IT IS midnight on 22 September 2012 and the skies above Manhattan are filled with a flickering curtain of colourful light. Few New Yorkers have seen the aurora this far south but their fascination is short-lived. Within a few seconds, electric bulbs dim and flicker, then become unusually bright for a fleeting moment. Then all the lights in the state go out. Within 90 seconds, the entire eastern half of the US is without power.

Sonograms of the solar interior reveal a flow that is taking longer than usual to move from the poles to the equator and may be related to the current long minimum of solar activity.

We do not know why the torsional oscillation is slowly migrating. We also monitor the north-south meridional flow and the differential rotation, but neither is significantly different between the two cycles. The meridional flow is thought to play an important role in determining the timing and amplitude of the solar-activity cycle,15 but at a depth far below what we can presently sample reliably.

Thus, several mysteries remain in our quest to unravel the cause of the solar cycle. Because of our analysis technique, the flows in Figure 1 are precisely symmetric across the equator, but the sun shows significant differences between the northern and southern hemispheres that may play a role in the cycle behavior. These differences can be studied using other helioseismological methods, such as ring diagrams16 and time distance.17 In addition, we are developing methods to search for the deep meridional flow that should exist about 200,000km below the surface. These techniques will enable us to learn more about the roots of the sunspot cycle.

It seems that 2009 is sure to pass 1954 and 1933 to move into 4th place for sunspot-free days since 1900. Both of these years had about 240 sunspot-free days. Last year achieved 2nd place with 266 blank days,; as of Nov 2, 2009 we stand at 235 days. Given the number of days left in 2009, there’s still about an even money chance for 2009 to at least tie 2008.