强短波衰落事件的太阳活动区磁场位形先兆

本文利用北京天文台提供的高空间分辨率的活动区纵场磁图对1988年的18个活动区进行分析研究,以寻求强SWF耀斑的先兆.结果表明,一磁流在异极性磁流区浮现,同极性磁流合并、异极性磁流侵入和纵向磁场强度剧增4种磁位形演化与强SWF耀斑有密切关系。文中还用1988年9—10月份的25个活动区的磁图和耀斑资料佐证上面的结果。 

THE EVOLUTIONARY FEATURES OF THE MAGNETICCONFIGURATION IN THE ACTIVE REGIONS ANDTHE SHORT-TERM PREDICTION OF THESTRONG SWF

The magnetograms of the longitudinal field in 18 actively regions for April-December, 1988 are analysed in the paper (Huairou Station, Beijing Observatory provieded the magneto-grams). Some magnetic precursors of SWFflares (The flare causing strong Short Wave Fade-out is called as SWF flare) are distingushed from the magnetograms of the longitudinal field. They are:1. Emergence of the magnetic flux. Amagnetic flux emerges in a magnetic area with the opposite polarity (B_l≥320G). The intensity of emerging magnetic flux is larger or equal to 160G.2. Incorporation of the magnetic fluxes with similar polarity. Among the magnetic fluxes of the similar polarity participating in the incorporation, the strongest magnetic intensity is equal to or larger than 320G, tthe weakest is equal to or larger than 80G. The maximum magnetic gradient near the incorporating area after the incorporation is equal to or larger than 0.15G/km.3. Invasion of a magnetic flux with opposite polarity. Amagnetic flux (B_l≥320G) invades into an area of the magnetic flux with opposite polarity (B_l≥320G) and is continuouisly encircled by the magnetic flux with opposite polarity to 70% of all or more.4. Asharp increase in the magnetic intensity. The growth rate of magnetic intensity in an area of the magnetic flux is 960 G/day or more.There is a close relation between the SWF flares and the magnetic precursors.