Physics Dept Seminar

March 31, Monday

The Role of Radio Observations in Remote Sensing Magnetic Fields of Solar Eruptions from the Corona to the Heliosphere

Dr. Devojyoti Kansabanik

Johns Hopkins University Applied Physics Laboratory

(Solar Physics, Host: Gary)

Time: 11:45 am - 12:45 pm with 11:30 am teatime

Room: ECE 202

The solar corona, a dynamic and magnetized plasma environment, evolves and accumulates energy through stress in the magnetic fields built due to differential solar rotation. This energy is released via solar flares, solar energetic particles (SEPs), and large-scale plasma expulsions known as coronal mass ejections (CMEs), shaping space weather in the heliosphere. Magnetic fields govern these processes, from the onset of eruptions to particle acceleration and geo-effectiveness. However, their routine measurement is limited to the solar surface and certain vantage points in space through in-situ spacecraft observations, while intermediate regions rely on models. Radio observations uniquely offer observational diagnostic tools for estimating magnetic fields in the solar corona and inner heliosphere, spanning eruption sites to interplanetary space. Advances in radio instrumentation and computational capabilities, along with state-of-the-art algorithms, have led to high-fidelity spectropolarimetric imaging with new-generation radio interferometers, enabling the remote sensing of plasma properties of these solar eruptions.

This talk will focus on some of the radio observational probes used to estimate magnetic fields and other plasma properties of solar eruptive events from the corona to the inner heliosphere. I will highlight key achievements to date, present some initial results from ongoing efforts, and discuss future directions for integrating these observations into the space weather forecasting framework. I will take you on a journey from tackling instrumental challenges to modeling observations that have led to significant advancements in measuring CME magnetic fields at coronal heights. I will then showcase ongoing efforts to utilize indirect background radio sky observations, which have successfully provided observational proxies for CME magnetic fields in the inner heliosphere. Next, I will discuss the necessity of a global network of new-generation solar-dedicated and general-purpose radio arrays as a crucial step in incorporating these observational probes into space weather forecasting. I will outline current efforts and future plans to materialize this concept. Finally, I will discuss approaches that may be taken in the future to address the currently existing gaps — ranging from operational and observational challenges to modeling strategies — to facilitate the transition from research to operational space weather forecasting using this unique radio observational capability.