Since last October the sun has developed one of the highest secondary peaks ever measured, if not the highest. The secondary peak will probably go up again next month. No solar physicist saw it coming. Are sunspots fading away, or coming back? At this point, nobody knows for sure what is going on or how it will affect climate change.
Another new solar sunspot record peak of 73.2 was set for Cycle 24 last month. It smashed the old 68.9 record peak set the previous month. In a big surprise, it’s over six spots higher than the first sunspot peak set in early 2012 and will probably go up. A secondary peak that much above the first is almost unheard of.
The new sunspot peak is unusual for two conflicting reasons:
- The secondary peak is higher than the first
- Current physics suggests the solar cycle should be weakening
Conflicting signals coming from the sun muddles how it might affect earth’s future climate. A more active sun will have a warming effect. A less active sun, predicted by most solar physicists, will have a cooling effect.
The sun hasn’t decided what it wants to do yet.
The Royal Observatory of Belgium’s Solar Information Data Center (SIDC) released the official sunspot number for March on April 1st. March averaged 92.2 spots/day. It’s down over 10 spots/day from 102.8 in February.
The reason Cycle 24 set another record high peak is because the official peak is a calculated 13-month average and sunspot activity has been higher for the last six months. 13-month averaging smoothes out wildly fluctuating monthly numbers.
Sunspot activity linked to earth climate
A new research paper published last month in India’s International Journal of Scientific Research (IJSR) found an inverse relationship between solar sunspot activity and cosmic ray intensity. The fewer sunspots there are, the more cosmic rays reach earth’s surface.
Yearly average count rate of cosmic ray intensity is well correlated with yearly mean of sunspot numbers, solar flare index and coronal index
– IJSR, P.L. Verma et al., March 2014
This is an important result because cosmic rays are suspected triggers of cloud formation. The more cosmic rays there are the more clouds are formed. More cloud cover has a cooling effect on earth.
The CLOUD experiment at CERN is searching for a suspected connection between ionizing radiation (cosmic rays) and cloud formation. Though the suspected link has not yet been found, promising early results connect sulfuric acid aerosols to cloud formation.
CERN, which straddles the Swiss-French border, is the world’s largest particle accelerator where the famous Higgs-Boson particle was discovered.
During the 11-year sunspot cycle solar variability doesn’t stay long enough in one condition to have a measurable effect on earth’s climate. The IPCC doesn’t account for it in climate modeling.
The sunspot cycle is a highly variable feature of the sun. Sometimes it gets weak or disappears entirely; as happened during a 75-year period called the Maunder Minimum when it got so cold it was named the Little Ice Age.
Prolonged inactivity reduces the solar wind allowing ionizing radiations, like cosmic rays, penetration to the earth’s surface. That or related processes will potentially cool the planet.
Is the next Maunder Minimum at hand?
Three key pieces of evidence from a 2011 solar physics meeting suggest the sun is slipping into another prolonged period of solar inactivity:
- The solar jet stream for Cycle 25 is delayed
- Solar magnetic field strength is weakening
- Weakening of the poleward surge in coronal magnetism
Put all together, these three diverse results convinced most solar physicists in 2011 that Cycle 25 may be the weakest since the Maunder Minimum of the 1600s.
The current solar cycle, Cycle 24, is already the weakest in 100 years even with the resurgence of sunspot activity over the last six months.