Two-dipole model of the asymmetric Sun

Two-dipole model of the asymmetric Sun

Blog Article

The large-scale photospheric magnetic field is commonly thought to be mainly dipolar during sunspot minima, when magnetic fields of opposite polarity cover the solar poles.However, recent studies show that the octupole harmonics contribute comparably to the spatial power of the photospheric field glitter foam vellen action at these times.Also, the even harmonics are non-zero, indicating that the Sun is hemispherically asymmetric with systematically stronger fields in the south during solar minima.We present here an analytical model of two eccentric axial dipoles of different strength, which is physically motivated by the dipole moments produced by decaying active regions.

With only four parameters, this model closely reproduces the observed large-scale photospheric field and all significant coefficients of its spherical harmonics expansion, including the even harmonics responsible for the chorulon hcg solar hemispheric asymmetry.This two-dipole model of the photospheric magnetic field also explains the southward shift of the heliospheric current sheet observed during recent solar minima.