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BEARALERTS: A successful flare prediction system

Zirin, Harold and Marquette, William (1991) BEARALERTS: A successful flare prediction system. Solar Physics, 131 (1). pp. 149-164. ISSN 0038-0938. doi:10.1007/bf00151751.

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We describe our BEARALERT program of predicting solar flares or rapid development of activity in certain sunspot groups. The purpose of the program is to test our understanding of the flare process by making public predictions via electronic mail. Neither the exact timing of the flare nor the possibility of emergence of new active regions can be predicted. But high-resolution observations of the magnetic configuration, Ha brightness and structure and other properties of a region enabled us to announce the onset of 15 of 23 major active regions over a two-year period, and 15 of 32 BEARALERTS were followed by this activity. We used high-resolution real-time data available at the Big Bear Solar Observatory (BBSO). The criteria for prediction are given and discussed, along with those for filament eruption. The success fo the BEARALERT is evaluated by counting the M- and X-class flares in six days following the alert and comparing these results with those of a number of other predictive schemes. We find the single regions chosen had about 30% more flares than the whole disk on random days, or several times more than individual regions chosen at random. There was a gain of 1.5 to 2.0 times in flare frequency compared to regions selected by spot size or complexity. We also find an improvement of 20–40% over large or complex regions that have had some flares already. The ratio of improvement has increased with time as we gained experience. In the 24-hr period following each alert, one or more M-class or greater flares occurred 72% of the time. We also checked the possibility of prediction by the 152-day interval which some workers have claimed, but found those results slightly worse than random and considerably inferior to the BEARALERTS. All of the particularly active regions that were missed either occurred during bad weather at BBSO or were missed because we only issued alerts for one region at a time.

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Additional Information:© 1991 Kluwer Academic Publishers. Provided by the NASA Astrophysics Data System. Received 12 February 1990; Revised 26 July 1990. We acknowledge several valuable suggestions by the referee. This research has been supported by the NSF under ATM-8816007, by NASA under NGL 05 002 034, and by the ONR under N00014-89-J-1069.
Funding AgencyGrant Number
NASANGL 05 002 034
Office of Naval Research (ONR)N00014-89-J-1069
Subject Keywords:Flare; Active Region; Solar Flare; Sunspot Group; Electronic Mail
Issue or Number:1
Record Number:CaltechAUTHORS:20200520-153957145
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Official Citation:Zirin, H., Marquette, W. BEARALERTS: A successful flare prediction system. Sol Phys 131, 149–164 (1991).
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:103370
Deposited By: Tony Diaz
Deposited On:20 May 2020 22:55
Last Modified:16 Nov 2021 18:20

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