Presentation Abstract

Presentation Number 521.18
Presentation Time: Thursday, Jun 14, 2012, 9:00 AM - 2:00 PM
Title The Sun Has A Short Memory: Turbulent Pumping Of Magnetic Flux Reduces Solar Cycle Memory And Precludes Long-term Predictions
Author Block Dibyendu Nandy1, B. B. Karak2
1Indian Institute of Science Education and Research, Kolkata, India, 2Indian Institute of Science, India.
Abstract Predicting the activity of the Sun is important because of its effect on space environmental conditions and climate. However, recent efforts to predict the amplitude of the solar cycle have resulted in diverging forecasts with no consensus. It is understood that the dynamical memory of the solar dynamo mechanism governs predictability and this memory is different for advection- and diffusion-dominated solar convection zones. By utilizing stochastically forced, kinematic dynamo simulations, we demonstrate that the inclusion of downward turbulent pumping of magnetic flux reduces the memory of both advection- and diffusion-dominated solar dynamos to only one cycle; stronger pumping degrades this memory further. We conclude that the dynamical memory of the solar cycle is short; reliable predictions for the maximum of solar activity can be made only at the preceding minimum which explains why early forecasts for the maximum of solar cycle 24 have widely diverged. Our analysis suggests that for more accurate predictions, sequential data assimilation would be necessary in forecasting models to account for the Sun's short memory.