Were We There Yet ? Solar Minimum

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Were We There Yet ? Solar Minimum

Postby VK2ZRH » Wed Aug 05, 2009 11:08 pm

By now, anyone with even a modest interest in progress of the solar cycle knows that the current period of solar minimum is the "lowest and longest" since 1913.

The run of monthly sunspot numbers for the past year (indeed, 2.5 years) has led the solar science world on slow waltz to Armageddon (or so it seems), not to mention DXers, solar bloggers, climate change skeptics and other interested parties.

Taking the monthly smoothed sunspot numbers from January 2007 to December 2008, you can see where they took a dip, rose again after the dip - only to plunge relentlessly downward . . . no less than three times ! See Graph 1 below.

Smoothed SSN Jan07-Dec08.gif
Graph 1: Smoothed monthly sunspot numbers, Jan 2007 through December 2008. (Source: IPS)

Projections for the date (month) of the solar cycle minimum, from the various space weather agencies, have been pushed out time after time since 2007. The latest - from our own IPS Radio and Space Services - now has it as April 2010 :!: :cry:

See: http://www.ips.gov.au/Solar/1/6

Having prepared and given a series of presentations on the current solar cycle over the past 12 months, I decided to check the "3-monthly running mean" (a smoothing technique - no 'magic' to it) of sunspot numbers for the past year to see how things were going. The running mean is a way of showing trends in variable data.

The "gold standard" for sunspot number data is the Solar Influences Data Analysis Center (SIDC) in Belgium (http://www.sidc.be). SIDC issues a series of "relative sunspot numbers" (R), derived from data sent to them by 60-or-so observatories across the world. The numbers given by Tad Cook K7RA in his week ARRL Propagation Bulletin are generally from the US's Space Weather Prediction Center (SWPC) - one of the contributors to the SIDC data set. Our own IPS Radio and Space Services also issues monthly sunspot numbers, which closely track those issued by SIDC.

So I've graphed the 3-monthly running means for the period June 2008 through June 2009, for these three sources of sunspot numbers - and the results are intriguing, indeed. From the figure below, it appears we have two successive minima, six or seven months apart :!: - one in August last year, the second either in February (SIDC and IPS figures) or March (SWPC figures). :roll:

3-Month Running Means Graphed 08-09.gif
Graph 2. 3-month running means for sunspot numbers, June 2008 through June 2009. (Sources: SIDC, IPS, SWPC)

The one marked RI is the SIDC data; IPS is the IPS (Aust) data; and SWO is the SWPC (USA) data. The 3-month running means are marked with blue spots. Looking at the months around the "dips" in the blue spots, I've place a red bar, which is the mean of the three months across the dips. The vertical scale on each is the smoothed sunspot number running mean.

The SIDC graph (RI) shows the February minima to be lowest (1.1 compared to 1.3 for August 2008).

The IPS graph (IPS) shows the two minima to be the same, although the February figure has been round up (from 1.17 to 1.2), because we can only work to one decimal place.

The SWPC graph (SWO) shows the August 2008 minima to be lowest (1.6 compared with 1.8 for March 2009).

Were we there, yet :?:

Maybe. Remember, it looked like we were there several times before :mrgreen:

Perhaps we'll know - for sure - sometime in the last quarter of 2009. :roll: Or not. :lol:

Posted in the interests of intrigue.

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK4GHZ » Thu Aug 06, 2009 9:10 am

Roger, very interesting.

To be absolutely correct, isn't a complete "solar cycle" actually 22 years (nominal)?
Where the sun's magnetic poles flip every 11 years, and to get back to where it was, it would involve two of what is commonly referred to as a "cycle".

If this is the case, and given the fact that we saw a double-peak last time, would it be reasonable enough to consider this double-dip as an inverted mirror image to what transpired in the first half of this 22-year cycle?

:?:
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Thu Aug 06, 2009 9:28 pm

Hi Adam,
To be absolutely correct, isn't a complete "solar cycle" actually 22 years (nominal)?

By common scientific agreement since the 19th century, the solar cycle is defined by the rise and fall of sunspot activity. A new cycle begins at solar minimum, proceeds through the maximum and ends at the succeeding minimum. This is the convention adopted by solar scientists in the 19th century, and retained ever since.

The month of the solar minima is determined from the 12-month smoothed sunspot numbers, which only falls out of the calculations about 6 months after the 'fact' (because of the smoothing method).

