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D. A. Falconer (UAH/MSFC/NSSTC), R. L. Moore, G. A. Gary (NASA/MSFC/NSSTC), S. Balasubramanian (UAH/ NSSTC)
We report further results from our ongoing assessment of magnetogram-based measures of active-region nonpotentiality (magnetic shear and twist), magnetic complexity and size as predictors of coronal mass ejections (CMEs). From a set of 36 vector magnetograms of predominantly bipolar active regions (Falconer, Moore, & Gary 2004, ApJ, submitted), we have found: (1) Each of five different measures of active-region nonpotentiality has a 75-80 (with correlation confidence level > 95%) in predicting whether an active region will produce a CME within 2 days after the magnetogram. (2) One of these measures can be obtained from a line-of-sight magnetogram without use of a vector magnetogram. Hence this measure appears to be the best practical measure of active-region nonpotentiality for operational CME forecasting. (3) Our measure of active-region size has a 65% success rate in predicting CMEs in this window, but the correlation is not statistically significant (confidence level ~ 80%) for our sample size. We have applied a measure of active-region complexity (the fraction of magnetic flux not in the active region’s primary bipole) to our set of 36 magnetograms and found a correlation with the CME productivity of the active regions. We are also applying measures of nonpotentiality, size, and complexity to multi-bipolar active regions to assess their CME-prediction ability for these more complicated active regions.
This work was funded by NASA through its LWS TR&T Program and its Solar and Heliospheric Physics SR&T Program, and by NSF through its Solar Terrestrial Research and SHINE Programs.
The author(s) of this abstract have provided an email address for comments about the abstract: david.falconer@msfc .nasa.gov
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Bulletin of the American Astronomical Society, 36 #2
© YEAR. The American Astronomical Soceity.