GUVI Biblio


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Found 2061 entries in the Bibliography.

Showing entries from 201 through 250


Quantifying the Impact of Dynamic Storm-Time Exospheric Density on Plasmaspheric Refilling

Waldrop, Lara; Cucho-Padin, Gonzalo; Maruyama, Naomi;

Published by: Earth and Space Science Open Archive ESSOAr      Published on:

YEAR: 2021     DOI:

Transpolar arcs: Seasonal dependence identified by an automated detection algorithm

Bower, Gemma; Milan, Stephen; Paxton, Larry;

Published by: Earth and Space Science Open Archive ESSOAr      Published on:

YEAR: 2021     DOI:

Ionospheric and thermospheric contributions in TIMED/GUVI O 135.6 nm radiances

Zhang, Yongliang; Paxton, Larry; Schaefer, Robert;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI:

Large Electron Densities in the Early Morning Equatorial Ionosphere Observed with UV Instruments from Space

Schaefer, Robert; Paxton, Larry; Zhang, Yongliang; Kil, Hyosub; Romeo, Giuseppe; Wolven, Brian; Yonker, Justin;

Published by:       Published on:

YEAR: 2021     DOI:

A precipitation parameterization for the Empirical Canadian High Arctic Ionospheric Model (E-CHAIM) and other empirical models

Themens, David; Jayachandran, Thayyil; McCaffrey, Anthony; Reid, Benjamin; Watson, Chris;

Published by: 43rd COSPAR Scientific Assembly. Held 28 January-4 February      Published on:

YEAR: 2021     DOI:

Dual-lobe reconnection and cusp-aligned auroral arcs

Milan, Stephen; Bower, Gemma; Carter, Jennifer; Paxton, Larry; Anderson, Brian; Hairston, Marc;

Published by:       Published on:

YEAR: 2021     DOI:

Development and validation of precipitation enhanced densities for the Empirical Canadian High Arctic Ionospheric Model

Watson, C; Themens, DR; Jayachandran, PT;

Published by: Space Weather      Published on:

YEAR: 2021     DOI:

The Universal Time Variations of the Intensity of Afternoon Aurora in Equinoctial Seasons

The afternoon auroral emissions are investigated in the equinoxes for geomagnetically quiet conditions (Kp = 1) using auroral images from ultraviolet imager (UVI) aboard the Polar satellite. They are compared with solar illumination effects (the solar zenith angle [SZA] and the consequent ionospheric conductivity) and the dipole tilt angle, as well as the observational region 1 upward field-aligned currents (FACs) from AMPERE data. The averaged afternoon auroral emissions have pronounced universal time (UT) variations with v ...

Wang, Lingmin; Luan, Xiaoli; Lei, Jiuhou; Lynch, Kristina; Zhang, Binzheng;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028504

afternoon auroral emissions; auroral hot spots; dipole tilt angle; region 1 upward FACs; solar zenith angle; UT variations

The Delayed Ionospheric Response to the 27-day Solar Rotation Period Analyzed With GOLD and IGS TEC Data

The delayed ionospheric response is analyzed for two well-defined 27-day solar rotation periods in the year 2019 with solar radio flux index F10.7 and Global-scale Observations of the Limb and Disk (GOLD) data, like solar extreme ultraviolet (EUV) flux proxy, O/N2 column density ratio and peak electron density, as well as International Global Navigation Satellite System Service rapid high-rate total electron content (TEC) map data. Although the correlation between GOLD solar EUV flux proxy and TEC is similar to the correlati ...

Schmölter, Erik; Berdermann, Jens; Codrescu, Mihail;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028861

Ionosphere; solar proxies; time delay; total electron content

MLT Science Enabled by Atmospheric Lidars

With the pioneering development and deployment of different types of narrowband sodium fluorescence lidars in Europe (1985) and North America (1990) along with subsequent potassium and iron lidars, temperature and wind profilers have been observed to investigate atmospheric dynamics in the mesosphere and lower thermosphere (MLT) in midlatitude, polar and equatorial regions. Their achieved resolution allows investigation ranging from small-scale gravity waves to long-term global change. This chapter highlights MLT science ena ...

She, Chiao-Yao; Liu, Alan; Yuan, Tao; Yue, Jia; Li, Tao; Ban, Chao; Friedman, Jonathan;

Published by:       Published on:

YEAR: 2021     DOI: 10.1002/9781119815631.ch20

Geomagnetic storms; atmospheric stabilities; atmospheric state; climatology; clustered instrumentation; gravity wave dynamics; MLT science; resonance fluorescence lidars; sporadic metal layers; thermospheric metal layers

Impact of Storm-Enhanced Density (SED) on Ion Upflow Fluxes During Geomagnetic Storm

The impact of the dynamic evolution of the Storm-Enhanced Density (SED) on the upward ion fluxes during the March 06, 2016 geomagnetic storm is studied using comprehensive multi-scale datasets. This storm was powered by a Corotating Interaction Region (CIR), and the minimum Sym-H reached ∼−110 nT. During the ionospheric positive storm phase, the SED formed and the associated plume and polar cap patches occasionally drifted anti-sunward across the polar cap. When these high-density structures encountered positive vertica ...

