English

Predicting the thermodynamics in the chromosphere from the translation of SDO data into the IRIS$^{2}$ inversion results using a visual transformer model

Solar and Stellar Astrophysics 2026-04-24 v1

Abstract

We present SDO2IRIS2^2: a visual transformer model that translates a combination of images of the chromosphere and transition region (TR), observed by AIA, and a line-of-sight magnetogram, provided by HMI, into temperature, line-of-sight velocity (vlos_{los}), velocity of the turbulent motions (vturb_{turb}), and electron density (ne_{e}) in the chromosphere. Using the thermodynamic variables obtained from the inversion of the chromospheric lines Mg II h&k, observed by IRIS, as the target of the model, and the intensity images in the chromosphere and TR, and the photospheric magnetogram as the input, the predicted T and ne_{e} show a strong correlation (0.80\approx 0.80) for \approx80% of the test inverted data, a moderate-to-strong correlation (0.63\approx0.63) for 70% of the vturb_{turb} of the target test inverted data, while for the vlosv_{los}, the correlation is weak. Therefore, the predicted values by SDO2IRIS2^2 may be used as an estimation of the thermodynamics in the chromosphere, either as a stand-alone result or as complementary information to other chromospheric data observed simultaneously. The execution time employed by SDO2IRIS2^2 to obtain the thermodynamic values in the chromosphere is of the order of a few minutes, being 10\le10 minutes when using a CPU, and 5\le5 minutes when using a GPU. SDO2IRIS2^2 opens a new avenue for the use of SDO data thanks to the inversions provided by IRIS observables.

Keywords

Cite

@article{arxiv.2604.21184,
  title  = {Predicting the thermodynamics in the chromosphere from the translation of SDO data into the IRIS$^{2}$ inversion results using a visual transformer model},
  author = {Alberto Sainz Dalda and Vishal Upendran and Juno Kim and Kyuhyoun Cho and Paul S. Killam and Viggo Hansteen and Bart De Pontieu},
  journal= {arXiv preprint arXiv:2604.21184},
  year   = {2026}
}

Comments

21 pages, 6 figures, and 7 tables