Radars detect plasma trails created by the billions of small meteoroids that enter the Earth's atmosphere daily, returning data used to infer characteristics of the meteoroid population and upper atmosphere. Researchers use models to investigate the dynamic evolution of the trails, enabling them to better interpret radar results. This study presents a fully kinetic, three-dimensional code to explore

The Cluster mission was the first constellation using four identical spacecraft to study Sun-Earth connection plasma processes. Using four spacecraft in a tetrahedron shape, it could measure, for the first time, 3D quantities such as electrical currents, plasma gradients or divergence of the electron pressure tensor and 3D structures such as boundaries, surface waves or vortices. Launched in pairs

Accurate representation of ensemble members of coupled Ionosphere-Thermosphere (I-T) is crucial to the ionosphere forecast in the ensemble Kalman filter (EnKF) data assimilation system. In this paper, besides the model drivers used in previous studies, including the solar 10.7 cm radio flux (F10.7), auroral hemispheric power (HP) and cross-tail potential drop (CP), the eddy diffusion coefficient (ED)

A moderate geomagnetic storm (Sym/H −100 nT) during June 28 and 29, 2013 was studied using Comprehensive Inner Magnetosphere-Ionosphere (CIMI) simulations and results were compared with Two wide-angle Imaging Neutral-atom Spectrometers (TWINS) observations of the spatial and temporal evolution of ring current (RC) ions including ion pressure, anisotropy, intensity, and median energy. At the onset of

Shock waves are common in the heliosphere and beyond. The collisionless nature of most astrophysical plasmas allows for the energy processed by shocks to be partitioned amongst particle sub-populations and electromagnetic fields via physical mechanisms that are not well understood. The electrostatic potential across such shocks is frame dependent. In a frame where the incident bulk velocity is parallel

South Pole Station, Antarctica (SPA, magnetic latitude = −74.5°, magnetic local time (MLT) = UT–3.5 h), is a unique observatory which can capture daytime auroral forms throughout austral winter season. We have studied the properties and origin of ultralow-frequency (ULF) range modulation of daytime diffuse aurora, using data acquired on June 23, 2017 by multi-instrument measurements at SPA and in situ

The vertical propagation of coseismic ionospheric disturbances (CIDs) associated with the foreshock of the Tohoku earthquake was examined using an HF Doppler sounding system. The sounding system used in this study received radio waves at four different frequencies (5.006, 6.055, 8.006, and 9.595 MHz), indicating that ionospheric disturbances can be observed at up to four altitudes. CIDs were observed

We used nearly 4 years of data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter to map the distribution and motion of energetic O+ ions (2.3-30 keV) in the Martian environment. Our analysis reveals two typical features: a strong plume of energetic O+ ions in the +E hemisphere at dayside, driven by the convective electric field, and a less strong tailward gathering flow of energetic O+

A structure of polarization of magnetic field variation in the frequency range from 0.01 to 0.3 Hz was found by Kaguya in the lunar wake. In a dawnward-directed magnetic field, the polarization was left-handed in the southern hemisphere and right-handed in the northern hemisphere of the lunar wake. The sense of rotation was consistent with vortices behind an obstacle in a fast stream, although no such

We used reanalyzed Jicamarca radar measurements to study the response of equatorial ionospheric electrodynamics and spread F during the main phase of the large September 2017 geomagnetic storm. Our observations near dusk on 7 September show very large upward drifts followed by a large short-lived downward drift perturbation that completely suppressed the lower F region plasma irregularities and severely

TIMED/GUVI limb measurements of FUV airglow emission have been used to investigate middle-low latitude thermospheric composition and neutral temperature responses to the 20-21 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

A theoretical interpretation is given for MHD oscillations observed by the GOES and Cluster satellites on November 7, 2004 near the plasmapause (Zong et al., 2009; Zong et al., 2012), before and after an interplanetary shock passes through the magnetosphere (about 18:27 UT). It is shown that, after the shock front passage, the MHD oscillation spectra recorded by Cluster (C1) and GOES 12, located respectively

