146. Prediction of Solar Cycle 25
Using the solar axial magnetic dipole moment obtained prior to the solar minimum, the author predicts that the maximum sunspot number of Solar Cycle 25 is about 128.
Tag Archives: magnetic field
145. Magnetic Helicity Budget of Solar Active Regions Prolific of Eruptive and Confined Flares
Analysis of magnetic helicity of eruptive and confined flaring events indicates that non-potential magnetic helicity is indicative to eruptive potentials of active regions.
144. Finding the critical decay index in solar prominence eruptions
Critical decay index is a measure of the rate at which background field intensity decreases with height over the flux ropes or erupting structures. The indices for 10 eruptive prominences are calculated, and their relations to the eruptions are discussed.
143. The New HMI 96-Minute Vector Magnetograms
New HMI 96-minute vector magnetograms are now available. Deep averaging reduces noise and enhances long-lived magnetic structures.
142. On the Lorentz Force and Torque of Solar Photospheric Emerging Magnetic Fields
A large sample statistical study of normalized Lorentz force and torques in emerging magnetic field shows that the photospheric magnetic field has a rather small Lorentz forces and torques, close to a force-free state.
141. Source Depth of Three-minute Umbral Oscillations
Apparent 3-min waves observed inside sunspot umbrae are modeled as excited about 1000 to 2000 km beneath sunspots’ surface.
140. Solar Flare Predictive Features Derived from Polarity Inversion Line Masks in Active Regions Using an Unsupervised Machine Learning Algorithm
An unsupervised machine-learning algorithm is used on selected features derived from the polarity inversion lines (PIL) mask and difference PIL mask. It is found these features are effective in predicting flaring occurrences.
139. Using Synoptic Magnetograms for Long-Term Solar Activity Forecast
The Sun’s poloidal and toroidal magnetic field components derived from synoptic magnetograms are assimilated into a mean-field dynamo model, and activity level for Cycle 25 is predicted based on this approach.
138. Electric Current Neutralization in Solar Active Regions and Its Relation to Eruptive Activity
Electric current neutralization, which measures the ratio of direct current and return current inside active regions (ARs), is studied for a total of 30 AR samples. It is found that flare-productive ARs are more likely to exhibit non-neutralized currents than those flare-quiet ARs.
135. Serial Flaring in an Active Region: Exploring Why Only One Flare is Eruptive
Of three consecutive flares that occurred in a same active region within 4 hours, why were two non-eruptive and one eruptive? Non-linear force-free modeling suggest that breakout reconnection during the first two flares weakened the overlying field, allowing the flux rope to erupt in the third.