The solar magnetic cycle, wherein the Sun's polar field reverses polarity every approx. 22 years, is a related but only a relatively recently detected phenomenon. The reversal happens around the time of solar cycle maximum (but not quite "in sync"). :?

Double-humped peaks are not new. Cycle 18 (1947-50) was a double-humper, as were all the cycles from number 20 (1969-70) onwards. Take a look at the long-run record of solar cycles here: http://www.sidc.be/news/113/welcome.html
. . . would it be reasonable enough to consider this double-dip as an inverted mirror image to what transpired in the first half of this 22-year cycle?

No. :mrgreen: Slice and dice the chicken entrails however you like, they're still . . . chicken entrails. :D

"Double-dip" mimina, as it turns out, aren't rare, either. :wink: Take a look at the minima which began Cycle 19 (with a smoothed peak SSN of 201.3, the largest on record) - which the Sun prepared earlier. :lol: I've plotted it in Graph 3 below.

3-Month Running Means Graphed 1953-54.gif
Graph 3. The minima that sparked Cycle 19 (3-month running means of monthly sunspot numbers). Source: SIDC.
3-Month Running Means Graphed 1953-54.gif (9.13 KiB) Viewed 1873 times

This graph is best compared with the top one in Graph 2 above.

Features of Graph 3 to note include: (a) the much wider range in monthly SN values compared with the current minima; (b) the pair of minima (red bars) only four months apart (compared with 6-7 months); (c) the red bullseye marking the 12-month smoothed sunspot minima: April 1954 (smoothed SN of 3.4).

Posted in the interests of maintaining interest in the solar cycle.

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK4GHZ » Thu Aug 06, 2009 10:08 pm

VK2ZRH wrote:By common scientific agreement since the 19th century, the solar cycle is defined by the rise and fall of sunspot activity. A new cycle begins at solar minimum, proceeds through the maximum and ends at the succeeding minimum.

Well, ok, but in AC theory I still reckon that would only be half a cycle. :wink:
Scientists can't be all that bad though... they made De Loreans, flux capacitors, and time travel popular. :D
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Re: Were We There Yet ? Solar Minimum

Postby VK2GOM » Thu Aug 06, 2009 10:43 pm

...but the 1.21 gigawatts (of course pron. 'Jig-a-watts') power requirement for the flux capacitor is sadly beyond capabilities of a panel on the govt's solar rebate scheme... 8)

And I'm going to go into Dick Smith one day and ask for a Flux Capacitor, possibly on April 1st, just for fun. If I can get them to at least look for it on their sales computer :lol:

And on a more serious note again, great data Roger, and interesting reading. Patiently waiting for the solar condx to perk up...

73 - Rob VK2GOM
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Re: Were We There Yet ? Solar Minimum

Postby VK2GOM » Fri Aug 07, 2009 9:36 am

Yes, that site is great... lots of entertainment. I found it a while back - and loved the Professor of Stock Car Economics, the herd of goats, and 'Tom Jones' with his 'Whats new pussycat' letter sign-offs 8)

The best though would have to be the guy who was on his way to the Western Union place to mail the money and faked his own death in a pedestrian accident on his mobile phone!

Plenty of fun there until the solar conditions pick up HI.

73 - Rob VK2GOM
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Sun Aug 23, 2009 3:41 pm

It seems, maybe, we weren't there, yet :!:

The latest ARRL Propagation Bulletin from Tad Cook K7RA tells us that, to 21 August, we had 42 spotless days in a row. :shock:
See viewtopic.php?f=43&t=8687

That puts this period in the top 10 of spotless periods since 1849. :cry:

Mind you, over September-October 1996 (pre-Cycle 23), we had a run of 37 days. See http://www.ips.gov.au/Educational/2/2/7

So far, during this trough between solar cycles, we've seen a collection of spotless days in the 20s and 30s, all studiously recorded here: http://users.telenet.be/j.janssens/Spot ... tless.html

So, this run of 42 spotless days (which may grow . . .) will pull down the smoothed sunspot number for July and August. Even so, a rise in the number of spots over the next 6 weeks will pull it up again. :wink:

All the while, the total of spotless days accumulate relentlessly. Owen VK1OD will have to update his "Spotless days around solar cycle transition" web page. [http://www.vk1od.net/propagation/solar/spotless.htm]

That's the trouble with examining chicken entrails, when you think you're come to the end, you find there's yet another length there. :lol:

Posted in the interests of maintaining interest.