The distinctive features of the ion gyro-harmonic discrete structures in the narrowband stimulated electromagnetic emission (NSEE) spectra (within ±1 kHz of the heater frequency), excited by an extraordinary (X-mode) polarized HF pump wave in the F-region of the high latitude ionosphere, are reported. Results were obtained from three sets of experiments at the EISCAT (European incoherent Scatter) HF

Ionospheric plasma density data from the planar langmuir probe onboard the CHAllenging Minisatellite Payload (CHAMP) are used to investigate the latitudinal profile of the ionospheric plasma density. Along with the well-known profiles with features of the equatorial ionization anomaly and equatorial plasma bubbles, a third type is observed as smooth profiles with large-scale deep equatorial trough

The coupling response between solar wind structures and the magnetosphere is highly complex, leading to different effects in the outer radiation belt electron fluxes. Most Coronal Mass Ejections cause strong geomagnetic storms with short recovery phases, often 1-2 days. By contrast, High-Speed Solar Wind Streams lead to moderate and weak storms often with much longer recovery phases, from several to

Based on the Swarm 16 Hz Advanced Plasma Density dataset, and using the Swarm A satellite, we apply automatic detection of spectral breaks in 7 million sampled plasma density power spectra in the high-latitude F-region ionosphere. This way, we survey the presence of plasma irregularity dissipation due to an enhanced E-region conductance, caused both by solar photoionization and particle precipitation

TIMED/GUVI observed thermospheric column ∑O/N2 depletion in both hemispheres between March 1 and 21, 2017 which was caused by large periodic variations in interplanetary magnetic field (IMF) and a high solar wind speed, likely in a solar wind. The dominant periods seen in the solar wind and magnetosphere coupling function (CF) were around 1.9, 3.0, 4.7, 7.6, 14.0 and 22.0 hours on March 1 and 2. The

Localized dynamic pressure pulses in the magnetosheath, or jets, have been a popular topic for discussion in recent decades. Studies show that they can propagate through the magnetosheath and impact the magnetopause, possibly showing up as geoeffective elements at ground level. However, questions still remain on how geoeffective they can be. Previous studies have been limited to case studies during

We explore the variation in plasma conditions through the middle magnetosphere of Jupiter with latitude and radial distance using Juno-JADE measurements of plasma density (electrons, protons, sulfur, and oxygen ions) surveyed on Orbits 5–26 between March 2017 and April 2020. On most orbits, the densities exhibit regular behavior, mapping out a disk between 10 and 50 RJ (Jovian radii). In the disk,

We present the distinct responses of the nighttime ionosphere due to an intense and long lasting geomagnetic storm of December 19–21, 2015 using a chain of ionosondes from magnetic equator to anomaly crest region over India. The observations exhibited unique features throughout the night including dawn and dusk sectors. The results showed twin episodes of pre-reversal enhancement (PRE) in dusk sector

On the dayside of August 25–26, 2018 (main phase, MP of the storm), we unveiled the storm time effects on the latitudinal distribution of ionospheric total electron content (TEC). We used 17 and 19 Global Positioning System receivers in American and Asian-Australian sectors, respectively. Also, we employed a pair of magnetometers in each sector to unveil storm time effects on vertical E × B upward

The characteristics of turbulent plasma in the winter cusp ionosphere is studied based on in-situ data from the Investigation of Cusp Irregularities (ICI) sounding rockets. The electron density fluctuations from ICI-2 and ICI-3 missions have been analyzed for the whole flight, using advanced time-series analysis techniques. The analysis of the autocorrelation scale is indicative of the turbulence integral

The present study examines the low-energy ion flux variations observed by the Arase satellite in the inner magnetosphere. From the magnetic field and ion flux data obtained by the fluxgate magnetometer and the low-energy particle experiments–ion mass analyzer onboard Arase, we find 55 events of the low-energy O+ flux enhancement accompanied with magnetic field dipolarization in the periods of April

