Project

Solar cycle minima and maxima

Updates
0 new
0
Recommendations
0 new
0
Followers
0 new
1
Reads
0 new
53

Project log

Patrick Geryl
added a research item
In our previous article we found a relationship between the adjusted solar flux and the start of sunspot cycles. We used the 13-month smoothed average for it. Building further on this we found a surprising proof that sunspots and the adjusted solar flux are even more related. If we replace the standard smoothing formula with a 365 days smoothed average, some at first sight unbelievable coincidences turn up in the cycle 24-25 transition. The lows from NOAA SN and 2 high resolution SN data series fall on the same day as the low of the adjusted solar flux, while the ISN is quite close. Above that, the high-resolution sunspot numbers show a more than remarkable correlation with the flux numbers, which leads to the question: is the solar 10.7 flux a mirror of the axial dipole field?
Patrick Geryl
added a research item
When did Solar Cycle 25 start? Patrick Geryl and Jan Alvestad developed a new theory to calculate the start of a new sunspot cycle. Determining the start of a solar cycle is one of the most followed questions in astrophysics because it may be important to professionals like astronauts, astrophysicists, engineers responsible for protecting the power grid, etcetera.The latest NASA prediction panel considers April 2020 as likely to become the starting month of the new cycle. The authors disagree and point to October 2019 as a central point to calculate the start. Why? Since 1947 a radio telescope in Canada has been measuring solar flux. The authors found something peculiar: in most of the previous 6 cycle transitions, the lowest daily solar flux values were near 64. The new solar cycle started a few months before or after these clusters of minimum values. In October 2019 there was another cluster of measurements below 66. A preliminary conclusion was that Cycle 25 was going to start between August 2019 and January 2020. Co-author Jan Alvestad has a widely followed website Solar Terrestrial Activity Report and maintains high resolution sunspot counts based on images from the SDO NASA spacecraft. If you look (indirectly) at the Sun with telescopes, most days will be spotless near solar minimum, and those spots that can be observed are small and usually disappear quickly. However, there are plenty of tiny spots in high resolution images. For instance when other observers using traditional resolution telescopes see 1 sunspot at minimum, Jan Alvestad observes and documents 4-6 times more at the highest image resolution. Full text for viewing only. Copy link on email and it works. SharedIt link: [https://rdcu.be/b5woP]
Jan Alvestad
added a research item
In our previous article we found a relationship between the adjusted solar flux and the start of sunspot cycles. We used the 13 month smoothed average for it. Building further on this we found a surprising proof that sunspots and the adjusted solar flux are even more related. If we replace the standard smoothing formula with a 365 days smoothed average, some at first sight unbelievable coincidences turn up in the cycle 24-25 transition. The lows from NOAA SN and 2 high resolution SN data series fall on the same day as the low of the adjusted solar flux, while the ISN is quite close.
Jan Alvestad
added 2 research items
After analyzing the lowest adjusted 10.7cm solar flux values, we find that the adjusted flux for October 2019 is low enough to give the start of Solar Cycle 25 between August 2019 and January 2020. Further findings point to November-December 2019 as the starting date for Solar Cycle 25, while the 2K high resolution sunspot number points to December 2019.