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The Sun’s Open–Closed Flux Boundary and the Origin of the Slow Solar Wind (2025)
Journal Article
Wilkins, C. P., Pontin, D. I., Yeates, A. R., Antiochos, S. K., Schunker, H., & Lamichhane, B. (2025). The Sun’s Open–Closed Flux Boundary and the Origin of the Slow Solar Wind. The Astrophysical Journal, 985(2), Article 190. https://doi.org/10.3847/1538-4357/adcd65

The Sun’s open–closed flux boundary (OCB) separates closed and open magnetic field lines, and is the site for interchange magnetic reconnection processes thought to be linked to the origin of the slow solar wind (SSW). We analyze the global magnetic... Read More about The Sun’s Open–Closed Flux Boundary and the Origin of the Slow Solar Wind.

Winding and magnetic helicity in periodic domains (2025)
Journal Article
Xiao, D., Prior, C. B., & Yeates, A. R. (2025). Winding and magnetic helicity in periodic domains. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 481(2307), Article 20240152. https://doi.org/10.1098/rspa.2024.0152

In simply-connected Euclidean domains, it is well-known that the topological complexity of a given magnetic field can be quantified by its magnetic helicity, which is equivalent to the total, flux-weighted winding number of magnetic field lines. Ofte... Read More about Winding and magnetic helicity in periodic domains.

Persistence and Burn-in in Solar Coronal Magnetic Field Simulations (2025)
Journal Article
Hall, E. J., Meyer, K. A., & Yeates, A. R. (2025). Persistence and Burn-in in Solar Coronal Magnetic Field Simulations. The Astrophysical Journal, 979(1), Article 88. https://doi.org/10.3847/1538-4357/ad99db

Simulations of solar phenomena play a vital role in space-weather prediction. A critical computational question for automating research workflows in the context of data-driven solar coronal magnetic field simulations is quantifying a simulation's bur... Read More about Persistence and Burn-in in Solar Coronal Magnetic Field Simulations.

Latitude Quenching Nonlinearity in the Solar Dynamo (2025)
Journal Article
Yeates, A. R., Bertello, L., Pevtsov, A. A., & Pevtsov, A. A. (2025). Latitude Quenching Nonlinearity in the Solar Dynamo. The Astrophysical Journal, 978(2), Article 147. https://doi.org/10.3847/1538-4357/ad99d0

We compare two candidate nonlinearities for regulating the solar cycle within the Babcock–Leighton paradigm: tilt quenching (whereby the tilt of active regions is reduced in stronger cycles) and latitude quenching (whereby flux emerges at higher lati... Read More about Latitude Quenching Nonlinearity in the Solar Dynamo.

A New Field Line Tracer for the Study of Coronal Magnetic Topologies (2024)
Journal Article
Aslanyan, V., Scott, R. B., Wilkins, C. P., Meyer, K. A., Pontin, D. I., & Yeates, A. R. (2024). A New Field Line Tracer for the Study of Coronal Magnetic Topologies. The Astrophysical Journal, 971(2), Article 137. https://doi.org/10.3847/1538-4357/ad55ca

We present a new code for the tracing of magnetic field lines and calculation of related quantities such as the squashing factor in the solar corona. The Universal Fieldline Tracer (UFiT) is an open-source package that can currently take inputs direc... Read More about A New Field Line Tracer for the Study of Coronal Magnetic Topologies.

The Sun’s Non-Potential Corona over Solar Cycle 24 (2024)
Journal Article
Yeates, A. R. (2024). The Sun’s Non-Potential Corona over Solar Cycle 24. Solar Physics, 299(6), Article 83. https://doi.org/10.1007/s11207-024-02328-5

The global magnetic field in the solar corona is known to contain free magnetic energy and magnetic helicity above that of a current-free (potential) state. But the strength of this non-potentiality and its evolution over the solar cycle remain uncer... Read More about The Sun’s Non-Potential Corona over Solar Cycle 24.

