Abstract Details

Name: Ranadeep Sarkar
Affiliation: University of Helsinki
Conference ID: ASI2021_473
Title : Solar Origin of Space Weather
Authors and Co-Authors : Ranadeep Sarkar
Abstract Type : Oral
Abstract Category : Thesis
Abstract : Coronal mass ejections (CMEs), the gigantic clouds of magnetized plasma that routinely erupt from the Sun, are recognized as one of the major solar origins of space weather disturbances. If the magnetic field inside an Earth-directed CME has a component (Bz) opposite to Earth's magnetic field, then it can lead to severe geomagnetic storms. Therefore, it is crucial to predict the strength of Bz inside an Earth impacting interplanetary CME (ICME). Based on the observational and modelling efforts, in this thesis, we explore the origin and evolution of CMEs aiming to forecast its space weather impact on Earth. Our studies on the source region characteristics of CMEs reveal the conditions leading to CME eruptions and also carry significant implications for the forecasting of recurrent large eruptive events from the same AR and hence the chances of interaction between the associated CMEs. Our studies on the CME initiation in lower corona and its subsequent evolution in interplanetary space provides the important observational constraints on the CME evolution. Combining the knowledge of CME evolution and its near-Sun properties, we developed a model, the INterplanetary Flux ROpe Simulator (INFROS), which shows promising results in forecasting of Bz in real time and is advantageous in many aspects compared to the existing Bz forecasting models. The novel techniques to predict the magnetic field vectors of ICMEs as explored in this thesis build the stepping stones towards the forecasting of intensity of the associated geomagnetic storms at near-Earth space.