Sun in deep slumber: 10.7 solar flux hits record low value

NRC's monitoring station

NRC Canada’s FTP site which logs the daily 10.7 centimeter (2800 megahertz) radio flux from the sun just reported what appears to be a new record low in the observed data.

64.2 at 1700 UTC

Source data is here

The Solar Radio Monitoring Program is operated jointly by the National Research Council and the Canadian Space Agency, the web page for their monitoring program is here.

The 10.7cm solar radio flux is an indicator of the sun’s activity. Here is a brief description of it from the National Geophysical Data Center:

The sun emits radio energy with a slowly varying intensity. This radio flux, which originates from atmospheric layers high in the sun’s chromosphere and low in its corona, changes gradually from day-to-day, in response to the number of spot groups on the disk. Radio intensity levels consist of emission from three sources: from the undisturbed solar surface, from developing active regions, and from short-lived enhancements above the daily level. Solar flux density at 2800 megaHertz has been recorded routinely by radio telescopes near Ottawa (February 14, 1947-May 31, 1991) and Penticton, British Columbia, since the first of June, 1991. Each day, levels are determined at local noon (1700 GMT at Ottawa and 2000 GMT at Penticton) and then corrected to within a few percent for factors such as antenna gain, atmospheric absorption, bursts in progress, and background sky temperature.

Solar Flux Image

Part of this has to due with the earth’s orbit and position relative to the sun in July, this from Australia’s IPS Radio and Space Services:

On July 18 1996, the observed value of the 10 cm solar flux dropped to a low of 64.9. In many books it is stated that the 10 cm solar flux can not go below a value of 67. For example, the formulae given in the June 1996 edition of the IPS Solar Geophysical Summary show 67.0 as the minimum value. So how can we get a value of 64.9?

The answer is quite interesting – it depends on the orbit of the earth! The earth’s orbit is not perfectly circular but is slightly elliptical. In July of each year we are a little further than average from the sun and so solar radiation, including the 10 cm flux, is very slightly weaker than average.

So the 10cm flux will tend to be lower in July than, for example, December when the earth is closer to the sun than its average value. The combination of the extra distance to the sun and the solar minimum conditions have acted to produce this very low flux value.

It is easy to correct for the earth-sun distance and, when this is done, a value of 67.0 is obtained. This is the text book value!

Values of the 10 cm flux are often given in two forms – first as directly observed values and secondly as values corrected for the earth-sun distance variation.

The last time that the observed 10cm flux was at a lower value was on July 26, 1964 when it stood at 64.8. The lowest value ever recored was on July 02, 1954 with a value of 64.4.

As we’ve seen from visiual cues and lack of sunpots recently, it is obvious that the sun is in a deep minimum. Expert forecasts that have called for the sun to be regularly active by now have been falsified by nature, and the question of the day is: how long before the sun becomes active again?

(h/t Basil)


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Were this an Associated Press article, it might headline

Bill Illis
Steven Hill

More like this
Man Caused Global warming of earth has caused Sun to change to deep slumber.


I do look frequently look on:
yep, looks weak, but not unexpected. I’m waiting for
something between 62 and 64 within the next three month.
Somehow, all of it reminds me of Eric Burdon’s song –
“When I was young” – with “The Animals”
… “it was so much colder then … when I was young”
… and it will happen again … unfortunately
2003, I paid about 1400 Euros for 5200 liters of heating oil,
… hmm, this year, I fear, I shall feel lucky to get same for 4700 Euros.

Pamela Gray

The trend to cooler continues as indicated by the weather station in Enterprise, Oregon. It is 9 degrees cooler than last year. When we should be baking in the hot afternoon Sun, it is only 79 degrees, with scattered clouds but mostly clear, and windy. The wind is cooler, leaving one with the impression that it is actually closer to 72 or so. The ozone layer is trending down over the western part of the US from a couple months ago. Hawaii has been under a thin ozone layer compared to the rest of the US. I have been watching the ozone slowly thin over that area, with the thin area getting larger and larger, almost hole-like.
Oh the terribly quiet Sun.

