Predicting the Amplitude and Hemispheric Asymmetry of Solar Cycle 25 with Surface Flux Transport

Abstract

Evidence strongly indicates that the strength of the Sun's polar fields near the time of a sunspot cycle minimum determines the strength of the following solar activity cycle. We use our Advective Flux Transport (AFT) code, with flows well constrained by observations, to simulate the evolution of the Sun's polar magnetic fields from early 2016 to the end of 2019 --- near the expected time of Cycle 24/25 minimum. We run a series of simulations in which the uncertain conditions (convective motion details, active region tilt, and meridional flow profile) are varied within expected ranges. We find that the average strength of the polar fields near the end of Cycle 24 will be similar to that measured near the end of Cycle 23, indicating that Cycle 25 will be similar in strength to the current cycle. In all cases the polar fields are asymmetric with fields in the south stronger than those in the north. This asymmetry would be more pronounced if not for the predicted weakening of the southern polar fields in late 2016 and through 2017. After just four years of simulation the variability across our ensemble indicates an accumulated uncertainty of about 15\%. This accumulated uncertainty arises from stochastic variations in the convective motion details, the active region tilt, and changes in the meridional flow profile. These variations limit the ultimate predictability of the solar cycle.

8 pages 7 figures Accepted for publication in Journal of Geophysical Research - Space Physics

References in corpus (4)

• Predicting solar cycle 24 with a solar dynamo model
• Solar activity forecast with a dynamo model
• Effects of Meridional Flow Variations on Solar Cycles 23 and 24
• Measurements of the Sun's High Latitude Meridional Circulation

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• Improvement of solar cycle prediction: Plateau of solar axial dipole moment
• Physical Models for Solar Cycle Predictions
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• Comparison of physics-based prediction models of solar cycle 25
• Dynamo Model for North-South Asymmetry of Solar Activity
• Predicting the Timing of the the Solar Cycle 25 Polar Field Reversal
• North-South Asymmetry in Solar Activity and Solar Cycle Prediction, V: Prediction for the North-South Asymmetry in the Amplitude of Solar Cycle 25
• Investigation of the Middle Corona with SWAP and a Data-Driven Non-Potential Coronal Magnetic Field Model
• Zonal harmonics of solar magnetic field for solar cycle forecast
• Hemispheric analysis of the magnetic flux in regular and irregular solar active regions
• Prediction of the Solar Polar Fields in 2026: An Unusually Weak Level Across the Last Five Solar Cycles
• Effect of Nonlinear Surface Inflows into Activity Belts on Solar Cycle Modulation
• Solar Cycle Prediction: Challenges, Progress, and Future Perspectives
• Active-region Modulation of Subsurface Meridional Flows and Magnetic Flux Transport on the Sun