7422 20250123153025.0 SEMIN-2025-0021 Deshpande, Ketaki Electron Density Mapping: Insights from Radio and In-Situ Observations & EUHFORIA Modeling 2025 2025-01-10 Mapping the coronal electron density remains a challenging task, as we still rely on rather old 1D electron density models, most of which are derived from remote sensing observations and lack validation with in situ measurements. The novel observations from Parker Solar Probe (PSP) provide a unique opportunity to validate these models and enhance space weather modeling capabilities. In this study, we analyze type III radio bursts observed during PSP’s second perihelion. By employing radio triangulation, we estimate the 3D radio source positions and map the electron densities along the burst propagation path. These results are then compared with in situ electron density measurements from PSP. Additionally, we use EUHFORIA (European Heliospheric Forecasting Information Asset) to model electron densities at the PSP location and the radio source positions. Our findings indicate that bursts occurring within a few minutes from the same source can exhibit significantly different propagation paths. A comparison between radio-derived and in situ densities reveals a discrepancy of one order of magnitude. We also perform simulations using GONG and ADAPT-GONG magnetic maps as input. Both simulations suggest that type III bursts propagate along higher-density regions; however, results obtained with ADAPT-GONG maps show a better match with PSP in situ densities and predict higher density values overall. These results highlight the importance of validating remote sensing electron density models with in situ observations and demonstrate the impact of different magnetic field inputs on space weather modeling. The improved agreement with ADAPTGONG maps suggests that incorporating more dynamic and data-driven models can enhance the accuracy of electron density estimations, ultimately improving our understanding of solar wind structures and radio wave propagation in the heliosphere. 3BOURSE_DESHPANDE/ 3BOURSE_DESHPANDE/ 3BOURSE_DESHPANDE STCE Udaipur Solar Observatory (USO), India ketaki.deshpande@ksb-orb.be SEMIN