Gary Gulrud

Only de Shadow know.


So I’m confused now. The solar flux, according to theory, cannot fall below 67. According to the textbook, you can get a value of 64.9 because the Earth is at it furtherest from the sun.
Yet, we have a value of 64.2. Dies this mean that the earth is further away from the Sun than ever before, or is the theory now shown to be wrong? If the theory of how low the solar flux can go is wrong, what are the implications of this?
Alternatively, what is the possibility that this reading was incorrect?


I believe 67 is the minimum value you can have at a distance of exactly 1AU. Someone needs to publish what that translates to when Earth is at its maximum distance. We reached maximum distance from the sun on July 4th, I believe.


David: Actually, the AP headline will read:

crosspatch: The difference is 2.2 flux units, so 67-2.2 = 64.8, but the ‘theoretical minimum’ [67] is uncertain by about half a unit anyway, so one shouldn’t get hung up on the last decimal. For January, add 2.2.

Dennis Oliver

This comment is from Solar Cycle 24 (
Today the solar flux has dipped to a new low of 64.2. Just so you do not worry too much, on July 2, 1954 a value of 64.4 was observed. What followed was one of the strongest Cycles ever recorded (Solar Cycle 19).
So, should we put much confidence in this reading as a harbinger of a weak solar cycle?

Leon Brozyna

Interesting. I’ll take a wait and see approach on this to see how many years it’ll be before Hathaway adjusts the forecast for cycle 24. Just as long as the flux doesn’t stay this low for a decade or so. Things could start to get chilly…. Hmmmmm…low flux lasting longer than expected. Give it to the environmental movement to solve — they’ve already given us a consensus on AGW. It’s all those solar arrays damaging the desert environment and reflecting the sun’s power back at it. Give up electricity and live as one in harmony with nature.
On a serious note, given all the complexities of all the elements that impact the earth, how can anyone take serious anything Mr. Gore has to say.


That is a perfect headline. How about this?:
Gore: “Like I have said all along, the Ice Age is coming, and man’s use of fossil fuels are to blame.”
By Heidi Cullen

The plot shown in the post had a couple of deficiencies:
1) it should use the ‘adjusted for distance’ values [to show what the Sun is doing] and not the ‘observed’ values.
2) monthly means are not good for solar parameters as one month is close to the 27-day synodic rotation period of the Sun, but not equal, so that ‘beats’ will show up in the monthly means, giving the appearance of solar changes and ‘heaves’ that simply aren’t there. Better to average over 27 days.


“As we’ve seen from visiual cues and lack of sunpots recently, it is obvious that the sun is in a deep minima.”
I don’t think this article supports your position. Similar values have been recorded this century. Of course maybe you mean something else by “deep minima.”
REPLY: Your criticism is premature, of course your MO has always been to play “gotcha”. I meant only that it’s as “low as it can go” nothing else was implied. The currently believed flux lower limit is 67, the observed current value (after adjustment) is close to that.


The last 2 years were fun. Theories about the solar cycle, pause in global warming, tons of charts and stats about UAH, RSS, blablabla.
And now La Nina is over and the party is over too. Sorry folks.
Its strange the silence here about the massive ice cover lost in south hemisphere in the last weeks. And it’s winter in South hemisphere.
If we get an El Nino next year I expect skeptics and deniers quickly forget monthly data from the RSS and UAH 😉

Boris: I’ll second that. At every minimum the Sun returns to almost the same state [with only small variations from minimum to minimum] and this minimum is not exceptional. What is of interest is that cycle 24 has not yet begun in earnest, somewhat to the surprise of people predicting a very large cycle.
REPLY: Leif, you may want to reconsider that. agreeing with Boris is to agree with a premature conclusion. See my response to him. Note that I made no claims other than the observed value is a new record low, and that forecasts (particularly Hathaway’s) have been missed, leaving us all to wonder when the sun will ramp up again.


