Guest post by David Archibald
Back on March 7, 2006, the National Science Foundation issued a press release predicting that the amplitude of Solar Cycle 24 would be “30 to 50 percent stronger” than Solar Cycle 23. Solar Cycle 23 had a smoothed maximum amplitude of 180.3. The press release described the forecast as “unprecedented”. Perhaps it was as in unprecedentedly wrong. Solar Cycle 24 had a smoothed maximum amplitude of 116.4 in April 2104, which made it 35% weaker than Solar Cycle 23.
NASA has recycled some of the language from that 2006 press release in this release on NASA researcher Irina Kitiashvili’s forecast of Solar Cycle 25 amplitude which includes this line:
The maximum of this next cycle – measured in terms of sunspot number, a standard measure of solar activity level – could be 30 to 50% lower than the most recent one.
This time it is 30 to 50% lower rather than higher which would put maximum smoothed amplitude in the range of 80 to 60. The graphics in Kitiashvili’s presentation differ from that. This graphic from slide nine has a peak amplitude of 50 with a range of 65 down to 40:
Figure 1: Solar Cycle 25 forecast in the context of 320 years of solar cycle data
But the graphic on the previous slide has a peak amplitude of 25:
Figure 2: Solar Cycle 25 amplitude forecast from slide 8
Let’s assume that the latter forecast of 25 is the author’s intent and apply it to the figure on slide 3 of 420 years of sunspot data:
Figure 3: Forecast from Figure 2 imposed on the 420 years of solar cycle data on slide 3.
In this figure the forecast from Figure 2 is scaled to fit on the graphic on slide 3 from Kitiashvili’s presentation. It shows that Solar Cycle 25 will be the smallest for some 300 years. The activity pattern predicted by Kitiashvili looks like the setup for the Maunder Minimum. A Maunder-like event was predicted by Schatten and Tobiska in their paper to the 34th meeting of the Solar Physics Division of the American Astronomical Society, June 2003:
“The surprising result of these long range predictions is a rapid decline in solar activity, starting with cycle #24. If this trend continues, we may see the Sun heading towards a “Maunder” type of solar activity minimum – an extensive period of reduced levels of solar activity.”
NASA’s press release is headed “Solar Activity Forecast for Next Decade Favorable for Exploration”. So spacecraft electronics and spacemen will have a lower chance of being fried by solar storms, the Earth’s thermosphere will shrink, satellites will have lower drag and stay in orbit longer. But what about life on Earth? In her 2011 paper Haigh showed an unequivocal relationship between solar activity and climate as recorded in North Atlantic ocean sediments:
Figure 4: Records extracted from ocean sediments in the North Atlantic
In Figure 4 solar activity is measured by Be10 (purple) and climate variation is shown by deposits of ice-rafted minerals (orange). Lower solar activity means that it will become colder and colder is drier. Prepare accordingly.
David Archibald is the author of American Gripen: The Solution to the F-35 Nightmare.