Nonlinear dynamics of space and astrophysical plasmas

Solar atmosphere and solar wind provide a unique laboratory for understanding the nonlinear dynamics of space and astrophysical plasmas. First, we present the observational evidence of two magnetically reconnected current sheets in the vicinity of a turbulent front magnetic cloud boundary layer, and discuss the relation between current sheets, turbulence, and magnetic reconnections at the leading edge of an interplanetary coronal mass ejection detected by Cluster spacecraft. Next, we report the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetary magnetic flux ropes are identified using ACE, Wind and Cluster spacecraft. A quantitative analysis of the reconnection condition and the degree of intermittency reveals that rope–rope magnetic reconnection is the most likely site for genesis of interplanetary intermittency turbulence in this event. The dynamic pressure pulse resulting from this reconnection triggers the onset of a geomagnetic storm. Finally, we present the simultaneous observation of an erupting coronal loop  by the Nançay radioheliograph, the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory, and the hard X-ray detector of the Reuven Ramaty High-Energy Solar Spectroscopic Imager, which shows that the type-II solar radio bursts can be emitted from both upstream and downstream of the shock wave front.

09/05/2019 - 12:30
Prof. Abraham Chian
University of Adelaide, Australia