OK .. solar cycle 19 was one of the strongest on record. But from what I’ve read, and what I see on the records, solar cycle 18 was somewhat unremarkable. A typical looking cycle. It wasn’t a long stretched out minimal solar cycle like cycle 23 is shaping up to be.
So .. I don’t think the low solar flux of today is any indication of what cycle 24 will be like.
Looking at the historical record provided on Hathaway’s Article, it seems that the sunspot cycles follow a fairly smoothed curve, with some 9-10 cycles making up a cycle curve. Cycle 23 is the ninth and comming down from the peak of 1950 (cycle 19 was the fifth cycle in the curve). Also, I think the higher values for the cycles recorded over the last century is likely due to recording bias that has occurred due to advancing technology and changing definitions. I seriously doubt there were no “sun specks” during the Maunder minimum that would have qualified as sun spots today. I think Anthony has brought this up before as well.
I think this observation underlies the confusion regarding what the next cycle will be. Cycle 24 is at the trouph of the curve. It could be the end of this cycle, the dead bottom of the curve, or the beginning of the next curve. It could be smaller, equal to, or slightly larger than cycle 23. We’ll just have to wait and see.

Jerker Andersson

I doubt the radio flux can affect earths climate in any way. It is as far as I can see just an indicator of the suns activity, which currently is low.
What is more interesting is, what will solar cycle 24 be like? There seems to be predictions all the way from weak up to strong.
Some even say the sun may head into a new Dalton Minimum or worse.
Now, do we have enough knowledge of the sun to be able to predict a new Dalton or Maunder minimum?
If we do not have enough data to be able to predict a DM or MM, how do we know it is or it is not heading into one?
By the way, have NASA released a new prediction for when SC24 should start? I haven’t seen any yet.
The last 3 predictions failed with the last one saying SC24 would start in may.

Francois Ouellette

SS24: Link to data for southern hemisphere ice cover, please?

Francois Ouellette

SS24: I just don’t see what you mean:
Where’s the massive loss?


SS24 …
I don’t think I’d crow too fast. If you look at the cryosphere data, you’ll notice that there was a further melt off after this point in 2007, only to have the ice rise to record levels within a few more months.
Plus … couldn’t help but notice that you left out the NH data, where according to the “Tale of the Tape”, NH ice is still running a good 750K sq kms above this time last year.
Another thing you need to consider, La Nina doesn’t strengthen until the later months (August-Sept). While La Nina is gone now, it could very well re-emerge in the comming months. Most La Ninas are multi year events. The La Nina of 74 fell out of La Nina status for one month only to come back strong and last for almost another 2 years. The La Nina of 2000 also fell back from -1.5 to -.08, only to rise again stronger than the previous year.
As I’ve said on another site, we live in extraordinary times. A lot can be learned if people would take their colored glasses off and the MP3 players out their ears and observe!!

Jim Arndt

I agree not that special the sun has a lower limit, “we hope”. Some are very nervous due to that they predict a large cycle. My bet is around 60 to 65 not at the 40 some say. Your I believe is 75, correct. Chance of a large cycle is closer to a “Hail-Mary”, not impossible just not very likely.

Willem de Lange

I assume SS24 is referring to the continued break-up of the Wilkins Ice Shelf. You can see the daily sea ice status at
With regards to ENSO state – most predictions are for a neutral ENSO state for a few months yet. After that it is not clear: it could return to La Nina or develop into El Nino. We usually cannot make sensible forecast until August SSTs are available.

[…] compared to putting the Sun to sleep! Anthony Watts has the story, Sun in deep slumber: 10.7 solar flux hits record low value. Maybe this CO2 stuff is just as dangerous as Al Gore and James Hansen swear it must […]

Leon Brozyna

Jerker Andersson
Hathaway seems to be sticking with his moveable forecast for SC24. Here’s the compare-and-contrast graphic:


…there has been a small but statistically-significant increase in the overall extent of Antarctic sea ice. However, there are strong geographical variations at a regional scale. Sea ice cover has declined substantially in the seas to the west of the Antarctic Peninsula while it has increased in other parts of the Antarctic.
From, – (an interesting read)
I am guessing the silence here about the “massive ice loss” is due to absence of said “ice loss”.

