My research in solar physics began when I accepted an offer for an NSF Research Experience for Undergraduates (REU) at the National Solar Observatory (NSO) in Tucson, Arizona. The goal of my project was to constrain theoretical models of energy transport mechanisms in the sun leading to explosive events like coronal mass ejections and solar flares. We examined the helicity injection from the subphotospheric plasma to the photospheric magnetic field in active regions.
We published A COMBINED STUDY OF PHOTOSPHERIC MAGNETIC AND CURRENT HELICITIES AND SUBSURFACE KINETIC HELICITIES OF SOLAR ACTIVE REGIONS DURING 2006–2013 (Seligman, Petrie & Komm 2014), in which we compared the average photospheric current helicity Hc, photospheric twist parameter α (a well-known proxy for the full relative magnetic helicity), and subsurface kinetic helicity Hk for 194 active regions observed between 2006–2013. We use 2440 Hinode photospheric vector magnetograms, and the corresponding subsurface fluid velocity data derived from GONG (2006–2012) and Helioseismic and Magnetic Imager (2010–2013) dopplergrams. We found a significant hemispheric bias in all three parameters. Subsurface fluid motions of a given handedness correspond to photospheric helicities of both signs in approximately equal numbers. However, common variations appeared in annual averages of these quantities over all regions. Furthermore, in a subset of 77 regions, we found significant correlations between the temporal profiles of the subsurface and photospheric helicities. In these cases, the sign of the linear correlation coefficient matched the sign relationship between the helicities, indicating that the photospheric magnetic field twist was sensitive to the twisting motions below the surface.