Second Remote Sensing of the Inner Heliosphere Workshop

Quasi-perpendicular waves in the dissipation range of the solar wind turbulence

Not scheduled

1m

Council Chamber, Old College (Aberystwyth University)

Speaker

Dr Xing Li (IMAPS, Aberystwyth University)

Description

The solar wind electric and magnetic field data from Cluster spacecraft is analysed to investigate the behaviour of the turbulence dissipation range. The dependence of both electric and magnetic field power spectra on wave number k can be categorised as several power laws: at relatively low wave number, the power index is about -5/3 indicating a turbulence inertial range. Beyond an inertial break point where kρ≤1 (ρ is proton gyro-radius), the power spectra become steeper and the subrange is often called turbulence dissipation (or dispersion) range. Eventually the spectra will flatten again at a second breakpoint. There is evidence that the electric field spectral power in the dissipation range is enhanced or not enhanced over the magnetic field spectral power at different observational time. We investigate the effect of the orientation of background magnetic field in the Geocentric Solar Elliptic coordinates and wave propagation on the observation of the turbulent electromagnetic field. Kinetic Alfven waves alone are generally unable to account for the spectra when the enhancement exists. Instead, quasi-perpendicular propagating fast magnetosonic waves are suggested to play a role in accounting for the enhancements.