As most everyone knows, especially those on HF experiencing poor reception, we are in a very deep solar minimum, being described as a century-class event (Link) as confirmed by NASA (Link).
Other notable lows include:
- 50 year low in solar pressure
- 12 year low in solar irradiance
- 55 year low in solar radio emmissions
So what is in the future? We may be able to see what the future brings by using hindcast of past data and observations.
We can see here that there was a huge minimum in the 1600 to 1700 known as the Maunder Minimum, just after 1800 - known as the Dalton Minimum, then in 1900 there was a dip, but not deep enough to warrant a designation. Could there be a pattern of deep minimums every 200 years (approximate 1600, 1800, 2000)?
Is this cycle periodic? Another plot based on changes in C14 levels may give us a clue.
(BP = Before Present)
We see other incidences of minimums - Sporer Minimum, Wolf Minimum, and the Oort Minimum. We also see what is referred to as the Medieval Maximum (a period of above normal temperature), and what is being referred to as the Modern Maximum.
If one tries to visually 'average' this cycle as a wave, we can see a cycle that rises to the Medieval Maximum then bottoms out the Sporer and Maunder Minimum, and then back to the Modern maximum. Notice that the deep minimums are still about 200 years apart, more or less.
By projecting from past cycle data, me may anticipate what the future may bring. Are we heading into a protracted minimum? What is the impact on Amateur Radio (HF reception)? Is this actually a good thing or bad thing?
Here is an item that discusses the possibility of a Dalton Minimum Repeat (Link)
"Still, something like the Dalton Minimum — two solar cycles in the early 1800s that peaked at about an average of 50 sunspots — lies in the realm of the possible, Dr. Hathaway said. (The minimums are named after scientists who helped identify them: Edward W. Maunder and John Dalton.)". David Hathaway, a scientist at NASA’s Marshall Space Flight Center.
http://www.nytimes.com/2009/07/21/scien ... .html?_r=2
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Originally Posted by ad4mg
