ORCID Profile
0000-0001-8975-7605
Current Organisations
University of California, Berkeley
,
University of Colorado at Boulder
,
Montana State University Bozeman
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Publisher: American Astronomical Society
Date: 10-2020
Abstract: The Coronal Global Evolutionary Model (CGEM) provides data-driven simulations of the magnetic field in the solar corona to better understand the build-up of magnetic energy that leads to eruptive events. The CGEM project has developed six capabilities. CGEM modules (1) prepare time series of full-disk vector magnetic field observations to (2) derive the changing electric field in the solar photosphere over active-region scales. This local electric field is (3) incorporated into a surface flux transport model that reconstructs a global electric field that evolves magnetic flux in a consistent way. These electric fields drive a (4) 3D spherical magnetofrictional (SMF) model, either at high resolution over a restricted range of solid angles or at lower resolution over a global domain to determine the magnetic field and current density in the low corona. An SMF-generated initial field above an active region and the evolving electric field at the photosphere are used to drive (5) detailed magnetohydrodynamic (MHD) simulations of active regions in the low corona. SMF or MHD solutions are then used to compute emissivity proxies that can be compared with coronal observations. Finally, a lower-resolution SMF magnetic field is used to initialize (6) a global MHD model that is driven by an SMF electric field time series to simulate the outer corona and heliosphere, ultimately connecting Sun to Earth. As a demonstration, this report features results of CGEM applied to observations of the evolution of NOAA Active Region 11158 in 2011 February.
Publisher: American Astronomical Society
Date: 24-07-2023
Abstract: We present the first results of the hybrid data-driven magnetofrictional (MF) and data-constrained magnetohydrodynamic (MHD) simulations of solar active region NOAA 11158, which produced an X-class flare and coronal mass ejection on 2011 February 15. First, we apply the MF approach to build the coronal magnetic configuration corresponding to the SDO/HMI photospheric magnetograms by using the JSOC PDFI_SS electric field inversions at the bottom boundary of the simulation domain. We then use the preeruptive MF state at about 1.5 hr before the observed X-class flare as the initial state for the MHD simulation, assuming a stratified polytropic solar corona. The MHD run shows that the initial magnetic configuration containing twisted magnetic fluxes and a three-dimensional (3D) magnetic null point is out of equilibrium. We find the eruption of a complex magnetic structure consisting of two magnetic flux ropes, as well as the development of flare ribbons, with their morphology being in good agreement with observations. We conclude that the combination of the data-driven MF and data-constrained MHD simulations is a useful practical tool for understanding the 3D magnetic structures of real solar ARs that are unobservable otherwise.
Publisher: American Astronomical Society
Date: 22-01-2019
Publisher: American Geophysical Union (AGU)
Date: 06-2015
DOI: 10.1002/2015SW001191
Publisher: American Astronomical Society
Date: 31-07-2023
Publisher: American Astronomical Society
Date: 31-07-2023
Publisher: American Astronomical Society
Date: 24-04-2020
Publisher: American Astronomical Society
Date: 31-07-2023
Publisher: American Astronomical Society
Date: 31-07-2023
Location: United States of America
No related grants have been discovered for Maria Kazachenko.