AAS 200th meeting, Albuquerque, NM, June 2002
Session 20. Pre-eruptive Magnetic Structures
Oral, Monday, June 3, 2002, 10:00-11:30am, San Miguel

[Previous] | [Session 20] | [Next]

[20.05] Forecasting Coronal Mass Ejections from Vector Magnetograms

D. A. Falconer (UAH/MSFC/NSSTC), R. L. Moore, G. A. Gary (NASA/MSFC/NSSTC)

In a 17 vector magnetogram study of 12 bipolar active regions (Falconer, Moore, & Gary 2002, ApJ in press), we evaluated from each vector magnetogram four global measures of the magnetic field of the observed active region, and examined the correlation of each of these quantities with the CME productivity of the active regions. The four global magnetic quantities were 1) the total magnetic flux (\Phi), which is a measure of the size of an active region, and three measures of the global nonpotentiality of an active region: 2) the length of strong-field, strong-shear main neutral line (LSS), the net current (IN), and the magnetic twist parameter ( \alpha=\mu IN/\Phi). The CME productivity of each active region for each day of its disk passage was determined from Yohkoh/SXT coronal X-ray images together with GOES X-ray flux observations and, when available, SOHO/LASCO observations. For a centered time window of 5 days (day of the magnetogram ±2 days) for CME production, for each of the three measures of global nonpotentiality, whether the measure was above its median value was well correlated with whether the active region produced any CMEs. For each, the confidence level of the correlation was \ge 99%.

The sample size was too small to show a statistically significant correlation (confidence level \ge 95%) of the global nonpotentiality measures with future CME production, that is, from the date of the magnetogram forward. We are doubling our sample, and will report on our statistical evaluation of global nonpotentiality as a predictor of future CME productivity. The vector magnetograms of the added active regions are from the first year of operation (September 2000 - October 2001) of the upgraded MSFC vector magnetograph.

This work is funded by NSF through its Space Weather Program, and by NASA through its Living With a Star Targeted Research and Technology Program and its Solar and Heliospheric Physics Supporting Research and Technology Program. The upgrade of the MSFC vector magnetograph was funded by the HESSI mission.

The author(s) of this abstract have provided an email address for comments about the abstract: david.falconer@msfc.nasa.gov

[Previous] | [Session 20] | [Next]

Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.