Following substorm auroral onset, the active aurora region usually expands poleward toward the poleward auroral boundary. Such poleward expansion is often associated with a bulge region that expands westward and forms the westward travelling surge. In this study, we show all-sky imager and Poker Flat Advanced Modular Incoherent Scatter Radar observations of two surge events to investigate the relationship

In this paper, the ionospheric quiet-time disturbances otherwise known as Pre-Magnetic Storm Signatures (PMS) have been studied using the F2-layer peak electron density (NmF2) data obtained from 12 Digisonde/ionosonde stations distributed across equatorial, low and mid-latitudes. The datasets used spans the years 2010-2012. Results from this study reveals strong PMS in NmF2 with percentage deviations

Auroral emissions have been extensively observed at the Earth, Jupiter, and Saturn. These planets all have appreciable atmospheres and strong magnetic fields, and their auroras predominantly originate from a region encircling each magnetic pole. However, Jupiter’s auroras poleward of these “main” emissions are brighter and more dynamic, and the drivers responsible for much of these mysterious polar

To understand the features of the quasistatic field-aligned currents (FACs) consisting of multiple mesoscale (∼10–100 km) upward and downward FAC regions in the duskside auroral oval, we examined the magnetic field data obtained through the constellation measurements of Swarm satellites for a duration of more than three years. We introduced a method of automated event identification and took the events

Fast magnetosonic (MS) waves have been found to propagate mainly in the radial direction inside the plasmasphere. One main topic about the radial propagation of MS waves is whether they would propagate down to the ground or be reflected at some regions. Since WKB assumption might become invalid near the reflection point (if the reflection happens), an analytic approach has been utilized to investigate

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

We present Jovian electron densities measured by the Juno Waves instrument at high-latitudes (with magnetic latitudes of on magnetic field lines threading the Io torus and plasma sheet (with M-shells of ) using the first 29 orbits of the Juno mission. We infer electron densities from characteristic frequency cutoffs and resonances in plasma wave spectra. Often more than one of the characteristic frequencies

Kink-like flapping motions of current sheets are commonly observed in the magnetotail. Such oscillations have periods of a few minutes down to a few seconds and they propagate toward the flanks of the plasma sheet. Here, we report a short-period ( s) flapping event of a thin current sheet observed by the Magnetospheric Multiscale spacecraft in the dusk-side plasma sheet following a fast Earthward plasma

Dispersionless injections, involving sudden, simultaneous flux enhancements of energetic particles over some broad range of energy, are a characteristic signature of the particles that are experiencing a significant acceleration and/or rapid inward transport at the leading edge of injections. We have statistically analyzed data from Van Allen Probes (also known as Radiation Belt Storm Probes [RBSP])

Radiation belt electrons undergo frequent acceleration, transport, and loss processes under various physical mechanisms. One of the most prevalent mechanisms is radial diffusion, caused by the resonant interactions between energetic electrons and ULF waves in the Pc4-5 band. An indication of this resonant interaction is believed to be the appearance of periodic flux oscillations. In this study, we

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 EIA crest region of China. When the EMSTID and the EPB touched each other, several depletions of the EMSTID (EPB) showed

We consider the physical origin of reconnection-related events in Saturn's equatorial current sheet revealed by Cassini, specifically the dipolarization events discussed by Yao et al. (2018, https://doi.org/10.1029/2018JA025837) that recur close to the ∼10.7 h planetary period oscillation (PPO) period. We argue that Yao et al.'s preferred recurrence explanation in terms of complete rotations of dipolarized

Magnetic clouds (MCs) are an important kind of interplanetary coronal mass ejections and generally treated as giant flux ropes. Previous researches indicates that the rope structure of MCs may be destructed as they move away from the solar surface. In this paper, we made a statistic study of the azimuthal flux of flux ropes embedded within MCs near 5 AU. The average azimuthal flux of the rope was estimated

