Reconstruction of Quiet and Transient Solar Wind Structures in the Inner Heliosphere

In this talk, I will discuss results of three-dimensional evolution of the solar wind density and speed in the inner heliosphere. The primary solar wind data sets used in these studies have been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope (India), which is capable of measuring scintillation of a large number of radio sources per day and solar wind estimates along different cuts of the heliosphere, allow to image the three-dimensional structure of the ambient solar wind and propagating transients, such as coronal mass ejections (CMEs) and/or co-rotating interaction regions (CIRs) in the inner heliosphere. Results indicate that the interaction between the CME (or the CIR) and the background solar wind determines the radial evolution of its speed and size. Ooty studies play a key role in quantifying the drag force imposed on disturbances by the solar wind interaction, which is essential in modeling the propagation characteristics of disturbances within 1-AU heliosphere. Solar wind structures obtained from the IPS observations have also been compared with in-situ measurements obtained from the near-Earth space missions. Such studies have a great importance in understanding the prediction of CME/CIR-associated space weather at near-Earth space.