Lloyd Graves

Please read this from Icecap especially note the piece from Richard Courtney who chaired the plenary session in Bonn in 1997 for the IPCC.
Wilkins Back in the News
By Joseph D’Aleo, CCM, Fellow, AMS
In another in an endless series of half the story articles, Livescience staff reported on the further fracturing of the Wilkins Ice sheet. “A vast shelf of ice in Antarctica is hanging on to the continent by a thread and is not expected to survive, scientists announced today. The entire Wilkins shelf, before the recent breakups, covered about 6,180 square miles (16,000 square kilometers – about the size of Northern Ireland).” (It should be noted the current total Antarctic ice extent is 13,000,000 square kilometers making Wilkins merely 0.1% of the total) and the ice is at a record extent for this time of year and appears headed to challenge or exceed last year’s record. It is mid-winter there now with 2 months more of ice growth.
See larger image
“Wilkins Ice Shelf is the most recent in a long, and growing, list of ice shelves on the Antarctic Peninsula that are responding to the rapid warming that has occurred in this area over the last fifty years,” said David Vaughan of the British Antarctic Survey. “Current events are showing that we were being too conservative when we made the prediction in the early 1990s that Wilkins Ice Shelf would be lost within thirty years – the truth is it is going more quickly than we guessed.” This latest stage of the breakup occurred during the Southern Hemisphere’s winter, when atmospheric temperatures are at their lowest. One idea is that warmer water from the Southern Ocean is reaching the underside of the ice shelf and thinning it rapidly from underneath.
Richard Courtney, an expert peer reviewer for the Intergovernmental Panel on Climate Change who in November 1997 chaired the Plenary Session of the Climate Conference in Bonn responded “The suggested “idea” really is clutching at straws. Melting is induced by heat and fracture is induced by stress. The fractures are happening in winter. And winter is the season when temperatures are at their lowest and when ice growth is greatest. Unless there is direct evidence of the ice thinning then there is no reason to introduce any suggestion that the fracture of the ice bridge is related to higher temperatures. Indeed, the fact that the fractures are happening in the winter implies that the reverse is true: i.e. the most probable explanation is that large ice growth is providing stress to the ice bridge with resulting stress fractures of the bridge.”
By the way, UAH MSU showed among the past 30 Junes, June 2008 was the third coldest south of the Antarctic Circle. The Antarctic continent saw its third coldest June in 30 years, with temperatures averaging -1.53C cooler than the seasonal norm. Portions of Anarctica south of Australia were as much as 5.5 C (9.9 degrees Fahrenheit) colder than seasonal norms for the first month of winter. The low yesterday at the South Pole Amundsen Scott AFB was -95F.

JimA: mine is sitting at 71 today. As Hathaway, I change mine all the time
🙂 depending on what the average polar field is for the last several years.

Tom in Florida
Another graph with the base period of 1979-2000. Will someone PLEEEEEASE
explain the facination with this time period? I understand 1979 as a starting point due to satellites but what happened after 2000? Did they fall out of orbit? Did NASA defund the project? Did the science teams all die? I do not understand why, at this point in time, the average is taken from 1979 – 2007.

[…] We’ve killed the Sun! The Sun is in a deep slumber […]

[…] Tags: cooler, northern hemisphere, Sun Related Posts […]

Bill Illis

By the way the global warmers are glorifying the Wilkin’s ice shelf break-up, you’d think there has never been an iceberg (broken-off pieces of ice shelves of course) in the southern oceans ever before.