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK6ZRY » Sun Aug 23, 2009 4:44 pm

Spotless days since 2004 was 696 days, and 485 days is a normal period.
Coronal holes send out protons in a stream, with luck towards Earth, they haven't disappeared as yet.
The solar wind has waxed and waned buffeting the planet causing Auroras and providing good HF paths.

The Sporadic E season in the northern hemisphere has been quite good with trans Atlantic paths so far, sadly no TEP for Hams.

So all in all it's been fair, sadly however the regular openings down-under during winter seem to have been absent.
My HF has been down a little in recent days, but I hope it will pick up, I still spot 17,800KM stations using 1 watt.

But I do miss 50MHZ, let us hope the R1 stations in Russia and China never disappear as our fav beacons.

Such a long period of little or no sunspots is really unusual, forget trying to set a date for a minima, it doesn't
mean anything to regular hams.

We just adapt and get on with life, counting the days is really fruitless. Change your mode, find some other way
to make contacts in radio, phone contacts are a relic of the past.
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Re: Were We There Yet ? Solar Minimum

Postby VK4ABW » Mon Aug 24, 2009 8:51 am

vk6zry wrote:Spotless days since 2004 was 696 days, and 485 days is a normal period.
Coronal holes send out protons in a stream, with luck towards Earth, they haven't disappeared as yet.
The solar wind has waxed and waned buffeting the planet causing Auroras and providing good HF paths.

The Sporadic E season in the northern hemisphere has been quite good with trans Atlantic paths so far, sadly no TEP for Hams.


no TEP :?: your kidding me.
The 49 tv has been weak for some time now but it is still there. The JA beacons have been spotted this year and a few openings to JA have occurred during the WSSP and SSSP's this year and last, all with a SFI around 65 - 68. :wink:
Just because the numbers are down doesn't mean the TEP stops. :roll:
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Sun Aug 30, 2009 11:01 am

The latest ARRL Propagation Bulletin No.35 (at: viewtopic.php?f=43&t=8700) records 48 spotless days up to 26 August. :(

From the Solar Influences Data Center, it seems we may be able to add another two days - so, totalling 50 spotless days in a row. :shock:

As the Pope asked of Michalengelo when painting the Sistine Chapel: "When will you make an end?" :mrgreen:

There were 54 spotless days between 16 Feb and 18 April 1879, the third-longest period since 1849 (when reliable continuous records begin).

Is this the way Cycle 23 is to end - not with a bang, but a whimper ? [Apologies to T.S. Eliot] :wink:

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Mon Aug 31, 2009 7:27 pm

OK - make that 52 spotless days in a row, now. :roll:

The SIDC daily bulletin for 30 August gave that day's estimated sunspot number as 0, based on 10 stations' observations.

The same bulletin gave the estimated sunspot number for 29 August as 0, based on 21 stations' observations.

This reminds me of a quote from the Goon Shows:

Henry Crun:"Oh dear, Min."
Spotty Minny Banister: "What . . . what is it, Henry?"
Henry Crun: "The wick in the engine's gone out !" :mrgreen: :mrgreen: :mrgreen:

Anyone prepared to take a punt on which day the next spot appears ? C'mon guys - this is a great Australian sport :!:

Name a day. No squibbing by saying "it'll be between this date and that date".

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK3BJM » Tue Sep 01, 2009 11:04 am

Well, while we're coughing up quotes... From "the Fireball Of Milton Street", in which it is discovered that the sun is on fire, and Seagoon & Co build a wooden rocket in order to put the fire out. In the concluding moments, just prior to lift-off:

Seagoon: Press the sulphur and light the old wick there. 5, 4, 3, 2, 1 -

Grams: [Explosion]

Grytpype: Oh dear, oh dear. After all that work. It's sad, Mor-I-arty, it's sad. However, let's count the money. 10, 20, 30... [both giggle evilly]

Moriarty: Oh dear, those poor fools.

Grytpype: Yes.

Moriarty: A wooden rocket, a wooden rocket! I ask you! Trying to put out the fire on the sun!

Grytpype: Yes.

Moriarty: They deserved to die, didn't they?

Grytpype: Yes they did, Mor-I-arty.

Moriarty: Oh, 25, 26 million, 28...

Grytpype: Moriarty, hasn't it gone dark?


Seagoon has succeeded at last? :P

How about Friday 4/9/09? Bidding's got to start somewhere...

