Monday Seminar Talk (short) 17 November, 2003

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Monday Seminar Talk (short) 17 November, 2003. Taro Morimoto. Because :. The polar crown filaments need to be removed before the poles could acquire open field structure of the opposite polarity. Abstract. Close Relationship. The solar polarity reversal. - PowerPoint PPT Presentation

Transcript of Monday Seminar Talk (short) 17 November, 2003

  • Monday Seminar Talk (short) 17 November, 2003Taro Morimoto

  • AbstractThe solar polarity reversalThe cessation of high latitude CMEsClose Relationship- based on the observations for cycles 21 & 23.

  • IntroductionDisappearance and reformation of polar coronal holes. (Webb, Davis & McIntosh 1984; Bilenko 2002; Harvey & Recely 2002)Disappearance of polar crown filaments(PCF).(Waldmeier 1960; Makarov, Tlatov & Sivaraman 2001)

  • IntroductionUsing CME data of cycles 21 & 23, they tested how CMEs are intimately connected to the mechanism of polarity reversal.

  • PE and CMEsepochs of cessation of HL activity (north; : south)HCSHCSMax. excursions of heliospheric current sheet. (from Wilcox Obs.)North-south asymmetry in the high latitude (HL) activities.

  • CME occurence rateHL : High Latitude (60) [PCF-related = 1159 CMEs]LL : Low Latitude (40) [AR-related = 4607 CMEs]SSN: daily Sun Spot Number

  • Cycle 23013s3sNorthern HL(NHL)Disappearance of PCF

  • Cycle 23013s3sSouthern HL(SHL)Disappearance of PCF

  • Cycle 213s3sNorthSouthNorthern HL(NHL)Disappearance of PCF

  • Cycle 213s3sNorthSouthSouthern HL(SHL)Disappearance of PCF

  • SummaryThe epochs of solar polar reversal are closely related to the cessation of HL CME activities.Before the completion of the reversal, several temporary reversals take place with corresponding spikes in the HL CME rates.