[OKDXA] New Solar Cycle

[Kim Elmore]

I think the confusion about when a new cycle starts is due to a 
reliance on the smoothed sunspot number (SSN). The SSN is a 12 month 
moving average. That means that the SSN we get today is *centered* on 
a date six months ago. That's where the idea that we don't know when 
the minimum occurs until 6 months later.

There are other definitions of when a cycle begins and my 
understanding is that these depend on when new sunspots appear in the 
mid latitudes with a leading magnetic polarity opposite from the 
sunspots. That appears to be what has happened with AR981. It formed 
30 deg away from the solar equator with a leading magnetic polarity 
opposite that of previous groups.

Think of sunspots as bar magnets oriented E-W. In Cycle 23, the East 
end of the bar magnet in the Northern hemisphere is N while it's S in 
the Southern Hemisphere. When Cycle 24 arrives, this pattern will be 
reversed. That appears to be what is indicated in AR981. So, bay that 
definition, Cycle 24 appears has begun. We won't see it in the SSN 
for some months yet.

Kim Elmore N5OP

At 06:06 PM 1/6/2008, you wrote:
>I also thought that we really didn't know when a new
>cycle started until 6 months or so after it started.
>
>73s John AA5JG