Zou, Shasha; Ren, Jiaen; Wang, Zihan; Sun, Hu; Chen, Yang;

Published by: Frontiers in Astronomy and Space Sciences      Published on:

YEAR: 2021     DOI:

Evaluating Auroral Forecasts Against Satellite Observations

The aurora is a readily visible phenomenon of interest to many members of the public. However, the aurora and associated phenomena can also significantly impact communications, ground-based infrastructure, and high-altitude radiation exposure. Forecasting the location of the auroral oval is therefore a key component of space weather forecast operations. A version of the OVATION-Prime 2013 auroral precipitation model (Newell et al., 2014, was used by the UK Met Office Space Weather Operat ...

Mooney, M.; Marsh, M.; Forsyth, C.; Sharpe, M.; Hughes, T.; Bingham, S.; Jackson, D.; Rae, I.; Chisham, G.;

Published by: Space Weather      Published on:

YEAR: 2021     DOI: 10.1029/2020SW002688

AURORA; auroral forecasting; forecast verification; OVATION-Prime 2013; ROC scores; space weather

Assimilative Mapping of Electron Flux Using SSUSI Lyman-Birge-Hopfield Emissions

Far ultraviolet (FUV) imaging of the aurora from space provides great insight into the dynamic coupling of the Earth’s atmosphere, ionosphere and magnetosphere on global scales. To gain quantitative understanding of these coupling processes, the global distribution of auroral energy flux is required, but the inversion of FUV emission to derive precipitating auroral particles’ energy flux is not straightforward. Furthermore, the spatial coverage of FUV imaging from LEO altitudes is often insufficient to achieve global map ...

Li, Jason;

Published by:       Published on:

YEAR: 2021     DOI:

Assimilative mapping; Electron flux; Far ultraviolet imaging; Lyman-Birge-Hopfield emission

A Comparative Study of Ionospheric Day-To-Day Variability Over Wuhan Based on Ionosonde Measurements and Model Simulations

Ionospheric day-to-day variability is essential for understanding the space environment, while it is still challenging to properly quantify and forecast. In the present work, the day-to-day variability of F2 layer peak electron densities (NmF2) is examined from both observational and modeling perspectives. Ionosonde data over Wuhan station (30.5°N, 114.5°E; 19.3°N magnetic latitude) are compared with simulations from the specific dynamics Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension ...

Zhou, Xu; Yue, Xinan; Liu, Han-Li; Lu, Xian; Wu, Haonan; Zhao, Xiukuan; He, Jianhui;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028589

Ionosphere; day-to-day variability; ionosonde; NmF2; TIEGCM; WACCM-X

Thermospheric Composition and Solar EUV Flux From the Global-Scale Observations of the Limb and Disk (GOLD) Mission

Observations of far-ultraviolet (FUV) dayglow by the Global-scale Observations of Limb and Disk (GOLD) mission provide a new opportunity to monitor relative composition changes in the upper atmosphere as well as solar extreme ultraviolet (EUV) variability. Relative composition changes are quantified by ΣO/N2, the column density ratio of atomic oxygen to molecular nitrogen, while QEUV provides a measure of the solar EUV energy flux from 1 to 45 nm into the upper atmosphere. This spectral range provides the ionizing radiation ...

Correira, J.; Evans, J.; Lumpe, J.; Krywonos, A.; Daniell, R.; Veibell, V.; McClintock, W.; Eastes, R.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029517

GOLD; neutral composition; ON2; QEUV; radiative recombination; thermosphere

Generation of Subauroral Longitudinally Extended Emissions Following Intensifications of the Poleward Boundary of the Substorm Bulge and Streamer Production

Observations showing the development of Subauroral Longitudinally Extended Emigerssions on a global scale are presented. It is demonstrated that they occur as a separation of an east-west arc-like band of luminosity that detaches away from the equatorward edge of the auroral distribution following episodes of auroral streamer production. They persist for time intervals on the order of ∼30 min and devolve into patchy disjointed segments before they fade. Emissions are seen in both 557.7 nm OI and 391.4 nm 1NG lines, and 630 ...

Henderson, Michael;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028556

Giant Undulations; STEVE; streamers; Subauroral Bands; Subauroral Polarization Streams; substorms

Ionospheric Response Over Brazil to the August 2018 Geomagnetic Storm as Probed by CSES-01 and Swarm Satellites and by Local Ground-Based Observations

The geomagnetic storm that occurred on 25 August 25 2018, that is, during the minimum of solar cycle 24, is currently the strongest ever probed by the first China Seismo-Electromagnetic Satellite (CSES-01). By integrating the in situ measurements provided by CSES-01 (orbiting at altitude of 507 km) and by Swarm A satellite (orbiting at ca., 460 km) with ground-based observations (ionosondes, magnetometers, and Global Navigation Satellite System receivers), we investigate the ionospheric response at lower- and mid-latitudes o ...

