Monthly Archives: September 2018

110. Onset of Photospheric Impacts and Helioseismic Waves in X9.3 Solar Flare of September 6, 2017

Contributed by Alexander Kosovichev. Posted on September 17, 2018

Analysis of HMI and KONUS/WIND data shows that photospheric and helioseismic flare impacts started to develop in compact regions in close vicinity of the magnetic polarity inversion line in the pre-impulsive phase before detection of hard X-ray emission.

109. How Many Active Regions Are Necessary to Predict the Solar Dipole Moment?

Contributed by Tim Whitbread. Posted on September 10, 2018

To assess the impact of active regions to the axial dipole moment, the authors isolate the contribution of individual regions for Cycles 21, 22, and 23 using a surface flux transport model, and find that although the top ~10% of contributors tend to define sudden large variations in the dipole moment, the cumulative contribution of many weaker regions cannot be ignored.