Collaborative Research: SHINE: Observational and Theoretical Studies of the Parametric Decay Instability in the Lower Solar Atmosphere

It is unclear how the outer layer of the Sun, the corona, is heated to millions of degrees. One potential mechanism is through the parametric decay instability (PDI). This project addresses the Solar, Heliospheric, and Interplanetary Environment (SHINE) goal of understanding the solar corona through numerical simulations and analysis of space-based and NSF-funded ground based solar observations. The project also supports outreach activities in New York City and New Mexico. Two post-doctoral researchers will be supported, along with undergraduate students at Columbia University.The project will determine whether PDI is an important process in the solar atmosphere. The team will analyze observations from the Coronal Multichannel Polarimeter, the Extreme Ultraviolet Imaging Spectrometer, the Interface Region Imaging Spectrometer, and the NSF-funded Daniel K. Inouye Solar Telescope. Numerical modeling will be used to better understand the behavior of PDI in the presence of gradients in the plasma properties of the transition region and the corona. Magnetohydrodynamic simulations will be carried out to study Alfven waves and PDI growth in the lower solar atmosphere, where the scale length of gradients is smaller than the wavelength. This is critical to understand how density fluctuations are generated very close to the Sun. Moreover, ion heating associated with acoustic waves produced by PDI will be investigated using hybrid simulations, to estimate what fraction of the Alfven wave power can be dissipated in the lower atmosphere.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.