is proposed which represents an improvement over the earlier Wroclaw-Ondrejov sunspot
model. The main component is assumed to consist of cold matter at photospheric levels, a
thin chromosphere, a shallow transition region, and a deep-set corona. The secondary
component in the model has a volume filling factor of 5-10 percent at all heights and is
suggested to consist of thin fine-structure elements which are elongated parallel to the …