Spogli, L.; Sabbagh, D.; Regi, M.; Cesaroni, C.; Perrone, L.; Alfonsi, L.; Di Mauro, D.; Lepidi, S.; Campuzano, S.; Marchetti, D.; De Santis, A.; Malagnini, A.; Scotto, C.; Cianchini, G.; Shen, Xu; Piscini, A.; Ippolito, A.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028368

Geomagnetic storms; Equatorial Electrojet; in situ plasma density; ionospheric elctroduamics; Ionospheric storms; low-latitude ionosphere

First Comparison of Traveling Atmospheric Disturbances Observed in the Middle Thermosphere by Global-Scale Observations of the Limb and Disk to Traveling Ionospheric Disturbances Seen in Ground-Based Total Electron Content Observations

Traveling ionospheric disturbances (TIDs) and their neutral counterparts known as traveling atmospheric disturbances (TADs) are believed to play a role in communicating inputs to other locations in the fluid. While these two phenomena are believed to be connected, they may not have a one-to-one correspondence as the geomagnetic field influences the TID but has no direct impact on the TAD. The relative amplitudes of the perturbations seen in the ionosphere and atmosphere have been observed but rarely together. This study repo ...

England, Scott; Greer, Katelynn; Zhang, Shun-Rong; Evans, Scott; Solomon, Stanley; Eastes, Richard; McClintock, William; Burns, Alan;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029248

Ionosphere; thermosphere; airglow; atmospheric waves

Low-Latitude Zonal Ion Drifts and Their Relationship With Subauroral Polarization Streams and Auroral Return Flows During Intense Magnetic Storms

We analyze horizontal plasma drifts measured by the Defense Meteorological Satellite Program satellites during two intense magnetic storms. It is found, for the first time, that westward plasma flows associated with subauroral polarization streams (SAPS) in the dusk-evening sector penetrate continuously to equatorial latitudes. The westward ion drifts between subauroral and equatorial latitudes occur nearly simultaneously. The latitudinal profile of the westward ion drifts at low latitudes (approximately within ±30° magnet ...

Huang, Chao-Song; Zhang, Yongliang; Wang, Wenbin; Lin, Dong; Wu, Qian;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA030001

Electric field; Ionosphere; ionospheric plasma drift; penetration electric field; Subauroral Polarization Streams; thermospheric wind

Equatorial Ionization Anomaly Variations During Geomagnetic Storms

The equatorial ionization anomaly (EIA) was discovered in the 1940s. Since then, the research on ionospheric storm effects at the equatorial and low latitudes has become one of the hottest topics in the ionospheric community. During the past 2 decades, large amounts of ionospheric and thermospheric data from the ground-based and satellite-borne observations and also from the novel capability of three-dimensional numerical models stimulated the ionospheric weather studies. Recent scientific progresses on the EIA response to g ...

Luan, Xiaoli;

Published by:       Published on:

YEAR: 2021     DOI: 10.1002/9781119815617.ch13

Geomagnetic storms; Equatorial ionization anomaly; equatorial ionospheric response; equatorial regions; low latitude regions; physical mechanisms

New Measurement of the Vertical Atmospheric Density Profile From Occultations of the Crab Nebula With X-Ray Astronomy Satellites Suzaku and Hitomi

We present new measurements of the vertical density profile of the Earth s atmosphere at altitudes between 70 and 200 km, based on Earth occultations of the Crab Nebula observed with the X-ray Imaging Spectrometer onboard Suzaku and the hard X-ray Imager onboard Hitomi. X-ray spectral variation due to the atmospheric absorption is used to derive tangential column densities of the absorbing species, that is, N and O including atoms and molecules, along the line of sight. The tangential column densities are then inverted to ob ...

Katsuda, Satoru; Fujiwara, Hitoshi; Ishisaki, Yoshitaka; Yoshitomo, Maeda; Mori, Koji; Motizuki, Yuko; Sato, Kosuke; Tashiro, Makoto; Terada, Yukikatsu;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028886

Crab Nebula; Hitomi; occultation; Suzaku; upper atmosphere; X-rays

A Synoptic-Scale Wavelike Structure in the Nighttime Equatorial Ionization Anomaly

Both ground- and satellite-based airglow imaging have significantly contributed to understanding the low-latitude ionosphere, especially the morphology and dynamics of the equatorial ionization anomaly (EIA). The NASA Global-scale Observations of the Limb and Disk (GOLD) mission focuses on far-ultraviolet airglow images from a geostationary orbit at 47.5°W. This region is of particular interest at low magnetic latitudes because of the high magnetic declination (i.e., about -20°) and proximity of the South Atlantic magnetic ...