Transition to a weaker Sun: Changes in the solar atmosphere during the decay of the Modern Maximum (2024)
Journal Article
Mursula, K., Pevtsov, A. A., Asikainen, T., Tähtinen, I., & Yeates, A. R. (2024). Transition to a weaker Sun: Changes in the solar atmosphere during the decay of the Modern Maximum. Astronomy & Astrophysics, 685, Article A170. https://doi.org/10.1051/0004-6361/202449231

Context. The Sun experienced a period of unprecedented activity during the 20th century, now called the Modern Maximum (MM). The decay of the MM after its maximum in cycle 19 has changed the Sun, the heliosphere, and the planetary environments in man... Read More about Transition to a weaker Sun: Changes in the solar atmosphere during the decay of the Modern Maximum.

A Near-half-century Simulation of the Solar Corona (2024)
Journal Article
Aslanyan, V., Meyer, K. A., Scott, R. B., & Yeates, A. R. (2024). A Near-half-century Simulation of the Solar Corona. Astrophysical Journal Letters, 961(1), Article L3. https://doi.org/10.3847/2041-8213/ad1934

We present an overview of results from a magnetofrictional model of the entire solar corona over a period of 47 yr. The simulation self-consistently reproduces decades of solar phenomena, varying in duration between rapid eruptions and the long-term... Read More about A Near-half-century Simulation of the Solar Corona.

Computation of Winding-Based Magnetic Helicity and Magnetic Winding Density for SHARP Magnetograms in Spherical Coordinates (2023)
Journal Article
Xiao, D., Prior, C. B., & Yeates, A. R. (2023). Computation of Winding-Based Magnetic Helicity and Magnetic Winding Density for SHARP Magnetograms in Spherical Coordinates. Solar Physics, 298(10), Article 116. https://doi.org/10.1007/s11207-023-02211-9

Magnetic helicity has been used widely in the analysis and modelling of solar active regions. However, it is difficult to evaluate and interpret helicity in spherical geometry since coronal magnetic fields are rooted in the photosphere and helicity i... Read More about Computation of Winding-Based Magnetic Helicity and Magnetic Winding Density for SHARP Magnetograms in Spherical Coordinates.

Eruptivity Criteria for Solar Coronal Flux Ropes in Magnetohydrodynamic and Magnetofrictional Models (2023)
Journal Article
Rice, O. E. K., & Yeates, A. R. (2023). Eruptivity Criteria for Solar Coronal Flux Ropes in Magnetohydrodynamic and Magnetofrictional Models. Astrophysical Journal, 955(2), Article 114. https://doi.org/10.3847/1538-4357/acefc1

We investigate which scalar quantity or quantities can best predict the loss of equilibrium and subsequent eruption of magnetic flux ropes in the solar corona. Our models are initialized with a potential magnetic arcade, which is then evolved by mean... Read More about Eruptivity Criteria for Solar Coronal Flux Ropes in Magnetohydrodynamic and Magnetofrictional Models.

Surface Flux Transport on the Sun (2023)
Journal Article
Yeates, A., Cheung, M., Jiang, J., Petrovay, K., & Wang, Y.-M. (online). Surface Flux Transport on the Sun. Space Science Reviews, 219, Article 31. https://doi.org/10.1007/s11214-023-00978-8

We review the surface flux transport model for the evolution of magnetic flux patterns on the Sun’s surface. Our underlying motivation is to understand the model’s prediction of the polar field (or axial dipole) strength at the end of the solar cycle... Read More about Surface Flux Transport on the Sun.

Spherical winding and helicity (2023)
Journal Article
Xiao, D., Prior, C., & Yeates, A. (2023). Spherical winding and helicity. Journal of Physics A: Mathematical and Theoretical, 56(20), Article 205201. https://doi.org/10.1088/1751-8121/accc17

In ideal magnetohydrodynamics, magnetic helicity is a conserved dynamical quantity and a topological invariant closely related to Gauss linking numbers. However, for open magnetic fields with non-zero boundary components, the latter geometrical inter... Read More about Spherical winding and helicity.

Automated driving for global non-potential simulations of the solar corona (2022)
Journal Article
Yeates, A., & Bhowmik, P. (2022). Automated driving for global non-potential simulations of the solar corona. Astrophysical Journal, 935(1), Article 13. https://doi.org/10.3847/1538-4357/ac7de4

We describe a new automated technique for active region emergence in coronal magnetic field models, based on the inversion of the electric field locally from a single line-of-sight magnetogram for each region. The technique preserves the arbitrary sh... Read More about Automated driving for global non-potential simulations of the solar corona.

