Advancing Current Determination in the Chromosphere

• Applicant: Dr. Juan Manuel Borrero
• Subject Area: Astrophysics and Astronomy ; Atmospheric Science
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 538773352

Electric currents play a very important role in the solar atmosphere. They are crucial for its energy balance and they can be employed as proxies of regions where the solar magnetic field is highly non-potential and therefore likely to cause transient and explosive events such a flares and coronal mass ejections. These events can have disastrous consequences in Earth's upper atmosphere and cause disruptions in satellite communications, GPS tracking and delays and rerouting of polar flights. Consequently, measuring electric currents has been long considered one of the most important goals in solar physics, and a primary objective for the new generation (4-meter class) of solar telescopes such as DKIST and EST. The objective of this proposal is to improve our ability to infer electric currents in the solar chromosphere. This will be done by improving our Stokes inversion code to include physical effects such as advection in the momentum equation and non-Local Thermodynamics Equilibrium effects in the solution to the radiative transfer equation for polarized light. The former objective will be achieved by obtaining the full velocity vector via a solution to the induction equation in ideal magneto-hydrodynamics. The latter will be achieved by solving the statistical equilibrium equations that provide the atomic level populations in spectral lines formed in the chromosphere.

• DFG Programme: Research Grants
• International Connection: Sweden, USA
• Co-Investigator: Dr. Ivan Milic
• Cooperation Partners: Professorin Dr. Maria Kazachenko; Dr. Adur Pastor Yabar