While it is not unexpected that experts predicting how active Solar Cycle (SC) 25 will be compared to SC 24, the new forecast from NASA is significantly different than the National Weather Service forecast.
A few weeks ago, I reported that the National Weather Service forecast for SC 25 activity would be slightly greater than SC 24. They added:
“The expectation that Cycle 25 will be comparable in size to Cycle 24 means that the steady decline in solar cycle amplitude, seen from cycles 21-24, has come to an end and that there is no indication that we are currently approaching a Maunder-type minimum in solar activity.”
NASA’s prediction is different, really different. Their expert says:
Research now underway may have found a reliable new method to predict this solar activity. The Sun’s activity rises and falls in an 11-year cycle. The forecast for the next solar cycle says it will be the weakest of the last 200 years. 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. The results show that the next cycle will start in 2020 and reach its maximum in 2025.
The NASA prediction did not discuss the possibility of a Maunder minimum. However their prediction does not rule out a Maunder minimum in progress as it forecasts SC25 will not be the end of a steady decline in solar cycle amplitude.
Both of the predicting groups acknowledge that they are still far from a full understanding of how the Sun works. So, we will just have to wait and see.
Solar Cycle 24 is on its way to a “minimum” . That Minimum will probably be in late 2019 or early 2020. The video illustrates several issues that are newsworthy.
- Global Temperature measurements made by satellites are often consider the “gold standard”. Two organizations make and report their interpretation of these measurements. The UAH and RSS organizations have typically reported very nearly the same temperatures but separation of the values occurred with RSS now giving higher readings. A major part of the separation is based how to correct for the drag that these satellites encounter as the circle above the Earth.
- And a small point. When the narrator says that Cycle 24 Sunspots were “relatively high” he is comparing the Sunspot level now. However, it might cause some people to think that he means as opposed to other Solar Cycles–which by and large is not true.
Solar Cycle 24 continues to become less active. The June 2017 International Sunspot 30 day average number was 19.4. The maximum for Solar Cycle 24 occurred April 2014 at 116.4. The following chart illustrates how the solar cycle activity has dropped off. Solar Cycle 21 was larger than 22 which was larger than 23 which was larger than the current Solar Cycle 24.
The three charts above were posted on WUWT website titled “Trends in the Revised Sunspot Number Dataset“. From that posting comes the following analysis:
This posting combines the March global temperature anomaly and the Solar Cycle 24 stats. Below are the UAH satellite global temperature anomalies from Dr Roy Spencer’s website. The stats below the graph show the summary since 2016 through March 2017 for the regions.
YEAR MO GLOBE NHEM. SHEM. TROPICS
2016 01 +0.54 +0.69 +0.39 +0.84
2016 02 +0.83 +1.16 +0.50 +0.98
2016 03 +0.73 +0.94 +0.52 +1.08
2016 04 +0.71 +0.85 +0.58 +0.93
2016 05 +0.54 +0.64 +0.44 +0.71
2016 06 +0.33 +0.50 +0.17 +0.37
2016 07 +0.39 +0.48 +0.29 +0.47
2016 08 +0.43 +0.55 +0.31 +0.49
2016 09 +0.44 +0.49 +0.38 +0.37
2016 10 +0.40 +0.42 +0.39 +0.46
2016 11 +0.45 +0.40 +0.50 +0.37
2016 12 +0.24 +0.18 +0.30 +0.21
2017 01 +0.30 +0.26 +0.33 +0.07
2017 02 +0.35 +0.54 +0.15 +0.05
2017 03 +0.19 +0.30 +0.07 +0.03
The anomaly drop of 0.16C was a substantial change. This has been happening without a La Nina following the El Nino.
Solar Cycle 24’s to-date April International Sunspot number is 26.6 versus March’s number of 17.7. So, this month is a little more active but still things are quiet. Cycle 24 began in January 2008. The mean Cycle length is 11.1 years so it should be over around January of 2019.
As noted in previous postings the solar polar field strength following a maximum is currently a popular way to predict the following Cycle strength. The Black line in the chart below is the line to watch. That line is the combined North and South solar polar field strength. So far it is slightly smaller than the size of Solar Cycle 23—thus using this theory,
it Cycle 25 should be about the same size as 24 or maybe just a bit smaller. Amended for clarity on 4/20 cbdakota
There were no visible Sunspots on 11 March 2017. There was but one Sunspot cluster showing on 12 March. This will become more common as Solar Cycle continues on its way to its demise and the beginning of Cycle 25. From Wiki, we get the record of The “Spotless days at the end of the cycle”. These numbers have been recorded since Cycle 9 that ended in March 1855. The recent “grand maximum” beginning with Cycle 18 thru Cycle 22 provides us with these numbers:
||Sunspotless days-end of cycle
|| 81.9 (Apr14)
Cycle 24 has been much less active than its recent predecessors. It was ushered in following 817 spotless days. This appears to be significant but we probably need to see how this plays out at the end of Cycle 24 and its effect on Cycle 25.
The current, seemingly, most used way to predict the size of Cycle 25 is examining the Solar Polar Field Strength of Cycle 24. As noted in previous postings the technique is to examine the average field strength after the Maximum occurs. Typically, it levels out. The average field strength is computed by adding North and South field strengths and dividing by 2. Below is a plot of the field strength for Cycles 21,22,23 and 24. Looking at the left
plot, so far the Cycle 24 average is about 50. The high point for Cycle 23 looks to have been about 70. This suggests that Cycle25 will be smaller than 24. But Cycle 24 average field strength of nominally about 50, could become larger over the next year. So again, we will have to wait and see.
(Unfortunately, the expanded left chart is unavailable.An expanded left chart was put in this posting but it was too large to show the period of the Cycle 23 and 24.)
Below is the February 2017 Cycle 24 chart comparing it to Cycle 23.
German solar scientists, Frank Bosse and Fritz Vahrenholt say that Solar Cycle 24 is the “..third weakest cycle since observations began in 1755.” The Accumulated Sunspot Anomaly until 97 months after cycle start is shown on the figure below:
Figure 2: Comparison of all the solar cycles. The chart shows the accumulated sunspot number anomaly from the mean value.
The mean value is noted at zero and Cycle 24 is running 3817 spots less than the mean and only two other Cycle had fewer. Note that the seven Cycles that preceded Cycle 24 had more sunspots than the mean.
Before Solar Cycle 24 began, estimates of how active it would be were made by many experts. Because the Sunspot counting system has changed, the estimates have to be translated from the predictions made before the change. NASA’s top Expert using Sunspot as a proxy for activity, estimated it would be in the well over 160 (new system number ca. 265). Most of the estimates at the time were like NASAs. However, Cycle 24 has been much less active than most of the experts expected. The count using the new numbering system for Cycle 24 peak Sunspots at the Solar Maximum is 117. On the other hand, Leif Svalgaard and his partners estimated about 70 (new system ca. 117) which turns out to be as good as it gets. Estimating what Solar Cycle 25 will look like is already underway with many expecting Cycle 25 to be less active that has been the case with Cycle 24.
Because Svalgaard had forecast that Cycle 24 would be much less active and the forecast came reasonably close to the actual number count, it makes me curious about how he did it and what is he is predicting about Cycle 25 now. Well, I have already given that away in my 22 March 2016 blog titled “Dr Svalgaard makes a preliminary prediction of Cycle 25 size.” He thinks it will be close to the size of Cycle 24 and prehaps a little bit bigger. Once again he seems to be the contrarian.
So, how does he make these predictions. This blog will let you see the method he uses.