The threat that solar storms pose to our ever-modernizing society has gathered significant interest in the recent past. This is partly due to the discoveries of large peaks in the content of cosmogenic radionuclides such as radiocarbon (14C) in tree rings and beryllium-10 (10Be) and chlorine-36 (36Cl) in ice cores that were linked to extreme solar storms dated to the past millennia. To better assess

The afternoon auroral emissions are investigated in the equinoxes for geomagnetically quiet conditions () using auroral images from ultraviolet imager (UVI) aboard the Polar satellite. They are compared with solar illumination effects (the solar zenith angle and the consequent ionospheric conductivity) and the dipole tilt angle, as well as the observational region 1 upward field-aligned currents (FACs)

The ionosphere of Titan hosts a complex ion chemistry leading to the formation of organic dust below 1200 km. Current models cannot fully explain the observed electron temperature in this dusty environment. To achieve new insight, we have re-analyzed the data taken in the ionosphere of Titan by the Cassini Langmuir probe (LP), part of the Radio and Plasma Wave Science package. A first paper (Chatain

The input from the solar wind (SW) and the accompanying Interplanetary Magnetic Field (IMF) is the defining feature of the solar wind-magnetosphere interactions. One of the most important SW drivers is the solar wind dynamic pressure, and most significantly its sharp changes known as pressure fronts. Sudden enhancements in solar wind dynamic pressure, , have been shown to lead to intensification of

The COSMIC radio occultation observations are used to investigate the wavenumber-4 (WN4) structure of the Sporadic E (Es) layer during 2007–2018. The WN4 pattern is observed in the Es occurrence rate over the middle- and low-latitudes. This pattern is stronger at the low-latitudes than at the middle-latitudes. It shows the peak intensity in latitude bands between 5° and 15° dip latitudes in both hemispheres

Observations of Earth's bow shock with high (ratio of thermal to magnetic pressure) are rare. However, such shocks are supposed to be ubiquitous in astrophysical plasmas. We present statistics of several tens crossings with for MMS, Cluster and Geotail, 30 of which have . For the latter subset, most of the crossings reveal upstream structure with the periodically emerging activations, gradually thermalizing

Magnetic reconnection is a fundamental physical process in planetary magnetospheres, in which plasma can be exchanged between the solar wind and a planetary magnetosphere, and material can be disconnected and ultimately lost from a magnetosphere. Magnetic reconnection in a planetary magnetotail can result in the release of plasmoids downtail and dipolarizations planetward of an x-line. The signatures

No abstract is available for this article.

The pursuit of realistic simulation of the physics of plasma transport, ring current formation and storm-triggered Earth magnetic and electric field is an ongoing challenge in magnetospheric physics. To this end, we have implemented a coupling of the Lyon-Fedder-Mobarry (LFM) global MHD model with the Rice convection model - equilibrium (RCM-E) of the inner-magnetosphere and plasma sheet. This one-way

The solar wind plays important roles on terrestrial magnetosphere dynamics, including the particle population and plasma waves generation. Here we report an interesting event that ULF waves are enhanced right after solar wind compression and the compressional mode ULF wave subsequently modulates both the intensity and energy flux direction of whistler-mode waves. Quasi-periodic whistler-mode wave packets

Extreme space weather events can episodically release solar energetic particles (SEPs) that precipitate into planetary atmospheres, leading to aurora and increased ionization. While the induced magnetosphere of Mars does not substantially obstruct SEP protons, the effect on SEP electrons is not known. We use a test particle model modified for relativistic electrons to model transport of 10-200 keV

We propose a new method of the automated identification of current sheets (CSs) that represents a formalization of the visual inspection approach employed in case studies. CSs are often identified by eye via the analysis of characteristic changes in the interplanetary magnetic field (IMF) and plasma parameters. Known visual and semi-automated empirical methods of CS identification are exact but do

Radial diffusion is one of the dominant physical mechanisms driving acceleration and loss of radiation belt electrons. A number of parameterizations for radial diffusion coefficients have been developed, each differing in the dataset used. Here, we investigate the performance of different parameterizations by Brautigam and Albert (2000), Brautigam et al. (2005), Ozeke et al. (2014), Ali et al. (2015);