Rodríguez-Zuluaga, J.; Stolle, C.; Yamazaki, Y.; Xiong, C.; England, S.;

Published by: Earth and Space Science      Published on:

YEAR: 2021     DOI: 10.1029/2020EA001529

equatorial plasma bubbles; Equatorial ionization anomaly; Equatorial ionosphere; forcing from below; wave structure

Plasma depletions lasting into daytime during the recovery phase of a geomagnetic storm in May 2017: Analysis and simulation of GPS total electron content observations

This paper reports that plasma density depletions appearing at middle latitudes near sunrise survived until afternoon on 29 May 2017 during the recovery phase of a geomagnetic storm. By analyzing GPS data collected in Japan, we investigate temporal variations in the horizontal two-dimensional distribution of total electron content (TEC) during the geomagnetic storm. The SYM-H index reached −142 nT around 08 UT on 28 May 2017. TEC depletions extending up to approximately 38°N along the meridional direction appeared over Ja ...

Otsuka, Yuichi; Shinbori, Atsuki; Sori, Takuya; Tsugawa, Takuya; Nishioka, Michi; Huba, Joseph;

Published by: Earth and Planetary Physics      Published on:

YEAR: 2021     DOI: 10.26464/epp2021046

Ionosphere; GPS; ionospheric irregularity; plasma bubble; SAMI2

Global Effects of a Polar Solar Eclipse on the Coupled Magnetosphere-Ionosphere System

It is well-known that solar eclipses can significantly impact the ionosphere and thermosphere, but how an eclipse influences the magnetosphere-ionosphere system is still unknown. Using a coupled magnetosphere-ionosphere-thermosphere model, we examined the impact on geospace of the northern polar-region eclipse that occurred on June 10, 2021. The simulations reveal that the eclipse-induced reduction in polar ionospheric conductivity causes large changes in field-aligned current, cross-polar cap potential and auroral activity. ...

Chen, Xuetao; Dang, Tong; Zhang, Binzheng; Lotko, William; Pham, Kevin; Wang, Wenbin; Lin, Dong; Sorathia, Kareem; Merkin, Viacheslav; Luan, Xiaoli; Dou, Xiankang; Luo, Bingxian; Lei, Jiuhou;

Published by: Geophysical Research Letters      Published on:

YEAR: 2021     DOI: 10.1029/2021GL096471

auroral activity; magnetosphere-ionosphere coupling; polar solar eclipse

A Globally Averaged Thermospheric Density Data Set Derived From Two-Line Orbital Element Sets and Special Perturbations State Vectors

We describe a long-term data set of global average thermospheric mass density derived from orbit data on ∼7,700 objects in low Earth orbit, via the effect of atmospheric drag. The data cover the years 1967–2019 and altitudes 250–575 km, and the temporal resolution is 3–4 days for most years. The data set is an extension and revision of a previous version. The most important change is the use of more precise orbit data: special perturbation state vectors are now used starting in 2001, instead of mean Keplerian orbital ...

Emmert, J.; Dhadly, M.; Segerman, A.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029455

orbital elements; spacecraft drag; thermosphere density

Auroral Energy Flux and Joule Heating Derived From Global Maps of Field-Aligned Currents

We calculate auroral energy flux and Joule heating in the high-latitude ionosphere for 27 geomagnetically active days using two-dimensional maps of field-aligned currents determined by the Active Magnetosphere and Planetary Response Experiment. The energy input to the ionosphere due to Joule heating increases more rapidly with geomagnetic activity than that due to precipitating particles. The energy flux varies more smoothly with time than Joule heating, which is impulsive in nature on time scales from minutes to tens of min ...

Robinson, R.; Zanetti, L.;

Published by: Geophysical Research Letters      Published on:

YEAR: 2021     DOI: 10.1029/2020GL091527

Geomagnetic storms; Auroral energy flux; auroral energy input; auroral substorms; Joule heating; ring current

Statistical Analysis of Throat Aurora Using Long Term DMSP/SSUSI Observation

Throat aurora is believed to be associated with magnetopause indentations and has direct implications on magnetopause reconnection. In this study, for the first time, we use Defense Meteorological Satellite Program/Special Sensor Ultraviolet Spectrographic Imager observations over ∼14 years to characterize the throat aurora occurrence, latitudinal extent, seasonal, and its solar cycle dependence. We identified 386 throat aurora cases during the different passes of the satellite over the northern hemisphere. The latitudinal ...

Selvakumaran, R.; Han, De-Sheng; Gokani, Sneha; Zhang, Y.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029164

auroral oval; magnetopause indentations; throat aurora

Neutral Hydrogen in the Terrestrial Thermosphere and Exosphere

The exosphere is the interface between the Earth s neutral atmosphere and interplanetary space. Our understanding of this important interface, through observations of its mean state and its response to external forcing, will provide important constraints as we seek to develop a complete picture of our complicated space-atmosphere system. This chapter will highlight the contributions of ground-based geocoronal hydrogen observations to our understanding of this system. Observations are made throughout the night; the base of th ...

