Solar Flux Index fluctuations, where do they come from?

[NL7W]

I'd like to speak glowingly about the solar flux... guess I need to make a pilgrimage to Blarney Castle and kiss the Blarney Stone!

If it were only that easy...

Saw that too! Gadzooks!!! We're supposed to be nearing a peak and the flux is only 20 points above absolute zero. Blimey!!!!

[N0SYA]

Don't worry, old Sol's just saving up his solar junk to spew forth in one mighty rush that sends the earth back to pre ww2 society is all.

[K7MH]

We're supposed to be nearing a peak and the flux is only 20 points above absolute zero.

Yup..that was IT! On to cycle 25 now!!

[NM7L]

When there's too much flux, we like to say we want to get the flux out of here.

What the flux?!?

[WA9SVD]

All I can say is that Ol' Sol fluxxed us again, for Field Day weekend. The sunspot number dropped to 13, and the SFI was well below 100 (84, actually.) THAT stinks for DX. Even when some of the spots rotate back to face Terra (hopefully they WILL still be present in a couple of weeks) it takes several days of increased sunspot numbers for the SFI to start to increase significantly.

[N0SYA]

So instead of a solar maximum we get a solar minimum. Maybe the cycles have flipped?

[WA9SVD]

So instead of a solar maximum we get a solar minimum. Maybe the cycles have flipped?

Actually, that is a minimal maximum. Cycle 24 isn't expected to peak until 2013 (by "reliable" sources and best estimates.) I still hold out hope, and pray to the DX gods that last November wasn't the actual peak of the current cycle. Time will tell.

[WA9SVD]

So instead of a solar maximum we get a solar minimum. Maybe the cycles have flipped?

Actually, that is a minimal maximum. Cycle 24 isn't expected to peak until 2013 (by "reliable" sources and best estimates.) I still hold out hope, and pray to the DX gods that last November wasn't the actual peak of the current cycle. Time will tell.

[KA8JBY]

Regarding the 2-week periodicity: The sun has a roughly 27 day rotation rate, but it varies with latitude and is fastest at the equator. So when a big active region (sunspot group) rotates around the west limb (right side), the 10cm solar flux can drop depending on the distribution of regions. After about two weeks, the region can reappear on the east limb (left side), bringing the solar flux back up.

One of the first tools forecasters use to make the F10.7 flux forecast is recurrence - i.e. "What was the flux 27 days ago?" You can look back at the trends to see when flux might increase based on past behavior. You can also get an idea of what's coming around by looking at EUVI imagery from the STEREO-B spacecraft. - the bright areas are active regions, so more bright areas means more flux. To properly interpret the STEREO-B imagery, you need to know where STEREO-B is located relative to the sun.

You can find a flux forecast here, but use it with caution - the skill goes down as you move away from a 1-2 day forecast. You can find verification statistics for previous years at SWPCs website.

F10.7 flux forecasting remains an area of active research.

Cheers,
Rob
KA8JBY

[N0SYA]

"F10.7 flux forecasting remains an area of witch doctors."