Results 41 to 50 of about 1,515 (120)

D‐Region Changes and Wave Activity Detected From Unusually Strong VLF Anomalies Associated With the January 2022 Tonga Volcanic Eruption

Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract We present unusually strong daytime signal amplitude anomalies of 11.1 dB on JJI and 12.6 dB on VTX very low‐frequency (VLF) transmitter signals recorded at Suva, Fiji, due to the powerful Hunga Tonga–Hunga Ha'apai (HTHH) volcanic eruption (VE) on 15 January 2022 around 04:00 UT.
Sushil Kumar, Sarwan Kumar, Mie Ichihara
wiley   +1 more source

Chemical Heating as a Feedback Mechanism in the Mesopause Region

Geophysical Research Letters, Volume 52, Issue 20, 28 October 2025.
Abstract An analytical expression is derived which shows that the release of chemical heat from exothermic chemical reactions is a negative nonlinear feedback mechanism relative to temperature in the mesopause region. This role is confirmed through model simulations. This feedback mechanism stabilizes the thermal regime of the mesopause region.
M. Grygalashvyly, W. Ward, C. C. Stephan, P. Hartogh   +3 more
wiley   +1 more source

HF radar detection of infrasonic waves generated in the ionosphere by the 28 March 2005 Sumatra earthquake [PDF]

, 2014
International audienceSurface waves generated by earthquakes create atmospheric waves detectable in the ionosphere using radio waves techniques: i.e., HF Doppler sounding, GPS and altimeter TEC measurements, as well as radar measurements.
Bourdillon, Alain, Molinié, Jean-Philippe, Occhipinti, Giovanni, Rannou, Véronique   +3 more
core   +3 more sources

Unveiling the First Impressions of the Wide‐Swath Altimetry SWOT Mission Over the Ganga River, India

Geophysical Research Letters, Volume 52, Issue 19, 16 October 2025.
Abstract The Surface Water and Ocean Topography (SWOT) mission offers novel global observations of river hydrodynamics, yet its performance across varied river morphologies remains understudied. We evaluate SWOT node and raster products over a ∼210 km stretch of the Ganga River, India, during the fast‐sampling phase, using GNSS‐based continuous ...
Pankaj R. Dhote, Ankit Agarwal, Adrien Paris, Gaurish Singhal, Praveen K. Thakur, Hind Oubanas, Daniel M. Moreira, Laetitia Gal, Vaibhav Garg, Pramod Kumar, Raghavendra P. Singh, Stephane Calmant   +11 more
wiley   +1 more source

Experimental studies of ionospheric irregularities and related plasma processes [PDF]

Utah State University (USU) continued its program of measuring and interpreting electron density and its variations in a variety of ionospheric conditions with the Experimental Studies of Ionospheric Irregularities and Related Plasma Processes program ...
Baker, Kay D.
core   +1 more source

Multiple‐Event Study of Substorm Electric Field Penetration Into Middle Latitudes Based on Simultaneous Observation of 630‐nm Airglow Enhancements at Three Stations

Journal of Geophysical Research: Space Physics, Volume 130, Issue 10, October 2025.
Abstract It is known that convection electric fields develop in the polar region associated with substorm onset, and a westward electric field penetrates to lower latitudes on the night side. Two‐dimensional observations of 630‐nm airglow enhancements associated with the westward electric field can be conducted using all‐sky cameras at middle latitudes.
S. Morita, K. Shiokawa, Y. Otsuka, N. Nshitani, A. Shinbori, A. Fujimoto, A. Yoshikawa, M. Nishioka, S. Perwitasari, M. Yamamoto, T. Sori   +10 more
wiley   +1 more source

Thermospheric Density Disturbances During the 2015 St. Patrick's Day Geomagnetic Storm: Model–Observation Comparisons and Analysis of Intense Polar Density Spikes

Space Weather, Volume 23, Issue 10, October 2025.
Abstract Drag affecting satellites in low Earth orbit varies significantly during geomagnetic storms due to changes in thermospheric density. While neutral density can be inferred from satellite measurements, such data sets are limited and restrict neutral density/orbit prediction capabilities.
E. J. Blanchfield, B. A. Carter, J. L. Currie, J. M. Weygand, G. N. Iles   +4 more
wiley   +1 more source

Nocturnal Temperature and Wind Structures of the Mesosphere and Lower Thermosphere Region Over Yuzhong (36°N, 104.2°E) Based on Sodium Lidar Observation

Space Weather, Volume 23, Issue 10, October 2025.
Abstract We present an analysis of thermal and dynamical structures in the mesopause and lower thermosphere (MLT) region (82–106 km) using ∼1,870 hr of sodium (Na) lidar observations at Yuzhong (36.0°N, 104.2°E) from March 2023 to May 2025. Mesopause altitudes exhibit strong seasonal dependence, ranging from 88 km in summer to 102 km in winter, with ...
Linmei Liu, Yuan Xia, Yong Yang, Xuewu Cheng, Xin Lin, Kaijie Ji, Wei Wang, Jiaming Liang, Jinzhou Zheng, Guotao Yang, Faquan Li   +10 more
wiley   +1 more source

Equatorward Wind Driven Significant Upwelling of Ca+ Layer Over Middle Latitude During the November 2023 Strong Geomagnetic Storm

Geophysical Research Letters, Volume 52, Issue 18, 28 September 2025.
Abstract Metallic ions deposited in the Earth's atmosphere by meteoric ablation primarily occur below 105 km altitude, and sometimes could ascend to the F region altitude ∼200 km under geomagnetic quiet conditions. With the Mohe (122.3°E, 53.5°N, magnetic latitude 54.8°) lidar, we present the first observation of Ca+ layer upwelling from E to F region ...
Jing Jiao, Wenjie Sun, Lifang Du, Guotao Yang, Guozhu Li, Biqiang Zhao, Fang Wu, Wenbo Li, Haoran Zheng, Yuchang Xun, Xiaofei Wu, Chunxiao Yan, Yajun Zhu   +12 more
wiley   +1 more source

Combined Release and Radiation Effects Satellite (CRRES) Experiment: Educational planning and coordination [PDF]

The efforts conducted to provide educational planning and development support for the Combined Release and Radiation Satellite (CRRES) Experiment are summarized.
Alzmann, Melanie, Vaughan, William W.
core   +1 more source