Saved in:
Bibliographic Details
Main Authors: Samara, Evangelia, Provornikova, Elena, Arge, C. Nick, McCubbin, Andrew, Merkin, Viacheslav G.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2509.20575
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914054523584512
author Samara, Evangelia
Provornikova, Elena
Arge, C. Nick
McCubbin, Andrew
Merkin, Viacheslav G.
author_facet Samara, Evangelia
Provornikova, Elena
Arge, C. Nick
McCubbin, Andrew
Merkin, Viacheslav G.
contents We explore the capabilities of time-dependent (TD) magnetohydrodynamics (MHD) solar wind simulations with the coupled WSA model of the solar corona and GAMERA model of the inner heliosphere. We compare TD with steady state (SS) simulations and with in situ data from multiple spacecraft (Earth, STEREO-A, PSP). We show that TD predictions, although better than SS predictions, substantially mispredict the solar wind at different heliospheric locations. We identified three reasons for that: (1) the uncalibrated WSA velocity formula used to generate solar wind velocities at the inner boundary of a heliospheric domain, (2) the extraction of the WSA boundary conditions for input into MHD models very high in the corona, and (3) the abrupt and partial emergence of active regions from the solar east limb. Evaluation of one year of TD predictions at Earth and STEREO-A locations shows that by tuning accordingly the WSA relationship when used with MHD models, and by extracting the WSA boundary conditions lower in the corona (at 5 Rs instead of 21.5 Rs), can lead to improved predictions. However, the abrupt emergence of active regions from the east limb of the Sun which can highly disrupt the magnetic field topology in the corona, is a difficult task to deal with since complete knowledge of the conditions on the solar far side is not currently available. Solar Orbiter Polarimetric and Helioseismic Imager (PHI) data can help mitigate this effect, however, unless we get a 4pi view of the Sun we will be unable to completely address it.
format Preprint
id arxiv_https___arxiv_org_abs_2509_20575
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Why do solar wind models get it wrong: understanding the capabilities of time-dependent solar wind simulations
Samara, Evangelia
Provornikova, Elena
Arge, C. Nick
McCubbin, Andrew
Merkin, Viacheslav G.
Solar and Stellar Astrophysics
We explore the capabilities of time-dependent (TD) magnetohydrodynamics (MHD) solar wind simulations with the coupled WSA model of the solar corona and GAMERA model of the inner heliosphere. We compare TD with steady state (SS) simulations and with in situ data from multiple spacecraft (Earth, STEREO-A, PSP). We show that TD predictions, although better than SS predictions, substantially mispredict the solar wind at different heliospheric locations. We identified three reasons for that: (1) the uncalibrated WSA velocity formula used to generate solar wind velocities at the inner boundary of a heliospheric domain, (2) the extraction of the WSA boundary conditions for input into MHD models very high in the corona, and (3) the abrupt and partial emergence of active regions from the solar east limb. Evaluation of one year of TD predictions at Earth and STEREO-A locations shows that by tuning accordingly the WSA relationship when used with MHD models, and by extracting the WSA boundary conditions lower in the corona (at 5 Rs instead of 21.5 Rs), can lead to improved predictions. However, the abrupt emergence of active regions from the east limb of the Sun which can highly disrupt the magnetic field topology in the corona, is a difficult task to deal with since complete knowledge of the conditions on the solar far side is not currently available. Solar Orbiter Polarimetric and Helioseismic Imager (PHI) data can help mitigate this effect, however, unless we get a 4pi view of the Sun we will be unable to completely address it.
title Why do solar wind models get it wrong: understanding the capabilities of time-dependent solar wind simulations
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2509.20575