Model

Space Weather, Volume 24, Issue 5, May 2026.
Abstract ANCHOR is a novel data assimilation (DA) algorithm developed at the U.S. Naval Research Laboratory to improve ionospheric nowcasting by increasing accuracy and decreasing computational cost. As a parameterized DA model, ANCHOR represents the ionosphere using physical parameters such as the F2 layer peak (Nm $Nm$F2), which characterizes a ...
Brenna Royersmith, Victoriya V. Forsythe, Brian Breitsch, Meghan R. Burleigh, Kate A. Zawdie, Y. Jade Morton   +5 more
wiley   +1 more source

Multi‐Decadal Trends in the Low Latitude foF2 Driven by Secular Magnetic Variations

Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract Long‐term ionospheric trends have been widely studied, but their origin and magnitude remain subjects of debate. This study quantifies the linear trend in the F2‐region critical frequency (foF2) and its local time dependence using observations from eight low‐latitude ionosonde stations.
D. Singh, S. R. Zhang, L. P. Goncharenko, I. S. Batista, A. J. Coster   +4 more
wiley   +1 more source

Peak characteristics of F2 region over Tucumán: Predictions and measurements [PDF]

, 2008
Ionosonde measurements obtained at Tucuman are used to check the validity of the International Reference Ionosphere model to predict the maximum electron density of F2 region (NmF2) and its height (hmF2) over this station. Data corresponding to different
Ezquer, Rodolfo Gerardo, López, J., Mosert, Marta Estela, Scida, Luis Alberto   +3 more
core   +1 more source

Can the International Reference Ionosphere Model Predict Long‐Term Trends in the Ionosphere?

Geophysical Research Letters, Volume 53, Issue 8, 28 April 2026.
Abstract The International Reference Ionosphere (IRI) model can partially reproduce ionospheric long‐term trends (LTTs), although not intentionally, provided that an appropriate effective ionospheric index is used. We evaluate how model predictions driven by a solar activity proxy (R12) and by an effective ionospheric proxy (IG12) can reproduce the ...
A. Pignalberi, M. Pietrella, T. Alberti, M. Pezzopane   +3 more
wiley   +1 more source

Comparison of Seasonal foEs and fbEs Occurrence Rates Derived from Global Digisonde Measurements

Atmosphere, 2021
A global climatology of sporadic-E occurrence rates (ORs) based on ionosonde measurements is presented for the peak blanketing frequency, fbEs, and the ordinary mode peak frequency of the layer, foEs.
Dawn K. Merriman, Omar A. Nava, Eugene V. Dao, Daniel J. Emmons   +3 more
doaj   +1 more source

Relatively Intense Daytime GNSS Amplitude Scintillations at Middle Latitude Linked With Multi‐Layered Strong Es Structures

Geophysical Research Letters, Volume 53, Issue 8, 28 April 2026.
Abstract Intense Global Navigation Satellite System (GNSS) amplitude scintillations usually occur in nighttime at low latitudes due to ionospheric plasma bubble irregularities. During daytime at middle latitudes, previous studies found that the sporadic E (Es) layer could lead to GNSS amplitude scintillations, which however, is relatively weak, for ...
Wenjie Sun, Yuichi Otsuka, Guozhu Li, Zhe Yang, Yuanfa Ji, Wenbin Liang, Renjin Zhang, Xiukuan Zhao, Lianhuan Hu, Biqiang Zhao, Jianfei Liu, Guofeng Dai, Yi Li, Haiyong Xie, Baiqi Ning   +14 more
wiley   +1 more source

Multilayered Sporadic‐E Response to the Annular Solar Eclipse on June 21, 2020

Space Weather, 2021
A moon shadow of annular solar eclipse passed through East Asia in the afternoon on June 21, 2020, which was a good opportunity to study the rapid ionospheric response to the solar radiation variations. In the study, the high‐frequency echoes recorded by
Jin Wang, Xiaomin Zuo, Yang‐Yi Sun, Tao Yu, Yungang Wang, Lihui Qiu, Tian Mao, XiangXiang Yan, Na Yang, Yifan qi, Jiuhou Lei, Lingfeng Sun, Biqiang Zhao   +12 more
doaj   +1 more source

Topside Ionosphere and Plasmasphere Modelling Using GNSS Radio Occultation and POD Data

Remote Sensing, 2021
A 3D-model approach has been developed to describe the electron density of the topside ionosphere and plasmasphere based on Global Navigation Satellite System (GNSS) measurements onboard low Earth orbit satellites.
Fabricio S. Prol, M. Mainul Hoque
doaj   +1 more source