Tag Archives: sunspot maximum

Is the Sun’s strange double-peaked solar maximum finally ending?

Last week NOAA posted its monthly update of the solar cycle, showing the sunspot activity for the Sun in April. As I do every month, I am posting it here, with annotations to give it context.

May Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

For the third month in a row the Sun continued its drop in sunspots, with the total finally slipping below the 2009 prediction for this moment in the solar cycle. If this decline continues through to solar minimum, the shape of the solar maximum will essentially have been established, double-peaked with the second peak stronger than the first, something that solar scientists have never seen before.

At the moment I await word from the scientists that the Sun has completed the flip of its magnetic field polarity in the southern hemisphere. This flip has already occurred in the northern hemisphere, and when the south follows, the maximum will be officially over and we will officiallybegin the ramp down to solar minimum.

The big solar hotshots of 2013.

The big solar hotshots of 2013.

The article is a nice and visually fascinating overview of the twelve most impressive solar events during the past year. Interestingly, I think #7 is the most significant in that it involved things that didn’t happen.

As small sunspot group NOAA 1838 was falling apart, another active region NOAA 1839 appeared just in time to avoid a spotless day, which would have been the first since 14 August 2011! A spotless day during a solar cycle maximum is not uncommon, but it remains of course a rare event. This absolute low in sunspot number highlighted a period of very low solar activity, with hardly any flares (no C-flares from 7 till 17 September: 11 consecutive days) and no (minor) geomagnetic storms for a full month! Meanwhile, the magnetic field near the solar north pole (finally) completed its reversal, whereas this magnetic flip is still ongoing at the south pole. These reversals testify we’re close to the maximum of solar cycle 24. [emphasis mine]

The phrases in bold clarify where we presently stand with the solar cycle. The southern magnetic field is in the process of reversing, but has not yet completed the flip.