Mierkiewicz, Edwin;

Published by:       Published on:

YEAR: 2021     DOI: 10.1002/9781119815631.ch8

Fabry-Perot spectrometer; geocoronal Balmer; ground-based geocoronal hydrogen observations; hydrogen density profile; hydrostatic equilibrium; neutral hydrogen; terrestrial exosphere; terrestrial thermosphere

Ionosphere and Thermosphere Coupling at Mid- and Subauroral Latitudes

This chapter addresses the ionosphere–thermosphere (I/T) coupling phenomena. We define I/T coupling as the dynamical interaction between plasma and neutral particles in the upper atmosphere. This interaction involves the ionosphere response to changes in the thermospheric wind, composition, and temperature, and how the thermosphere dynamics and thermal state are affected by plasma electrodynamics, which may well be under the influence of magnetosphere–ionosphere coupling. It has been the main research focus for decades a ...

Zhang, Shun-Rong;

Published by:       Published on:

YEAR: 2021     DOI: 10.1002/9781119815617.ch15

ionosphere–thermosphere coupling; ionospheric dynamics; ionospheric responses; subauroral latitudes; thermospheric neutral winds; thermospheric variations

Toward a Next Generation Particle Precipitation Model: Mesoscale Prediction Through Machine Learning (a Case Study and Framework for Progress)

We advance the modeling capability of electron particle precipitation from the magnetosphere to the ionosphere through a new database and use of machine learning (ML) tools to gain utility from those data. We have compiled, curated, analyzed, and made available a new and more capable database of particle precipitation data that includes 51 satellite years of Defense Meteorological Satellite Program (DMSP) observations temporally aligned with solar wind and geomagnetic activity data. The new total electron energy flux particl ...

McGranaghan, Ryan; Ziegler, Jack; Bloch, Téo; Hatch, Spencer; Camporeale, Enrico; Lynch, Kristina; Owens, Mathew; Gjerloev, Jesper; Zhang, Binzheng; Skone, Susan;

Published by: Space Weather      Published on:

YEAR: 2021     DOI: 10.1029/2020SW002684

space weather; magnetosphere-ionosphere coupling; data science; evaluation; machine learning; particle precipitation

Implication of Tidal Forcing Effects on the Zonal Variation of Solstice Equatorial Plasma Bubbles

Equatorial plasma bubbles (EPBs) are plasma depletions that can occur in the nighttime ionospheric F region, causing scintillation in satellite navigation and communications signals. Past research has shown that EPB occurrence rates are higher during the equinoxes in most longitude zones. An exception is over the central Pacific and African sectors, where EPB activity has been found to maximize during solstice. Tsunoda et al. (2015) hypothesized that the solstice maxima in these two sectors could be driven by a zonal wavenum ...

Chang, Loren; Salinas, Cornelius; Chiu, Yi-Chung; , Jones; Rajesh, P.; Chao, Chi-Kuang; Liu, Jann-Yenq; Lin, Charles; Hsiao, Tung-Yuan;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028295

Ionosphere; Atmospheric tides; equatorial plasma bubble; scintillation; vertical coupling; wind dynamo

Determination of Auroral Electrodynamic Parameters From AMPERE Field-Aligned Current Measurements

We calculate high latitude electrodynamic parameters using global maps of field-aligned currents from the Active Magnetosphere and Planetary Response Experiment (AMPERE). The model is based on previous studies that relate field-aligned currents to auroral Pedersen and Hall conductances measured by incoherent scatter radar. The field-aligned currents and conductances are used to solve for the electric potential at high latitudes from which electric fields are computed. The electric fields are then used with the conductances t ...

Robinson, R.; Zanetti, Larry; Anderson, Brian; Vines, Sarah; Gjerloev, Jesper;

Published by: Space Weather      Published on:

YEAR: 2021     DOI: 10.1029/2020SW002677

space weather; auroral currents; auroral electrodynamics; conductivities; electric fields; field-aligned currents

Explicit IMF By-Dependence in Geomagnetic Activity: Quantifying Ionospheric Electrodynamics

Geomagnetic activity is mainly driven by the southward (Bz) component of the interplanetary magnetic field (IMF), which dominates all solar wind coupling functions. Coupling functions also depend on the absolute value of the dawn-dusk (By) component of the IMF, but not on its sign. However, recent studies have shown that for a fixed level of solar wind driving, auroral electrojets in the Northern Hemisphere (NH) are stronger for By \textgreater 0 than for By \textless 0 during NH winter. In NH summer, the dependence on the B ...

