Related Experiment Video
Updated: Jul 12, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
A model of solar luminosity modulation by magnetic activity between 1954 and 1984
Abstract:
A simple model based on the changes in excess radiation from bright magnetic faculae and on changes in reduced radiation from dark spots is remarkably successful in matching the slow variations of total solar irradiance measured simultaneously by the ERB and ACRIM satellite radiometers between 1981 and 1984. This model was extended back to 1954 to reconstruct the modulation of irradiance by magnetic activity during the past three 11-year solar cycles. The model predicts that the sun is consistently brighter at activity maximum than at minimum. The 0.07 percent brightening at the peak of the last cycle in 1980 was more pronounced than the brightenings found for either of the two previous cycles, even though cycle 19, which peaked around 1957, had the largest sunspot number amplitude in the history of reliable sunspot records.
Related Concept Videos
Magnetic Flux
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...
Magnetostatic Boundary Conditions
Magnetic Field of a Solenoid
Consider a solenoid with 100 turns wrapped around a cylinder of...
Magnetic Field Lines
Magnetic field lines follow several hard-and-fast rules:
Magnetic Damping
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
Energy In A Magnetic Field
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus negligible.
The energy...

