Are We There Yet (solar min.) ?

This thread is now closed
Author Post

Roger, VK2ZRH

Sun Jul 26 2009, 01:41AM
The Australian Space Weather agency, IPS Radio & Space Services, has significantly revised its forecasts for the dates of solar minimum and Cycle 24 maximum, and the amplitude of the maximum.

From , updated Friday 24 July 2009:
IPS has made a significant change to its forecast for solar cycle 24. The forecast cycle maximum smoothed sunspot number has been dropped from 134 to approximately 90. In addition the time of maximum has been shifted away by one year to September/October 2013. These changes were made due to the protracted solar minimum currently being experienced, and the apparent statistical relationship between long solar minimums and lower following solar cycles maxima.

They've pushed out the date of the mimimum (effectively the start of Solar Cycle 24) to April 2010 !

That says that we'll spend the rest of this year and the first quarter of next year "bumping along the bottom" of the transition between Cycles 23 and 24. IPS has been the the last major agency to "hold out" on revising their forecast of the Cycle 24 peak downward.

Others, however, have different ideas. See: Dikpati, M. et al 2006 "Predicting the strength of solar cycle 24 using a flux-transport dynamo-based tool", Geophysical Research Letters, Vol. 33; and more recently: Dikpati, M 2008 "Predicting cycle 24 using various dynamo-based tools", Annales Geophysicae, 26, 259–267, 2008 (www.ann-geophys.net/26/259/2008/angeo-26-259-2008.html).

It's only in recent years that some solar cycle forecasting has been based on an understanding of the underlying physics of the solar cycle, rather than the variety of empirical methods based on statistical analysis of a group of past cycles (aka "reading chicken entrails").

Consider this: the minimum that began Cycle 19 (the largest on record, peak of 201.3) was a low one, with a smoothed sunspot number of 3.4 at April 1954. The monthly sunspot numbers were low (but variable) from November 1953 through August 1954 - nine months. The accumulation of spotless days prior to that miminum was 248 - the largest in the 70 years since 1940 . . . until now, where the number of spotless days has accumulated to more than 600 :(

My view ? Anything could happen

See also my earlier posting (Feb 2009):

73, Roger Harrison VK2ZRH




[ Edited Sun Jul 26 2009, 01:45AM ]
Back to top
Per, LA7DFA
Sun Jul 26 2009, 06:31AM
Per, LA7DFA
Registered Member #189
Joined: Sun Apr 06 2008, 04:05PM

Posts: 44
Thanks for posting the update Roger. Its only one year since the experts claimed they had found a reliable method to forecast the coming cycle by studying the internal dynamo of the sun. They predicted Cycle 24 would be 30-50% stronger than 23... We all know that every prediction after that has been lower and lower due to the long minima.

Like you, I would say anything can happen

[ Edited Sun Jul 26 2009, 06:32AM ]
Back to top
Roger, VK2ZRH
Mon Aug 10 2009, 03:46AM
Roger, VK2ZRH
Registered Member #844
Joined: Sat Feb 21 2009, 04:34AM

Posts: 3
Minimum, minimum - wherefore art thou ?*

From three sources of monthly sunspot numbers (SIDC - Belgium, SWPC - USA, and IPS - Australia), I calculated the 3-monthly running means for the period June 2008 through June 2009 - and the results are intriguing, indeed.

It revealed two successive minima. See the complete analysis, with graphs (and a following update) here (Were We There Yet ? Solar Minimum):

73, Roger Harrison VK2ZRH
[* acknowledgement to Shakespeare]
Back to top
Steve, VK3OT
Tue Sep 22 2009, 10:49AM
Steve, VK3OT
Registered Member #418
Joined: Tue May 20 2008, 10:10AM

Posts: 21
Wherever we are in the state of things it is not good.
We sure put a lot of effort into teasing out qso's over the VK-EU path from 1989 to 2003.
But it has all come to an end despite the willing and wishing.
It is back to what I remember as the normal, between my starting in 1963 and my first serious dx in 1978.
But it was another 11 years until 1989 to work europe from here.
And you must admit I made it work from here so it is not lightly that I say its not going to happen again so easily.
I spent hours each night hammering away on the key trying to break the path to Europe.
SOmetimes we got lucky.

I know its not going to happen using the same 'nouse and skills I used starting in 1988 December to work the heaps that I did.

With the closing of Analog TV in the next few years, the next question is what are you guys going to use as an early warning system?
Once the monolith 46.172 and then 46.240 close down there will be dead silence and nothing to alert u.

Here is the lifetimes work and effort


Back to top
Steve, VK3OT
Tue Sep 22 2009, 10:53AM
Steve, VK3OT
Registered Member #418
Joined: Tue May 20 2008, 10:10AM

Posts: 21
09/09/2009�� last qso 7.5 years ago.� Next QSO with EU due OCTOBER 2011/FEB 2012 and could be as late as Dec 2014.
SO on that scale using the time lines... here is my prediction.

CYCLE 22-23 EU DX PATH started in 23/12/1988 and came back in 31/12/2001 and it was 13 years between events.

On that scale
CY23-24 from 10/11/2001 could be expected to return in Dec 2014 and could also be 13 years between EU Openings.

Got any better ideas?
Back to top