Holappa, L.; Robinson, R.; Pulkkinen, A.; Asikainen, T.; Mursula, K.;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029202

space weather; magnetosphere-ionosphere coupling; field-aligned currents; geomagnetic activity

Geomagnetic Pulsations Driving Geomagnetically Induced Currents

Geomagnetically induced currents (GICs) are driven by the geoelectric field induced by fluctuations of Earth s magnetic field. Drivers of intense GICs are often associated with large impulsive events such as coronal mass ejections. To a lesser extent fluctuations from regular oscillations of the geomagnetic field, or geomagnetic pulsations, have also been identified as possible drivers of GICs. In this work we show that these low-frequency pulsations are directly observed in measured GIC data from power networks. Due to the ...

Heyns, M.; Lotz, S.; Gaunt, C.;

Published by: Space Weather      Published on:

YEAR: 2021     DOI: 10.1029/2020SW002557

space weather; geomagnetic pulsations; geomagnetically induced currents

Equatorial Ionospheric Electrodynamics

The low-latitude ionosphere is one of the most dynamic regions of the Earth s upper atmosphere. The morphology of this region is controlled by radiative and coupled chemical, neutral, and plasma transport processes. Equatorial electrodynamics plays a fundamental role on the low-latitude plasma density, total electron content (TEC), and plasma structures and waves extending from the E-region to the protonosphere. Ground-based and satellite measurements over the last six decades determined the climatology of quiet- and storm-t ...

Fejer, Bela; Maute, Astrid;

Published by:       Published on:

YEAR: 2021     DOI: 10.1002/9781119815617.ch9

total electron content; equatorial ionospheric electrodynamics; low-latitude plasma density; quiet-time equatorial plasma drifts; storm-time equatorial electric fields

Interaction Between an EMSTID and an EPB in the EIA Crest Region Over China

Few observations investigated the interaction between an electrical medium-scale traveling ionospheric disturbance (EMSTID) and an equatorial plasma bubble (EPB). This paper presents another interaction between a southwestward propagating EMSTID and an eastward drifting EPB in the equatorial ionization anomaly (EIA) crest region of China. When the EMSTID and the EPB touched each other, several depletions of the EMSTID (EPB) showed the eastward (westward) velocity disturbances of the EPB (EMSTID) depletions. Besides, phase el ...

Sun, Longchang; Xu, JiYao; Zhu, Yajun; Xiong, Chao; Yuan, Wei; Wu, Kun; Hao, Yongqiang; Chen, Gang; Yan, Chunxiao; Wang, Zhihua; Zhao, Xiukuan; Luo, Xiaomin;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA029005

airglow; EIA crest region; Interaction between MSTID and EPB; Nighttime plasma density enhancement; Polarization of postmidnight EPB; VHF radar echoes and range spread F

Estimating Precipitating Energy Flux, Average Energy, and Hall Auroral Conductance From THEMIS All-Sky-Imagers With Focus on Mesoscales

Recent attention has been given to mesoscale phenomena across geospace (∼10 s km to 500 km in the ionosphere or ∼0.5 RE to several RE in the magnetosphere), as their contributions to the system global response are important yet remain uncharacterized mostly due to limitations in data resolution and coverage as well as in computational power. As data and models improve, it becomes increasingly valuable to advance understanding of the role of mesoscale phenomena contributions—specifically, in magnetosphere-ionosphere c ...

Gabrielse, Christine; Nishimura, Toshi; Chen, Margaret; Hecht, James; Kaeppler, Stephen; Gillies, Megan; Reimer, Ashton; Lyons, Larry; Deng, Yue; Donovan, Eric; Evans, Scott;

Published by: Frontiers in Physics      Published on:

YEAR: 2021     DOI:

Planetary Waves and Their Impact on the Mesosphere, Thermosphere, and Ionosphere

Large-scale planetary waves (also known as Rossby waves), such as the Quasi-two day wave, 5 day wave and Kelvin wave, play crucial roles in coupling the lower and middle atmosphere to the mesosphere, thermosphere and ionosphere. Upward propagation and global structure of planetary waves in the stratosphere and mesosphere are affected by the zonal mean winds. Baroclinic or barotropic instability of the background mesospheric winds can amplify the waves en route to the upper atmosphere. Fast traveling planetary waves with deep ...

