CINECA IRIS Institutional Research Information System
IRIS è la soluzione IT che facilita la raccolta e la gestione dei dati relativi alle attività e ai prodotti della ricerca. Fornisce a ricercatori, amministratori e valutatori gli strumenti per monitorare i risultati della ricerca, aumentarne la visibilità e allocare in modo efficace le risorse disponibili.
EnglishSpacecraft observations show the presence, in the polar Solar Wind (SW) plasma, of outward propagating Alfvénic fluctuations with a very broadband spectrum. This is true only up to a certain frequency in the spectrum, after which a consistent amount of energy is present also in the spectra of inward propagating Alfvén and density fluctuations. A mechanism able to explain the production of inward propagating modes and density fluctuations is the parametric instability, in which Alfvén waves can decay and produce back-scattered waves and density perturbations. In this work, we show some recent results obtained with a (2+1/2)D-MHD pseudo-spectral numerical code in which an attempt is made to reproduce an initial condition similar to that observed in the real SW. The evolution of the instability generates a nonlinear cascade that redistributes the energy towards the small scales in all directions. A striking feature of this evolution is the presence of a few localized, energy containing, coherent pressure-balanced structures.
Scheda prodotto non validato
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo
| Titolo: | Parametric instability and turbulent cascades in space plasmas |
| Autori: | |
| Data di pubblicazione: | 2019 |
| Serie: | |
| Handle: | http://hdl.handle.net/20.500.11770/305787 |
| Appare nelle tipologie: | 2.1 Contributo in volume (Capitolo o Saggio) |
File in questo prodotto:
Copyright © 2021