Related Experiment Video
Updated: Jun 30, 2026

08:01
Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
Magnetic fields in the solar photosphere
1School of Mathematics and Statistics, Newcastle University, Newcastle upon Tyne, UK. paul.bushby@ncl.ac.uk
Summary
Recent solar observations reveal complex photospheric magnetic fields. Models now explain sunspot structures and localized features, advancing our understanding of solar magnetism and turbulent convection.
Area of Science:
- Solar physics
- Magnetohydrodynamics
- Plasma physics
Background:
- High-resolution solar observations reveal intricate photospheric magnetic features.
- These observations enhance theoretical understanding of magnetic fields and turbulent convection.
Purpose of the Study:
- Review recent advancements in modeling photospheric magnetic fields.
- Focus on complex structures in sunspot umbrae and penumbrae.
- Discuss models for localized magnetic fields in less active regions.
Main Methods:
- Analysis of high-resolution observational data.
- Theoretical modeling of magnetic field structures.
- Comparison of models with observational data.
Main Results:
- Detailed description of complex magnetic field structures in sunspots.
- Models now explain localized magnetic features in the photosphere.
- Improved understanding of magnetic field interactions with turbulent convection.
Conclusions:
- Significant progress in modeling photospheric magnetic fields.
- Ongoing theoretical challenges presented by future observations.
- Identification of remaining unanswered questions in solar magnetism research.
Related Concept Videos
Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
Magnetic Field Lines
The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
Magnetic field lines follow several hard-and-fast rules:
Magnetic Field of a Solenoid
A solenoid is a conducting wire coated with an insulating material, wound tightly in the form of a helical coil. The magnetic field due to a solenoid is the vector sum of the magnetic fields due to its individual turns. Therefore, for an ideal solenoid, the magnetic field within the solenoid is directly proportional to the number of turns per unit length and the current. Conversely, the magnetic field outside the solenoid is zero.
Consider a solenoid with 100 turns wrapped around a cylinder of...
Consider a solenoid with 100 turns wrapped around a cylinder of...
Magnetic Flux
The magnetic flux measures the number of magnetic field lines passing through a given surface area. The SI unit for magnetic flux is the weber (Wb). Magnetic flux is a scalar quantity. It depends on three factors: the strength of the magnetic field B, the area through which the field lines pass, and the relative orientation of the field with the surface area.
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...
Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Magnetic Field Of A Current Loop
Consider a circular loop with a radius a, that carries a current I. The magnetic field due to the current at an arbitrary point P along the axis of the loop can be calculated using the Biot-Savart law.