Yue, Jia; Lieberman, Ruth; Chang, Loren;

Published by:       Published on:

YEAR: 2021     DOI: 10.1002/9781119815631.ch10

barotropic instability; E-region dynamo electric fields; F-region dynamo electric fields; Kelvin waves; mesosphere; planetary waves; plasma drift; thermosphere-ionosphere system

An Observational Investigation of Mid-Latitude Thermospheric Temperatures and High-Latitude E-Region Neutral Wind Structures

The Earth s atmosphere is a complicated environment. Different physical processes affect it depending on the altitude and latitude, among other factors. Three different aspects of the Earth s upper atmosphere are investigated here, using two different techniques. These investigations are: the mid-latitude midnight temperature maximum (MTM), the mesosphere and low-thermosphere Kelvin-Helmholtz instability (KHI), and the advective acceleration in the E-region. All of these studies occur in the Earth s thermosphere and expand o ...

de Mesquita, Rafael;

Published by:       Published on:

YEAR: 2021     DOI:

Advective acceleration; E-region neutral wind forcing; Kelvin-Helmholtz instability; Midnight temperature maximum

Semi-annual, annual and Universal Time variations in the magnetosphere and in geomagnetic activity: 4. Polar Cap motions and origins of the Universal Time effect

We use the \textlessi\textgreateram\textlessi/\textgreater, \textlessi\textgreateran, as\textlessi/\textgreater and the \textlessi\textgreateraσ\textlessi/\textgreater geomagnetic indices to the explore a previously overlooked factor in magnetospheric electrodynamics, namely the inductive effect of diurnal motions of the Earth’s magnetic poles toward and away from the Sun caused by Earth’s rotation. Because the offset of the (eccentric dipole) geomagnetic pole from the rotational axis is roughly twice as large in the so ...

Lockwood, Mike; Haines, Carl; Barnard, Luke; Owens, Mathew; Scott, Chris; Chambodut, Aude; McWilliams, Kathryn;

Published by: Journal of Space Weather and Space Climate      Published on:

YEAR: 2021     DOI: 10.1051/swsc/2020077

Middle-Low Latitude Neutral Composition and Temperature Responses to the 20 and 21 November 2003 Superstorm From GUVI Dayside Limb Measurements

TIMED/Global Ultraviolet Imager (GUVI) limb measurements of far-ultraviolet airglow emission have been used to investigate middle-low latitude thermospheric composition and neutral temperature responses to the 20 and 21 November 2003 (day of year [DOY] 324 and 325) superstorm. Altitude profiles of O, N2 number densities and temperature, as well as O/N2 column density ratio (∑O/N2), on the storm days along the GUVI limb tracks are compared with those on DOY 323 (quiet time). The storm-time composition and temperature respon ...

Yu, Tingting; Wang, Wenbin; Ren, Zhipeng; Yue, Jia; Yue, Xinan; He, Maosheng;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2020JA028427

neutral composition; altitude profile; hemispheric asymmetry in composition responses; neutral temperature; superstorm; transition heights of O responses

The Response of Middle Thermosphere (∼160 km) Composition to the November 20 and 21, 2003 Superstorm

TIMED/GUVI limb measurements and first-principles simulations from the Thermosphere Ionosphere Electrodynamics Global Circulation Model (TIEGCM) are used to investigate thermospheric atomic oxygen (O) and molecular nitrogen (N2) responses in the middle thermosphere on a constant pressure surface (∼160 km) to the November 20 and 21, 2003 superstorm. The consistency between GUVI observations and TIEGCM simulated composition changes allows us to utilize TIEGCM outputs to investigate the storm-time behaviors of O and N2 system ...

Yu, Tingting; Wang, Wenbin; Ren, Zhipeng; Cai, Xuguang; Yue, Xinan; He, Maosheng;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029449

atomic oxygen; GUVI limb observations; middle thermosphere; molecular nitrogen; storm-time perturbations; TIEGCM


Corotation of ring current auroral spots at sub-auroral latitudes

We report observations of auroral spots s at sub-auroral latitudes. The auroral spots occurred during storm-recovery phases and corotated with the Earth at a speed either higher (super-rotation) or lower (sub-rotation) than the Earth\textquoterights rotation rate. In the dawn side, the spots have a slightly higher probability of super-rotation than that of the duskside auroral spots. The super- and sub-rotation is likely due to dynamics of the plasmasphere that is controlled by both drag (sub-rotation) and solar wind driv ...

Zhang, Yongliang; Paxton, Larry;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: Jan-02-2020

YEAR: 2020     DOI: 10.1016/j.jastp.2020.105195

Auroral spots; Corotation; Sub-auroral latitude

Improving Neutral Density Predictions Using Exospheric Temperatures Calculated on a Geodesic, Polyhedral Grid

A new model of exospheric temperatures has been developed, with the objective of predicting global values with greater spatial and temporal accuracy. From these temperatures, the neutral densities in the thermosphere can be calculated, through use of the Naval Research Laboratory Mass Spectrometer and Incoherent Scatter radar Extended (NRLMSISE-00) model. The exospheric temperature model is derived from measurements of the neutral densities on several satellites. These data were sorted into triangular c ...

Weimer, D.; Mehta, P.; Tobiska, W.; Doornbos, E.; Mlynczak, M.; Drob, D.; Emmert, J.;

Published by: Space Weather      Published on: 12/2019

YEAR: 2020     DOI: 10.1029/2019SW002355

Multi-scale ionosphere responses to the May 2017 magnetic storm over the Asian sector

We investigate multi-scale ionospheric responses to the May 27, 2017, geomagnetic storm over the Asian sector by using multi-instrumental observations, including ground-based global navigation satellite systems (GNSS) network, constellation observing system for meteorology, ionosphere and climate radio occultation, the FengYun-3C (FY-3C) GNSS occultation sounder electron density profiles and in situ plasma density observations provided by both Swarm and defense meteorological satellite program missions. This geomagnetic s ...

