Listed are all scientific papers resulting from an ISSI activity written or co-authored by ISSI Team members, Working Group members, Workshop participants, visitors or staff members.
Three substorm events in which Defense Meteorological Satellite Program (DMSP) spacecraft are geomagnetically co‐located with substorm onset locations in IMAGE far ultraviolet auroral images are analyzed. A Hilbert‐Huang Transform is used to decompose the DMSP B⊥ ${B}_{perp }$ in the ionosphere to its intrinsic mode functions.
Context. The energy spectra of energetic particles offer valuable insights into particle acceleration processes. While the commonly observed spectral breaks in solar energetic electron (SEE) spectra could serve as fingerprints of the acceleration process, several transport-related effects have been proposed to be responsible as well.
Saturn’s moon Titan exhibits remarkable parallels to the Earth in many geophysical and geological processes not found elsewhere in the solar system at the present day. These include a nitrogen atmosphere with a condensible gas—methane—replacing the Earth’s water, leading to an active meteorology with rainfall and surface manifestations including rivers, lakes and seas, and the dissolution of karstic terrain.
On December 2023, the Juno spacecraft made a flyby of Io above the northern hemisphere at a closest approach (CA) altitude of ∼1,500 km (PJ57). The Juno/Waves and Radio‐occultation measurements showed a surprising large electron density ∼28,000 cm−3 near closest approach. We run 2D numerical simulations of the plasma/atmosphere interaction to explore the causes of this high plasma density.
Collisionless plasma shocks are a common feature of many space and astrophysical systems. They are sources of high-energy particles and nonthermal emission, channeling as much as 20% of the shock’s energy into nonthermal particles. The generation and acceleration of these nonthermal particles have been previously studied and shown to affect shock hydrodynamics to the zeroth order.
In the Earth’s magnetotail bursty bulk flows are often associated with dipolarizing magnetic flux bundles. The leading edges of such earthward‐moving flux bundles are called dipolarization fronts (DF). In the present study we investigate the characteristics of ion‐scale oscillations embedded inside DFs, using observations from NASA’s Magnetospheric Multiscale mission (MMS) between 2017 and 2022.
Spatially resolved X-ray observations are the key to understanding electron acceleration in solar flares. Currently, the underlying processes that efficiently energize solar flare particles are poorly constrained. Abundant flare observations suggest that turbulence plays a crucial role in transferring energy between the magnetic field and energetic electrons.
Context. Previous studies have shown that a streamer blob might originate in the lower corona and thus be affected by activity in that region. While the base of one streamer might differ from that of another, it can be cataloged into two distinct types: active region streamers (ARSs) that have active regions at their base, and quiet equatorial streamers (QESs) that do not have an active region underneath. The difference between the blob properties in ARSs and those in QESs remains unknown.
The Autonomous Adaptive Low‐Power Instrument Platform magnetometer chain located in Antarctica has been operating since 2016 at a magnetically conjugate location to the West Greenland magnetometer chain, enabling interhemispheric evaluations of geomagnetic phenomena.
Minor ions are preferentially heated and accelerated in the solar coronal holes (CHs). It remains unclear how ion energization varies across the Alfvén critical surface (ACS). This work reports the variation in the temperature and the flow speed of protons and α particles from 10 solar radii (R⊙) to 0.2 au in solar cycle 25. The α–proton differential speed normalized to the local Alfvén speed (vαp/vA) increases significantly beyond the ACS. Since vA decreases, vαp decreases with distance.
