Electrical conductivity gradients in sunspots

✍ Scribed by Martin D. Altschuler

• Publisher: Springer
• Year: 1967
• Tongue: English
• Weight: 662 KB
• Volume: 1
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00151363

✦ Synopsis

Recently E. H. Schroeter showed that the electrical conductivity of the sunspot umbra, at least in the upper photospheric layers, is about ten-thousand times less than the value used by Cowling. This result implies that electrical conductivity gradients near sunspots may be relatively large. Upon taking such gradients into consideration, we find that the photosphere is current free and that current rings might encircle the sunspot, under suitable conditions, both in the lower photosphere and in the chromosphere. Plasma motions are neglected in the calculation.