A5079432117- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Solar Radiation and Photovoltaics
Imperial College London
2023-2024
Abstract Plasma in Earth's magnetosheath rarely experiences interparticle collisions, so kinetic microinstabilities are thought to contribute regulating the plasma thermodynamics. Instabilities excite waves and redistribute free energy velocity space, reducing distribution function (VDF). Using 24 hr of data spread over 163 intervals situ observations by Magnetospheric Multiscale (MMS), we investigate signatures conversion where turbulent dynamics have locally distorted VDFs into...
Turbulence is ubiquitous within space plasmas, where it associated with numerous nonlinear interactions. Magnetospheric Multiscale (MMS) provides the unique opportunity to decompose electric field (E) dynamics into contributions from different linear and processes via direct measurements of terms in generalized Ohm's law. Using high-resolution multipoint measurements, we compute magnetohydrodynamic (EMHD), Hall (EHall), electron pressure (EPe), inertia (Einertia) for 60 turbulent...
Plasma in the terrestrial magnetosheath is characterised by very weak particle-particle collisions, so kinetic microinstabilities are thought to be responsible for regulating thermodynamics of plasma. By exciting electromagnetic waves, these instabilities redistribute free energy velocity space, moulding distribution function (VDF) into a lower state. In high-beta magnetosheath, relatively small perturbations VDF can easily excite compared low-beta inner heliosphere. Since magnetic fields...
Magnetic reconnection has long been thought to play an important role in turbulent plasmas – with the nonlinear dynamics of systems being well known self-consistently generate intense current structures and associated magnetic shears that can be sites where so-called turbulence-driven occur. However, complex three-dimensional topologies small-scale nature these events have traditionally made it challenging assess from either a numerical or observational perspective. Recent...
Turbulence is a complex phenomenon whereby fluctuation energy transferred between different scale sizes as result of nonlinear interactions. Electromagnetic turbulence ubiquitous within space plasmas, wherein it associated with numerous The dynamics the magnetic field, which are widely studied in theory, intimately linked to electric controls exchange field and particles. Magnetospheric Multiscale (MMS) provides unique opportunity decompose into contributions from linear processes. evolution...
We model plasma turbulence in the near-Sun solar wind by means of a high-resolution fully kinetic simulation initialised with average conditions measured Parker Solar Probe during its first encounter. Once is developed, power spectra and electromagnetic fluctuations exhibit clear power-law intervals down to sub-electron scales. Our models electron-scale electric field unprecedented accuracy. This allows us perform detailed analysis different terms generalised Ohm's law (MHD, Hall, electron...