Solens dynamiske rotation: The dynamic rotation of the sun

Abstract

The article analyses the interior rotation of the sun, inferred from observations of 'sunquakes' with the GONG network of telescopes and instruments on the SOHO satellite. The sun is a sphere of gas and can therefore rotate at different rates in different regions. At the surface the rotation period varies from around 25 days at the equator to more than 30 days near the poles. This variation is largely maintained in the outer around 27 per cent of the solar radius. The inner regions rotate at nearly constant rate. Between the two regions there is a thin zone, the so-called tachocline, where the rotation rate changes rapidly with position. This zone is thought to play an important role in the creation of the solar magnetic field and its 11-year variation, reflected in the variation in the number of sunspots. The very detailed determinations of solar rotation has shown regions with small variations in time of the rotation rate, closely related to the concentration at specific latitudes of the presence of sunspots.