The role of the magnetic field intensity and geometry in the type III burst generation

✍ Scribed by P. Zlobec; V. Ruždjak; B. Vršnak; M. Karlický; M. Messerotti

• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 373 KB
• Volume: 130
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00156777

✦ Synopsis

We study the association of type III bursts related to He flares in different magnetic environments in the period 1970-1981. Special attention is paid to flares which partly cover a major spot umbra (Z-flares). In particular we consider the location of the spots in the active regions and the magnetic field intensities of spots covered by a ribbon. The association rate with type lII bursts decreases to 17% when the flare is located inside the bipolar pattern of a large active region, compared with an association rate of 54% when the flare is situated outside it. The association rate increases with the magnetic field intensity of the spot covered by Ha emission; this is most clearly revealed for the flares occurring outside the bipolar pattern of active regions. Ninety-three percent of the flare-associated type III burst were accompanied by 10 cm radio bursts. For the most general case in which a flare is developing anywhere in an active region, the association with type III bursts generation increases with the increasing magnetic field intensity of the main spot of the group.