I am a solar physics researcher, Maui based. My research interests are,
The solar coronal heating puzzle, contrasted with measured inputs, e.g., the heating power expression based on observed quantities.
Magnetic topology and reconstruction of the solar corona, e.g., the magnetic helicity calculation, searching for a null point, separatrix, and separator, and computing the quasi-separatrix layer.
MHD instabilities that trigger eruptions, e.g., the kink instability related to the twist number before and after eruption.
Solar and stellar flares model and statistics.
Spectropolarimetric inversion and post-processing for solar lower atmospheric observations. Currently works on the DKIST VISP data.
In the study “A Possible Mechanism for ‘Late Phase’ in Stellar White-Light Flares”, we explore the unique brightness pattern of M-dwarf star flares observed by the TESS satellite: a sharp peak followed by a slower secondary one. We see similar patterns in our Sun due to long hot gas loops distinct from main flare sites. Inspired by these solar patterns, our simulations for star flares suggest that post-flare, the gas in these loops becomes dense, causing them to shine brightly, consistent with TESS observations. The longer these loops evolve, the more distinct the second brightness peak becomes, indicating more flare energy. We theorize that this dense gas in the post-flare loops might account for these unique brightness patterns.
Our Spectropolarimetric Inversion in Four Dimensions with Deep Learning (SpIN4D) project aims to develop deep convolutional neural networks to estimate the solar photosphere’s physical properties based on the spectropolarimetric observations from NSF’s Daniel K. Inouye Solar Telescope (DKIST). We have performed a series of MURaM radiative MHD simulations for a quiet-Sun model with various mean magnetic field strengths, accumulating 85 TB of atmospheric data and 20.1 TB of synthetic spectra. As one of our validation efforts, we obtained high-resolution, multi-line observations for a plage region using the Visible Spectro-Polarimeter (ViSP) instrument on DKIST, and compared the data with the MHD simulation. Employing Stokes inversion techniques via both LTE and non-LTE codes (SIR and DeSIRe), we analyzed several spectral lines (Fe I 630 nm pairs, Na D I 589.6 nm, Fe I 589.2 nm, and Ni I 589.3 nm) whose formation heights range from the photosphere to the lower chromosphere. Atmospheric parameters, including magnetic field strength, electron pressure, and temperature across varied layers, were statistically assessed against MURaM simulations at corresponding optical depths.