Liu, Lei; Zou, Shasha; Yao, Yibin; Aa, Ercha;

Published by: GPS Solutions      Published on: 12/2019

YEAR: 2020     DOI: 10.1007/s10291-019-0940-1

Blob structure; Positive and negative ionosphere responses; TID; Geomagnetic storms

Effect of moderate geomagnetic storms on equatorial plasma bubbles over eastern Africa in the year 2012: Evolution and electrodynamics

Equatorial plasma bubbles (EPBs) are common features of the equatorial and low-latitude ionosphere and are known to cause radio wave scintillation which leads to the degradation of communication and navigation systems. Although these structures have been studied for decades, a full understanding of their evolution and dynamics remains important for space weather mitigation purposes. In this study, we present cases of EPBs occurrences around April and July 2012 geomagnetic storm periods over the African ...

Giday, Nigussie; Katamzi-Joseph, Zama; Stoneback, Russell;

Published by: Advances in Space Research      Published on: 04/2020

YEAR: 2020     DOI: 10.1016/j.asr.2020.01.013

C/NOFS; Equatorial electrojets; equatorial plasma bubbles

A method to derive global O/N2 ratios from SSUSI/DMSP based on Re-AURIC algorithm

Global thermospheric O/N2 column density ratios are obtained using the SSUSI/DMSP far-ultraviolet (FUV) dayglow data and the Re-AURIC simulation results. The Re-AURIC is derived from the AURIC algorithm after some old modules are updated. The calculation processes of O/N2 ratio are then established using the simulations of Re-AURIC to calibrate the ratios of the OI 135.6\ nm emission and N2 LBHS emission from SSUSI observations. The standard deviation (1σ) and correlation co ...

Ding, GuangXing; Chen, Bo; Zhang, Xiaoxin; He, Fei;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: 03/2020

YEAR: 2020     DOI: 10.1016/j.jastp.2020.105196

FUV dayglow; Magnetic storm; O/N2 ratio; Re-AURIC

Multi-wavelength coordinated observations of ionospheric irregularity structures from an anomaly crest location during unusual solar minimum of the 24th cycle

The present paper reports coordinated ionospheric irregularity measurements at optical as well as GPS wavelengths. Optical measurements were obtained from Tiny Ionospheric Photometer (TIP) sensors installed onboard the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites. GPS radio signals were obtained from a dual frequency GPS receiver operational at Calcutta (22.58\textdegreeN, 88.38\textdegreeE geographic; geomagnetic dip: 32.96\textdegree; 13.00\textdegreeN, 161.63\textdegreeE g ...

Paul, Ashik; Sur, Dibyendu; Haralambous, Haris;

Published by: Advances in Space Research      Published on: 03/2020

YEAR: 2020     DOI: 10.1016/j.asr.2019.11.035

GPS radio measurements; ionospheric irregularities; Northern crest of EIA; Optical measurements; solar minimum; TIP

Response of the low- to mid-latitude ionosphere to the geomagnetic storm of September 2017

We study the impact of the geomagnetic storm of 7\textendash9\ September\ 2017 on the low- to mid-latitude ionosphere. The prominent feature of this solar event is the sequential occurrence of two SYM-H minima with values of -146 and -115 nT on 8\ September at 01:08 and 13:56 UT, respectively. The study is based on the analysis of data from the Global Positioning System (GPS) stations and magnetic observatories located at different longitudinal sectors corresponding to the Pacific, Asia, Africa and the Amer ...

Imtiaz, Nadia; Younas, Waqar; Khan, Majid;

Published by: Annales Geophysicae      Published on: 03/2020

YEAR: 2020     DOI: 10.5194/angeo-38-359-2020

Temporal evolution of substorm-driven global Alfv\ en wave power above the auroral acceleration region

The onset of substorms is associated with bursty enhancements of Alfv\ en wave power throughout the magnetotail. While impossible to assess the total Alfv\ en wave power in the entire magnetotail, we have instead monitored waves that are funneled into the auroral acceleration region, in order to assess the temporal evolution of Alfv\ en wave power above the nightside auroral zone in relation to substorm phases. The substorms were grouped by three conditions: nonstorm periods, storm periods, and all (unc ...

Keiling, Andreas; Thaller, Scott; Dombeck, John; Wygant, John;

Published by: Journal of Geophysical Research: Space Physics      Published on: 03/2020

YEAR: 2020     DOI: 10.1029/2019JA027444

Alfven wave; Alfvenic electron; AURORA; auroral acceleration; magnetotail; Substorm

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