We report plasma wave observations of equatorial magnetosonic waves at integer harmonics of the local gyrofrequency of doubly-ionized helium (He). The waves were observed by Van Allen Probe A on 08 Feb 2014 when the spacecraft was in the afternoon magnetic local time sector near inside of the plasmasphere. Analysis of the complementary in-situ energetic ion measurements (1-300 keV) reveals the presence

Current models of Titan's ionosphere have difficulties in explaining the observed electron density and/or temperature. In order to get new insights, we re-analyzed the data taken in the ionosphere of Titan by the Cassini Langmuir probe (LP), part of the Radio and Plasma Wave Science (RPWS) instrument. This is the first of two papers that present the new analysis method (current paper) and statistics

We present a global survey of energetic electron precipitation from the equatorial magnetosphere due to hiss waves in the plasmasphere and plumes. Using Van Allen Probes measurements, we calculate the pitch angle diffusion coefficients at the bounce loss cone, and evaluate the energy spectrum of precipitating electron flux. Our ∼6.5-year survey shows that, during disturbed times, hiss inside the plasmasphere

Data from a network of high-frequency (HF) beacons deployed in Peru are used to estimate the regional ionospheric electron density in a volume. Pseudorange, accumulated carrier phase, and signal power measurements for each of the 36 ray paths provided by the network at a 1 min cadence are incorporated in the estimates. Additional data from the Jicamarca incoherent scatter radar, the Jicamarca sounder

Medium-scale traveling ionospheric disturbances (MSTIDs) are a phenomenon widely and frequently observed over the ionosphere from high to low latitudes. Nighttime MSTIDs are caused generally by the polarization electric field in the ionosphere. However, propagation of this polarization electric field to the magnetosphere has not yet been identified. Here, we report the first observation of the polarization

Enhanced precipitation of magnetospheric energetic electrons during substorms increases ionospheric electron density and conductance. Such enhancements, which have timescales of a few hours, are not reproduced by the existing ionospheric models. We use the linear prediction filter (LPF) method to reconstruct the substorm-related response of electron densities and integral conductances from long-term

This study investigates the characterization and calibration of the high-energy electron experiments (HEP) instrument onboard the exploration of energization and radiation in geospace (ERG). Two detector modules, HEP-L and HEP-H, which employ stacks of multichannel silicon strip detectors, detect electrons in the energy ranges of 70 keV–1 MeV and 700 keV–2 MeV, respectively. The detector response to

A method for retrieving temperature and composition from 150 to 350 km in Earth's thermosphere using total number density measurements made via extreme ultraviolet (EUV) solar occultations by the Project for OnBoard Autonomy 2/Large Yield Radiometer (PROBA2/LYRA) instrument is presented. Systematic and random uncertainties are calculated and found to be less than 5% for the temperature measurements

The Small Payloads for Investigation of Disturbances in Electrojet by Rockets (SPIDER) sounding rocket was launched on February 2nd, 2016 (21:09 UT), deploying 10 free falling units (FFUs) inside a westward traveling auroral surge. Each FFUs deployed spherical electric field and Langmuir probes on wire-booms, providing in situ multi-point recordings of the electric field and plasma properties. The

Here we perform a statistical analysis of low frequency ultra-low-frequency (ULF) waves (mHz-Hz) in the Earth’s inner magnetosphere excluding electromagnetic ion cyclotron (EMIC) waves concurrently observed. We use the magnetic field data from the two Van Allen Probes during their first magnetic local time (MLT) revolution that cover the periods of coronal mass ejections. The major results of our analysis

In some polar coronal holes, previous studies have identified a coronal hole boundary layer (CHBL) which is different in composition from the coronal hole core region. However, compositionally distinct CHBL structure at low heliographic latitudes remains underexplored. Using solar wind composition measurements from the Advanced Composition Explorer (ACE), we study two particular low-latitude coronal