Results 121 to 130 of about 12,196 (218)

Seasonal Variations of the Martian Middle‐Atmosphere CO2/Ar Ratio Inferred From MAVEN/NGIMS Observations

Geophysical Research Letters, Volume 53, Issue 20, 28 October 2026.
Abstract The carbon dioxide (CO2)/argon (Ar) ratio is a useful tracer of atmospheric circulation on Mars, but it remains observationally poorly constrained in the middle atmosphere, where large‐scale circulation occurs. In this study, we infer the CO2/Ar ratio at the homopause, which marks the upper boundary of the well‐mixed Martian middle atmosphere,
JunFeng Qin, Shannon Curry, Michael S. Chaffin, Yuni Lee, François Forget   +4 more
wiley   +1 more source

Gamma‐Ray Glows Commonly Followed by Lightning: A Statistical Study of the Spatio‐Temporal Relationship

Geophysical Research Letters, Volume 53, Issue 20, 28 October 2026.
Abstract Gamma‐ray glows are prolonged enhancements of gamma rays from thunderclouds, which are often linked to large‐scale electric fields rather than individual lightning. The link between glows and lightning remains poorly understood. Here, we analyzed 300 glows observed during the ALOFT aircraft campaign and optical lightning detected by GLM.
Chu‐Nan Zhang, Yunjiao Pu, Steven Cummer, Martino Marisaldi, Nikolai Østgaard, Andrey Mezentsev, Ingrid Bjørge‐Engeland, Øystein Håvard Færder, David Alexandre Stephan Sarria, Nikolai G. Lehtinen, Anders Nødland Fuglestad   +10 more
wiley   +1 more source

Laboratory Astrophysics [PDF]

, 2018
openaire   +1 more source

A Study of Kelvin‐Helmholtz Instability at Unmagnetized Planets by Finite Larmor Radius MHD

Geophysical Research Letters, Volume 53, Issue 20, 28 October 2026.
Abstract Kelvin–Helmholtz instability (KHI) at unmagnetized planetary ionopauses plays a key role in driving solar wind–ionosphere coupling and planetary ion escape. We investigate KHI using a two‐dimensional finite Larmor radius (FLR) MHD model.
Caiyi Fei, Maodong Yan, Jiuhou Lei
wiley   +1 more source

Seasonal and Diurnal Variability of Thermospheric Metastable Helium Observed by Multi‐Platform Observations and Numerical Modeling

Geophysical Research Letters, Volume 53, Issue 20, 28 October 2026.
Abstract Metastable helium (He∗ ${\text{He}}^{\ast }$) in the thermosphere emits at 1,083 nm and provides a powerful diagnostic of thermospheric composition, solar radiation, and transport. Its detection remains challenging because of its extremely low density and high‐altitude.
Zhenwei Liu, Chuan Huang, Jinru Cheng, Tangsheng Cheng, Hang Zhou, Chaomei Wu, Chen Liang, Tingdi Chen, Weilong Luo, Chong Wang, Zhaofeng Wang, Ruocan Zhao, Xianghui Xue   +12 more
wiley   +1 more source

Quasi‐Homologous Solar Flares and Impacts on Thermospheric Density and Satellite Orbital Drag

Geophysical Research Letters, Volume 53, Issue 20, 28 October 2026.
Abstract Quasi‐Homologous Flaring (QHF) activity from active regions on the Sun releases intense electromagnetic radiation in recurrent bursts over extended periods. In this letter, we present the effects of recurrent impulsive extreme ultraviolet (EUV) heating on thermospheric neutral density and the resulting atmospheric drag on satellites based on ...
S. Tulasi Ram, Princy K. Dubey, S. Mondal, Denny M. Oliveira, Jayashree Bulusu, Chinmaya Nayak, D. Rout, Anil Raghav, A. P. Dimri   +8 more
wiley   +1 more source

A laboratory astrophysics problem

, 2020
Emission lines of singly charged ions populate many astrophysical spectra. However, the interpretation of the line intensities (usually line ratios) often depends on the transition rates of the decays of very long-lived low-lying levels. For example, the line ratio of two electric-dipole forbidden transitions in the \(3s^{2} 3p^{3}\) ground ...
openaire   +1 more source

Measuring and Mapping Urban NO2 Pollution Heterogeneity Using a Custom Pandora Spectrometer Experiment and Observations From TEMPO

Journal of Geophysical Research: Atmospheres, Volume 131, Issue 20, 28 October 2026.
Abstract Nitrogen dioxide (NO2) is a primary pollutant present at high concentrations in urban areas. Ground based measurements remain sparse and satellite observations rely on retrievals, so understanding intraurban, diurnal‐scale changes in NO2 is challenging.
R. H. Mooers, J. A. Geddes, C. Naughton, A. Pandey, B. K. Place, G. González Abad, N. Lombel   +6 more
wiley   +1 more source

The Evolution of Parallel Electric Field Across the Earth's Magnetosheath

Geophysical Research Letters, Volume 53, Issue 19, 16 October 2026.
Abstract In Earth's collisionless magnetosheath, turbulence evolution and energy transformation across the system, especially at kinetic scales, remain poorly quantified without full‐coverage of high‐resolution observations. Using multi‐traversal observations from the 2023 and 2024 Magnetospheric Multiscale (MMS) Unbiased Magnetosheath Campaign, we ...
Y. Qi, R. E. Ergun, T. Vo, A. Chasapis, S. J. Schwartz, V. Wilder   +5 more
wiley   +1 more source

Star formation powers optical line emission from the CGM. [PDF]

Sci Adv
Zhang H, Xie L, Qu Z, Zaritsky D, Ho LC, Bao M, Fontanot F, Hirschmann M, Liu C, De Lucia G, Wang E, Zheng H.   +11 more
europepmc   +1 more source