SS24, Google Earth is an awesome thing. You can get plug-ins for it that will show you real time ice cover, clouds, local temperature and SSTs. Really awesome and amazing stuff from a wide variety of scientific organizations. I highly recommend that you download Google Earth and a variety of Weather plug ins before you make sweeping statements of Ice Cap loss. It’s free and in the future you can be more certain about the accuracy of your statements, that and you can monitor global warming in real time. Enjoy!


Positive Anomalies in Surface Temperature in South Pole, sometimes around +20ºC in the last weeks:


Anything that deviates from the norm and has Solar scientists scratching their heads makes precition re: the next solar Cycle pointless. I think we should be watching and learning instead of predicting at this point.


“And now La Nina is over and the party is over too. Sorry folks.
Its strange the silence here about the massive ice cover lost in south hemisphere in the last weeks”
Yeah, ENSO has pretty much returned to “neutral” but there is a more important change. When the PDO is in “warm phase”, the equatorial pacific tends to alternate between el nino and neutral with few la nina phases. When PDO is cold (like now), the equatorial Pacific tends tends to alternate between la nina and neutral. So looking at the current PDO … it seems more likely that we will return to another la nina than go into an el nino.
And yeah, Southern Hemisphere has returned to about average after having been +100,000 km. So in other words … there is no “massive loss of ice” so much as a loss of the substantially above normal ice and a return to average conditions. In yet other words … no massive reason to fear any significant reduction of Southern Hemisphere ice.

I wonder if there are bets on solar cycle 24 in Las Vegas?

SS24 (16:58:55) :
“Its strange the silence here about the massive ice cover lost in south hemisphere in the last weeks. And it’s winter in South hemisphere.”
I noticed it only yesterday when I was putting together a list of interesting links.
Ice cover hasn’t been lost – it is increasing, see What has been lost is the big anomaly, so ice has been forming more slowly than it has on average. I’m not sure what it all means, my first guess is that storminess has broken up some of the ice cover, but I don’t pay too much attention to it.
Frankly, I’m not too inclined to hunt down further information since you haven’t even bothered to check the standard sources.
“If we get an El Nino next year I expect skeptics and deniers quickly forget monthly data from the RSS and UAH”
Some will, some will use the data to look for new correlations or look for what’s behind the data. An El Nino would be nice, it would be interesting to see how they differ from El Ninos in positive PDO phases.


Found some cool graphs here today:
Still my favorite:
CO2 Rises, Arctic Ice Extent Grows………………..


This question is for Leif – I just re-read Hathaway’s 2006 prediction of a very low solar cycle 25 due to the slow down of the solar conveyor belt. (I’m sure you’re familiar with it) I of course know that we will just have to wait and see and take all predictions with a pound of salt (the ever changing start date to SS 24 being a good case in point) but I was wondering – from your work, do you think it is possible (not probable, simply possible) that Hathaway’s 2006 explanation was correct but that his timing was wrong? In other words, that the extremely low cycle he expected may be beginning now?
I know that Hathaway himself does not believe this is the case, but it looks to me like a possibility.


SS24, if you compare the SH anomaly from July 2007 to July 2008, there is slightly more ice than last year at the same time.

[…] Sun in deep slumber: 10.7 solar flux hits record low value […]


And I could see all I had done
Just chasing dreams across the fields
In the shadow of the sun


And the sun is gone
Forever out of this game
And the sun is gone
Her eyes will never be the same
She lost her soul
Caught in the demon’s eyes
She lost her soul
And there are no ears to hear her cries
The sun is gone

Hathaway and other NASA solar physicists are painting themselves into a tight corner. Clearly they do not know what they are doing, but cannot help but pretend that they do.


I wonder if there are bets on solar cycle 24 in Las Vegas?
24 Black


ESTRAGON: He should be here.
VLADIMIR: He didn’t say for sure he’d come.
ESTRAGON: And if he doesn’t come?
VLADIMIR: We’ll come back tomorrow.
ESTRAGON And then the day after tomorrow.
VLADIMIR: Possibly.