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Re: Were We There Yet ? Solar Minimum

Postby VK4ABW » Tue Sep 01, 2009 1:41 pm

I've counted the chickens on the roof twice,
checked the weather gauge once,
and flipped a coin....
25th September 2009 :roll:
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Re: Were We There Yet ? Solar Minimum

Postby VK4EKA » Wed Sep 02, 2009 9:28 am

I guess by now you are talking about the spot after 1025 that turned up on 31st August.
Perhaps Barry is right with 4th Sept.
That would be a change because 1025 is likely to still be visible, two spots at the same time?
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Wed Sep 02, 2009 8:55 pm

Has the (spot) drought ended ? Wait for it . . . wait for it . . . :roll:

Active Region 1025 turned up "late" on 31 August. Not yet a spot, or spot group. :?

Here's an extract from the Solar Influences Data Center bulletin for 1 September:
SIDC SOLAR BULLETIN 01 Sep 2009, 1124UT
A new active region, NOAA AR 1025 appeared on Aug. 31st approximately at 40E 20N.
TODAY'S ESTIMATED ISN: 008, BASED ON 07 STATIONS.
FOR 31 Aug 2009 ~ ESTIMATED ISN: 000, BASED ON 32 STATIONS.


Just for backup (to be sure, to be sure . . . , Eccles), here's the Big Bear Solar Observatory's take on the events:
BBSO Solar Activity Report 01-SEP-2009 15:21:47 UT
A new region formed late yesterday. The region is small and from the new cycle.


Here's the Big Bear image:
Big Bear Solar magnetogram 2Sep09.gif
From www.solarmonitor.org/index.php

We have to await confirmation :roll:

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK4GHZ » Wed Sep 02, 2009 9:35 pm

VK2ZRH wrote:We have to await confirmation

Huh?
Confirmation of what they observed?
Don't they believe their own eyes? !!!! :lol: :roll: :wink:
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Thu Sep 03, 2009 8:41 am

You may have noticed that SIDC are the arbiters of "was that a spot?", requiring an assembly of observations from around the world to confirm the "status" of an "active region". :roll:

Until enough observers report the same thing, it's "provisional". :wink:

If it disappears in half a day, maybe it wasn't there long enough to gain true spot "status". :|

Such is the stuff of solar science :lol:

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK4ABW » Thu Sep 03, 2009 8:42 am

VK4CP wrote:
VK2ZRH wrote:We have to await confirmation

Huh?
Confirmation of what they observed?
Don't they believe their own eyes? !!!! :lol: :roll: :wink:


You know how it goes Adam.....check, recheck, verify, reverify, counter check, ask your 3rd removed cousin for his opinion......then publish it with clauses stating that your pretty sure but just want 1 more opinion on it :roll:

so...i guess my guess for first spot still stands :?:
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Sun Sep 06, 2009 10:45 am

So the run of spotless days ended late on 31 August, which makes Barry VK3BJM the winner of the "guess when it will end" bet :D

Active region 1025 appeared late on 31 August and fizzled out the next day. The daily SSN for 31/8 and 1/9 was assigned 12 (one group, two spots).

Barry reckoned 4 September.

At 52 spotless days in a row, the July-August 2009 period just sneaks into 4th place in the great runs of spotless days since 1849 league table, pushing out 17 March to 4 May 1902. See: http://users.telenet.be/j.janssens/Spot ... tless.html

Anyone willing to bet if we'll beat this run of spotless days some time in the next, say 12 months? :roll:

You don't have to guess how many spotless days (it may only be 53, after all !), just that you reckon there'll be a longer run :)

We live in interesting times [ see http://en.wikipedia.org/wiki/May_you_li ... ting_times ]

Posted in the interests of maintaining interest.

73, Roger Harrison VK2ZRH
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Re: Were We There Yet ? Solar Minimum

Postby VK2ZRH » Sat Sep 12, 2009 9:37 am

Another week, another bunch of zeros. :|

Daily sunspot numbers for 3rd September through 9th September were zero, every day. I dunno how they work this out, but the mean for the week was zero. :wink:

Solar study satellites report no emerging sunspots on the far side of the sun and that pesky "active region no. 11025" that appeared over 31st August - 1st September has rolled around to our side again - and nuthin's doin'. :roll:

As the Pope reportedly asked of Michaelangelo, who was high on the scaffolds in the Sistine Chapel at the time, "When will you make an end?" 8)

In the Aussie spirit of betting on anything, who's willing to wager on the date this run of zeros will come to an end. :?:

Posted in the interests of maintaining interest. :mrgreen:

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