The structure of a sunspot

✍ Scribed by P. R. Wilson

• Publisher: Springer
• Year: 1968
• Tongue: English
• Weight: 865 KB
• Volume: 3
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00155160

✦ Synopsis

A new model for the structure of a sunspot is put forward. The features of the model are (i) the deep inhibition of convection by magnetic fields, (ii) the formation of a 'cool cone' above the region of inhibition of convective transfer by the energy diverted around tiffs region, and (iii) the development of the penumbra by the interaction of strong magnetic field with thermal forces in a region where the opacity prevents the transport of energy by radiation atone. A clear distinction is made between a pore, which results from the inhibition of deep convection across an area considerably greater than that of the pore, and isolated penumbral filaments, which result from strong local fields in the surface regions.

It is shown that this new model provides a simple account of the birth and development of a sunspot, and this is contrasted with the difficulties faced by alternative models. * On leave from the University of Sydney.