| Authors : | Ketaki Deshpande1,2, Jasmina Magdalenic1,2, Immanuel Christopher Jebaraj3, Senthamizh Pavai Valliappan1, Vratislav Krupar4,5 |
| Authors Affiliation: | 1. Ketaki Deshpande, Jasmina Magdalenic, Senthamizh Pavai Valliappan, Solar-Terrestrial Centre of Excellence – SIDC, Royal Observatory of Belgium, Avenue Circulaire 3, 1180 Uccle, Belgium
2. Ketaki Deshpande, Jasmina Magdalenic, Center for mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, 3001 Leuven, Belgium
3. Immanuel Christopher Jebaraj, Space Research Laboratory, University of Turku, FI- 20014 Turun yliopisto, Finland
4. Vratislav Krupar, Goddard Planetary Heliophysics Institute, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
5. Vratislav Krupar, Heliospheric Physics Laboratory, Heliophysics Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA |
| Abstract : | Accurately mapping the coronal electron densities, all the way from the Sun into the interplanetary space, has number of a long-discussed challenges. While radio observations offer possibility to direct estimate the coronal electron density, the validation of accuracy of this estimation against in-situ measurements has been hindered by the lack of the near-Sun in situ observations. The novel Parker Solar Probe (PSP) mission finally provides an opportunity for such validation.
The focus of this study is on the type III radio bursts observed during the second PSP perihelion. Type III bursts are radio signatures of the fast electron beams tracing open or quasi-open magnetic field lines and mapping the ambient plasma density. Employing direction finding data from the two observing points and radio triangulation method, we determine the 3D radio source positions in the solar corona. These radio source positions allow us to map the electron densities using the relationship between plasma frequency and electron density.
After we estimated the radio source positions and the local coronal electron densities, we compared the radio-derived densities with in-situ measurements from the PSP. Additionally, we also obtained the coronal electron densities at both, the radio source and the PSP's location, by utilizing the EUHFORIA (European Heliospheric FORecasting Information Asset) space weather forecasting model.
The first results showed that the densities obtained with radio observations are somewhat higher than the in-situ density mapped by the PSP. The modelled density at PSP position was improved and the new result agrees with the observations after changing the PFSS source surface radius to 2.9 and 3.0 Rs.
|
