Ground-based and SOHO observations of polar plumes during eclipse Original Research Article

Polar plumes are observed in polar regions during the minimum activity phase. Their existence, stability, and curved structure remain unsolved problems. Characteristics of polar plumes observed at the 4 solar eclipses of 1994, 1995, 1997, and 1998 are described. Temperature of polar plumes, derived from the density scale height, is about 106 K.