North-South asymmetry of the daily interplanetary magnetic field spiral during the period: 1965–1990
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We have extended our earlier study of the dependance of interplanetary magnetic field (IMF) spiral on the magnetic polarity to cover the 26-year period 1965–1990. Our analysis reveals that: 1. The spiral angle north of the current sheet is higher than south of it. 2. During both of negative solar polarity epochs the IMF spiral is stable; it shows more variation during positive polarity epoch. 3. The included angle is lower than 180° during negative polarity epochs and higher than 180° during positive polarity epoch. 4. The Earth spent more time north of the current sheet during our period of analysis.
KeywordsMagnetic Field Current Sheet Interplanetary Magnetic Field Negative Polarity Magnetic Polarity
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