In the convective zone, rising and falling currents carry heat from the radiative zone to the surface. This nonstop churning is similar to what happens when you boil water on a stove
Space Science Institute (SSI),Space Weather Center, Glossary of Space Weather-Related Terms, Colorado, USA 2011. http://www.spaceweathercenter.org/glossary/001/01. html, (Space Wthr - Amer) {860}