Periasamy K. Manoharan, Mr. - PhD
Radio Astronomy Centre, National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, India
       
       
Session 1 - Speaker

Radial Evolution of Coronal Mass Ejections in the Inner Heliosphere

P.K. Manoharan, Radio Astronomy Centre, National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, India
       

Coronal mass ejections (CMEs) are the most energetic events associated with the eruption of plasma and magnetic field from the Sun and they drive solar wind disturbances, accelerate particles to high energies, and contribute to space weather phenomena affecting the near-Earth environment, e.g., severe geo-magnetic storms. In understanding the range of space weather effects of a CME, the knowledge of the radial evolution of the CME is important for the determining of its arrival at the near-Earth space and for inferring of its interaction with the disturbed/ambient solar wind in the course of its travel to 1 AU and further. The interplanetary scintillation (IPS) technique provides an essential tool to track CMEs and their associated disturbances in the Sun-Earth distance, and it has demonstrated the ability to make correct association between CMEs and their effects at the Earth's environment. The IPS measurements at 327 MHz obtained from the Ooty Radio Telescope (operated by the National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, India) are capable of providing estimates of solar wind speed and density turbulence along directions of a large number of radio sources (~1000 sources per day) in the heliospheric distance range of 20 - 250 solar radii. This talk will review results on the radial evolution of CMEs based on the large IPS database collected from the Ooty Radio Telescope. Additionally, the solar wind estimates along different cuts of the heliosphere allow the reconstruction of three-dimensional structures of propagating transients in the inner heliosphere. The results on three-dimensional evolution of size and speed of solar wind transients (e.g., propagating CMEs as well as co-rotating interaction regions (CIRs)), are reviewed and discussed on the possibility of forming a basic model to forecast the arrival/impact of solar and solar wind generated space weather effects at the Earth or else where.