191. Explaining why all solar cycles rise differently but decay in the same way
Magnetic flux loss from the solar interior due to flux emergence explains why all solar cycles decline in the same way.
Tag Archives: dynamo
178. Prediction based on the polar field rise rate suggests that Solar Cycle 25 will be slightly stronger than Cycle 24
A new model, which explores the polar field build-up rate and the amplitude of the following cycle, predicts a slightly stronger Cycle 25 than previously thought.
169. The QBO-type signals in the Subsurface flow fields during solar cycles 23 and 24
Quasi-biennial oscillations are found in the Sun’s interior rotation-rate residuals. They appear differently at different depths and latitudes, and evolve with time.
168. Introducing the SPEAR Catalogue from HMI Data
In order to make the properties of magnetic features observed by SDO/HMI more accessible, the Solar Photospheric Ephemeral and Active Region (SPEAR) catalogue has been created as an easy-to-read tabulated text file. Tilt angles from the SPEAR catalogue are shown as a histogram (top) and as a function of latitude (bottom) with colors indicating all regions (blue), regions with anti-Joy (red), and anti-Hale (purple) tilts. Over 40% of regions disobey the laws of Joy and Hale.
159. Magnetic Field Dependence of Bipolar Magnetic Region Tilts on the Sun: Indication of Tilt Quenching
Magnetic-field dependence of active regions’ tilt angles are analyzed using the MDI and HMI observations for two solar cycles. The variation of the tilt angles with the maximum magnetic-field strength of the ARs indicates a nonlinear tilt quenching in the Babcock–Leighton process.
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.
128. Evolution of Magnetic Helicity in Solar Cycle 24
A novel approach is developed to reconstruct the surface magnetic helicity density for the Sun or sun-like stars. The method is applied on the SDO/HMI-observed vector field synoptic data to study the temporal evolution of the Sun’s magnetic helicity density during Solar Cycle 24.
118. Detection of Dynamo Waves inside the Sun
An analysis of zonal flow acceleration/deceleration inside the Sun reveals patterns of dynamo waves, and suggests that the primary seat of the dynamo is located in a high-latitude zone of the tachocline.
112. A possible explanation of the double peaks in solar cycles
Through simulations using Babcock-Leighton flux transport model, it is found that the abrupt changes on the polar field near solar minimum could be the cause of the sunspot number double peaks in the next solar cycle.
109. How Many Active Regions Are Necessary to Predict the Solar Dipole Moment?
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.