Preparing DKIST to characterize magnetic reconnection at the elemental scale

Montana State University, Bozeman MT

Investigators

Abstract

On the Sun, solar flares release magnetic energy very quickly using a process called magnetic reconnection. This grant will develop and use a method of studying the magnetic reconnection driving a solar flare. The investigators will simulate solar flares powered by magnetic reconnection, and test the reality of these simulations against measurements made by the Interface Region Imaging Spectrograph (IRIS) spacecraft now studying the Sun. The new method they develop will be ready to analyze observations of the solar chromosphere made at much greater resolutions by the new Daniel K. Inouye Solar Telescope (DKIST) when it begins operation. This project supports the mission of the NSF by promoting our understanding of magnetic field structure and activity at the Sun. The research will contribute to the doctoral thesis of a physics graduate student supervised directly by the investigators. The investigators will measure the reconnection characteristics indirectly, using spectroscopic observations of the solar transition region and chromosphere, where high spatial resolution and rapid time cadences are possible, using far ultraviolet measurements made by the IRIS spacecraft. They will develop numerical simulations of flaring loops energized by reconnection to compute the downward flows generated in the transition region and chromosphere. They will then test and calibrate these computations using existing spectroscopic observations of flare ribbons made by IRIS. Future observations using the DKIST Visible Spectropolarimeter and the Visible Tunable Filter instruments each measure different lines of Ca II which, in flare ribbons, will contain information about the energy release by flare reconnection. The calibrated model will be used with these data to measure solar flare magnetic reconnection at the smallest scales yet resolved. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.