RADIO-LOUD CME-CME POTENTIAL INTERACTIONS IN SOLAR CYCLE 24 IN THE YEARS 2009-2018

Abstract

Radio loud (RL) CMEs are those associated with solar type II radio bursts. These CMEs might interact with each other on their way from the solar surface to the interplanetary medium. As a result ,these CMEs leave a radio signature on the dynamic spectrum and bright white enhancement on the white-light images. In this research ,we have found a total set of 32 possible interacting CMEs and 16 associated DH type II bursts are registered on the NASA SOHO/LASCO CDAW catalogue for the period spanning from 2009 to 2018. However , only the DH component of the radio bursts were considered. This possibility of interaction was estimated by a thorough investigation of the origins of the CMEs and the simultaneity of enhancement on the CMEs difference images on the LASCO field of view and the intensification of the burst on the dynamic spectrum of the Wind/WAVES. A primary CME is mainly emitter of the DH burst and the preceding interacts with it. By tracking the whitelight images of these CMEs ,the height-time diagrams are obtained. Our results show that most of the primary CMEs are halo and averagely much faster (1482.3 kms-1) than the preceding CMEs (841.6 kms-1). More over ,drift rate of DH type IIs ,time duration of pre and pri-CMEs and interaction height are found to be 1.82 MHzs-1 , ∼34.6 min and ∼5.3 Ro ,respectively. The pre-CMEs are found to be less energetic than the primary CMEs. Most of the interacting CMEs were originating from the western regions of the Sun. Studying the properties of interacting RL CMEs and their kinematics are important to be able to make predications before a CME arrival and make proper arrangements both on the ground and in space.