Analyzing and Modeling the Shear of

Post-Reconnection Flare Loops

Allison Snyder with Dr. Jiong Qiu

Solar Physics REU 2023

Montana State University

About Me

My name is Allison Snyder, and I am a rising junior at Mount Holyoke College. I have loved both physics and astronomy since I grew out of my volcano phase at age 5. I love diving into research and working on new ideas that challenge my understanding of the world. Discovering something new or creating a program that works is always worthwile. In my free time, I like to go on hikes in the woods, read epic fantasy novels, and craft conlangs. My cat, Tutu (yes, named after the ballet skirt), wishes I spent more time sleeping at home and snuggling with her.

REU Project

This summer (2024), I'm working with Dr. Jiong Qiu to explore the 3D structure of post-reconnection flare loops and how the magnetic structure, specifically the shear, compares to the potential field by tracing thousands of loops.

Past Research

Fall 2020- Spring 2021: I Investigated the effects of adding mycorrhizae in Martian regolith on Lactuca sativa growth. This independent research project was pressented at the 2021 Synopsys Science Fair.

Fall 2021- Spring 2022: I measured the Zeeman Splitting on Alpha Centauri B in order to track how magnetic fields changed over the course of its stellar cycle. This independent research project was presented at the 2022 Synopsys Science Fair and won an honorary mention.

Fall 2023 - Spring 2024: I assisted Professor Smith at Mount Holyoke College in developing a model for bacterial movement to analyze how collective motion relates to mixing.


Contact me at: snyde23a@mtholyoke.edu or allisonsnyder03@gmail.com

Research Project

Allison Snyder, Dr. Joing Qiu

THE SUN

My research project this summer was to investigate solar flares. Solar flares are caused by magnetic reconnection where magnetic field lines reconnected releasing energy observed as solar flares. When the loops reconnect, they have been observed to do so at an angle relative to the polarity inversion line (PIL) that divides the positive and negative magnetic flux in the Sun's photosphere. The complementary angle between the flare loop and the PIL is known as the shear. Past observations of solar flares have observed a trend of strong-to-weak shear as the flares progress. However, there have been few quatitative studies of how each loop behaves over time and space. The goal of my summer research was to get a quantitative analysis of many loops' shear in a flare.

My work analysed an X 1.0 flare that occured on October 28th, 2021 as it was observed by the Solar Dynamic Observatory (SDO). I used the OCCULT program to trace linear structures, such as the flare loops that were seen in SDO's AIA images. Then the angles of these loops with the PIL were meansured over time in three wavelengths. The AIA wavelengths used were 94A, 335A, and 171A because these bandpasses were not saturated and covered a variety of temperatures. The shear was analysed as a function of time from over 25,000 loops.

Finally, the traced loops were compared to magnetic models. A model of a flare is unhelpful if it cannot accurately capture the behavior of a flare. The traced flare loops were compared to a potential field model and several linear force free models. However, none of the models captured the behavior of all of the loops even though some of the linear force free models appeared to match some of the loops. This suggests that a more advanced magnetic model must be developed to capture the behavior of loops.

References

Warren, H. P., Crump, N. A., Ugarte-Urra, I., Sun, X., Aschwanden, M. J., & Wiegelmann, T. (2018). Toward a quantitative comparison of magnetic field extrapolations and observed coronal loops. The Astrophysics Journal, 860(1) 46.

Qiu, J., Alaoui, M., Antiochos, S. K., Dahlin, J. T., Swisdak, M., Drake, J. F., Robison, A., DeVore, C. R., & Uritsky, V. M. (2023). The role of magnetic shear in reconnection-driven flare energy release. The Astrophysics Journal, 955(1) 34.

Aschwanden, M. J. (2010). A code for automated tracing of coronal loops approaching visual perception. Solar Physics, 262(2) 399-423.