The following is the solar part of the latest post at Die kalte Sonne.
By Frank Bosse and Fritz Vahrenholt
(Translated, edited by P Gosselin)
Our mother star was once again less active than normal in March. The observed solar sunspot number (SSN) was 54.9, which was about 2/3 of the mean value (82.5) for this month into the cycle. Here’s what the current solar cycle (SC) looks like so far:
Figure 1: The course of the current SC 24 since it began in December 2008, up to March 2016 (month 88) in red, the mean of the previous 23 cycles is shown in blue, and the similarLY (since month 73) behaving solar cycle number 5, which occurred from May 1789 to December 1810, shown in black.
The accumulated sunspot numbers this far into the cycle are plotted as the anomaly from the mean for each cycle. It shows that the current cycle is one of the weakest on record:
Figure 2: The accumulated sunspot numbers for each cycle, shown as the anomaly from the mean, 88 months into the respective cycle, going back to 1755.
SC 24 is the weakest since SCs 5, 6 and 7, a time known as the Dalton Minimum (1790-1830). It appears that the current cycle may very well wind up being weaker than SC 7 when it ends. Our sun is a very mediocre star of the spectral classification G2, similar to our neighbor star Alpha Centauri A. That is one of the reasons evolution had enough time to spawn intelligent life. A more active star most likely would not have allowed it due to the powerful solar winds that would “blow away” a planet’s atmosphere.
What follows is a beautiful picture from the Hubble space telescope:
Figure 3: The light blue star inside the “bubble” of dust and gases is very active. Through pressure it generates its stellar winds that shape a sphere that measures 10 light years in size. Near the surroundings of the star a planet with an atmosphere would be inconceivable. Photo source: NASA
So can single super flares (extremely powerful eruptions of a star’s surface) from the sun be excluded? A new study by a team of scientists led by Christoffer Karoff of the University of Aarhus in Denmark concludes: No – something of the sort could in fact happen! There are indications that in the year 775 a flare occurred, one that was much more powerful than anything we could expect in modern times, e.g. Carrington- Event 1859.
A massive explosion on the sun that could be 100 times more powerful is improbable, yet cannot be excluded. If such a flare hit the Earth, things indeed would get very uncomfortable because all power transmission lines would be impacted. Our modern energy and communication networks would be interrupted globally, and for a long time.
The requirement for this? A huge sunspot.
If one did occur, there first would be a warning period. But what precautionary measures could be implemented? Up to now we can only hope to be spared of such a massive solar flare of energy. In a sense the Danish study tells us just how dependent the Earth is on the sun’s power, its electromagnetic radiation, and its magnetic field.
Note: Prof. Fritz Vahrenholt is co-author of the book: “The Neglected Sun”.