Solar filaments are known to exhibit a hemispheric pattern in their chirality where
dextral/sinistral filaments dominate in the northern/southern hemisphere. This
pattern which has only been quantified in detail for the rising phase of the solar
cycle, illustrates a global pattern of magnetic helicity and free magnetic energy
that is critical for filament eruptions and CMEs. We show that this pattern can be
explained through data driven 3D global magnetic field simulations of the Sun's
large-scale magnetic field (Yeates at al 2008). Through a detailed comparison with
109 filaments over a 6 month period, the model correctly reproduces the filament
chirality and helicity with a 96% agreement for 109 filaments. Following the models
success, the data driven simulation is extended to run over a full solar cycle
(Yeates and Mackay 2012) where predictions are made for the spatial and temporal
dependence of the hemispheric pattern in the declining phase of the solar cycle.
This prediction may be tested through new observing programs designed for
the declining phase of the present cycle.


Yeates, Mackay and van Ballegooijen, A, 2008, Solar Physics, 247, 103
Yeates and Mackay, 2012, ApJ, 753, L34