Abstract
Current magnetohydrodynamics (MHD) models largely rely on synoptic
magnetograms, such as the ones produced by the Global Oscillation
Network Group (GONG). Magnetograms are currently available mostly from
the front side of the Sun, which significantly reduces the accuracy of
MHD modeling. Extreme Ultraviolet (EUV) images can instead be obtained
from other vantage points. This study explores the possibility of using
EUV information from the Atmospheric Imaging Assembly (AIA) to directly
generate the input for the state-of-the-art 3D MHD model European
Heliospheric FORecasting Information Asset (EUHFORIA). Towards this
goal, we develop a method called Transfer-Solar-GAN which combines a
conditional generative adversarial network with a transfer learning
approach to overcome training dataset limitations. The source domain
dataset is constructed from multiple pairs of the central portion of
co-registered AIA and Helioseismic and Magnetic Imager (HMI) line of
sight (LOS) full-disk images, while the target domain is constructed
from pairs of portions of AIA and GONG sine-latitude synoptic maps that
we call segments. We evaluate Transfer-Solar-GAN by comparing modeled
and measured solar wind velocity and magnetic field density parameters
at the L1 Lagrange point and along the Parker Solar Probe (PSP)
trajectory which were determined with EUHFORIA using both empirical GONG
and artificial-intelligence (AI)-synthetic synoptic magnetograms as
inputs. Our results demonstrate that the Transfer-Solar-GAN model can
better provide the necessary information to run solar physics models by
EUV information. Our proposed model is trained with only hundreds of
paired image segments and enforces a reliable data division strategy.