Power spectral anisotropy in wave-vector space of solar wind turbulence at ion kinetic scales determined by phase-differencing technique
Owen Roberts (ESA), Lloyd Woodham (Aberystwyth University), Quanming Lu (University of Science and Technology of China)
Aberystwyth University
Using Cluster magnetic field data, we adopt wavelet analysis and multi-point phase-differencing techniques to study the solar wind turbulence at ion kinetic scales. We are able to determine the power anisotropy in wave-vector space using tens of thousands of wave packets simultaneously observed by four
Cluster spacecraft. Similar to the results of previous k-filtering analysis, we found that the turbulence power is rested in wave vectors dominantly in directions nearly perpendicular to the scale dependent mean magnetic field. The phase-differencing technique further reveals a very weak and quasi-parallel propagating turbulence component, at least in some of the fast solar wind cases we studied. Previous k-
filtering results did not find such weak component. When its presence was revealed by magnetic helicity analysis, the power of the component however was unknown.


09:00 - 10:30
BS - A26 (40)