Eruptivity Criteria for Two-dimensional Magnetic Flux Ropes in the Solar Corona (2022)
Journal Article
Rice, O. E., & Yeates, A. R. (2022). Eruptivity Criteria for Two-dimensional Magnetic Flux Ropes in the Solar Corona. Frontiers in Astronomy and Space Sciences, 9, Article 849135. https://doi.org/10.3389/fspas.2022.849135

We apply the magneto-frictional approach to investigate which quantity or quantities can best predict the loss of equilibrium of a translationally-invariant magnetic flux rope. The flux rope is produced self-consistently by flux cancellation combined... Read More about Eruptivity Criteria for Two-dimensional Magnetic Flux Ropes in the Solar Corona.

Exploring the Origin of Stealth Coronal Mass Ejections with Magnetofrictional Simulations (2022)
Journal Article
Bhowmik, P., Yeates, A., & Rice, O. (2022). Exploring the Origin of Stealth Coronal Mass Ejections with Magnetofrictional Simulations. Solar Physics, 297(3), Article 41. https://doi.org/10.1007/s11207-022-01974-x

Coronal mass ejections (CMEs) – among the most energetic events originating from the Sun – can cause significant and sudden disruption to the magnetic and particulate environment of the heliosphere. Thus, in the current era of space-based technologie... Read More about Exploring the Origin of Stealth Coronal Mass Ejections with Magnetofrictional Simulations.

On the limitations of magneto-frictional relaxation (2022)
Journal Article
Yeates, A. (2022). On the limitations of magneto-frictional relaxation. Geophysical and Astrophysical Fluid Dynamics, 116(4), 305-320. https://doi.org/10.1080/03091929.2021.2021197

The magneto-frictional method is used in solar physics to compute both static and quasi-static models of the Sun’s coronal magnetic field. Here, we examine how accurately magneto-friction (without fluid pressure) is able to predict the relaxed state... Read More about On the limitations of magneto-frictional relaxation.

Global Coronal Equilibria with Solar Wind Outflow (2021)
Journal Article
Rice, O. E., & Yeates, A. R. (2021). Global Coronal Equilibria with Solar Wind Outflow. Astrophysical Journal, 923(1), Article 57. https://doi.org/10.3847/1538-4357/ac2c71

Given a known radial magnetic field distribution on the Sun’s photospheric surface, there exist wellestablished methods for computing a potential magnetic field in the corona above. Such potential fields are routinely used as input to solar wind mode... Read More about Global Coronal Equilibria with Solar Wind Outflow.

A Comparison of Sparse and Non-sparse Techniques for Electric-Field Inversion from Normal-Component Magnetograms (2021)
Journal Article
Mackay, D., & Yeates, A. (2021). A Comparison of Sparse and Non-sparse Techniques for Electric-Field Inversion from Normal-Component Magnetograms. Solar Physics, 296(12), Article 178. https://doi.org/10.1007/s11207-021-01924-z

An important element of 3D data-driven simulations of solar magnetic fields is the determination of the horizontal electric field at the solar photosphere. This electric field is used to drive the 3D simulations and inject energy and helicity into th... Read More about A Comparison of Sparse and Non-sparse Techniques for Electric-Field Inversion from Normal-Component Magnetograms.

Intrinsic winding of braided vector fields in tubular subdomains (2021)
Journal Article
Prior, C. B., & Yeates, A. R. (2021). Intrinsic winding of braided vector fields in tubular subdomains. Journal of Physics A: Mathematical and Theoretical, 54(46), Article 465701. https://doi.org/10.1088/1751-8121/ac2ea3

Braided vector fields on spatial subdomains which are homeomorphic to the cylinder play a crucial role in applications such as solar and plasma physics, relativistic astrophysics, fluid and vortex dynamics, elasticity, and bio-elasticity. Often the v... Read More about Intrinsic winding of braided vector fields in tubular subdomains.