Three-dimensional direct numerical simulations are implemented to investigate the energy cascade rate in compressible isothermal magnetohydrodynamic turbulence. Utilizing an exact law derived from the Kármán–Howarth equation, we examine the contributions of flux and nonflux terms to the cascade rate across a broad range of sonic and Alfvénic Mach numbers, from subsonic to supersonic regimes and with varying mean magnetic fields.
The Arctic is warming several times faster than the rest of the globe. Such Arctic amplification rapidly changes hydrometeorological conditions with consequences for the structuring of cold-adapted terrestrial and aquatic ecosystems. Arctic ecosystems, which have a relatively small buffering capacity, are particularly susceptible to hydrometeorological regime shifts thus frequently undergo system-scale transitions.
Coronal oscillations offer insight into energy transport and driving in the solar atmosphere. Knowing its polarization state helps constrain a wave’s displacement and velocity amplitude, improving estimates of wave energy flux and deposition rate. We demonstrate a method to combine imaging and spectral data to infer the polarization of a coronal loop’s standing kink wave, without the need for multiple instruments or multiple lines of sight.
Magnetic reconnection converts magnetic field energy into particle energy by breaking and reconnecting magnetic field lines. Magnetic reconnection is a kinetic process that generates a wide variety of kinetic waves via wave-particle interactions.
We report the detection of water vapor associated with main-belt comet 358P/PANSTARRS on UT 2024 January 8–9 using the NIRSPEC instrument on board JWST. We derive a water production rate of QH2O=(5.0±0.2)×1025 molecules s−1, marking only the second direct detection of sublimation products of any kind from a main-belt comet, after 238P/Read. Similar to 238P, we find a remarkable absence of hypervolatile species, finding QCO2<7.6×1022 molecules s−1, corresponding to QCO2/QH2O<0.2 %.
From late October to early November 2003, one of the strongest recorded geomagnetic storms occurred due to heightened solar activity. Three ground‐level enhancement events (GLEs) took place during this period, GLE 65, 66, and 67, known as the Halloween events.
The stability of weakly collisional plasmas is well represented by linear theory, and the generated waves play an essential role in the thermodynamics of these systems. The velocity distribution functions (VDFs) characterizing kinetic particle behavior are commonly represented as a sum of anisotropic bi-Maxwellians.
We present a comprehensive statistical analysis of ion-scale waves including dual-band ion-scale waves (DBIWs) observed by the Parker Solar Probe in the solar wind. DBIWs are characterized by the simultaneous occurrence of distinct left- and right-handed polarized wave packets at higher and lower frequencies, respectively, in the spacecraft frame, implying the presence of bidirectionally propagating L-mode waves.
Plasma-β is an important fundamental physical quantity in solar plasma physics, which determines the dominating process in the solar atmosphere, i.e., magnetic or thermodynamic processes. Here, for the first time, we provide variations of magnetic field and plasma-β along magnetically structured loops from the photosphere to the corona.
The near-Earth space environment is populated by the most energetic electrons with velocities very close to the speed of light, reaching ultra-relativistic energies. These electrons present a serious hazard to the Earth-orbiting spacecraft and are referred to as the Van Allen radiation belts. The question of how these particles are accelerated to such energies is still unanswered.