From: SOHO sheds new light on solar flares
After detailed analysis of data from the SOHO and GOES spacecraft, a team of European scientists has been able to shed new light on the role of solar flares in the total output of radiation from our nearest star. Their surprising conclusion is that X-rays account for only about 1 per cent of the total energy emitted by these explosive events.
This SOHO/EIT image records two huge solar flares that were detected in October 2003. (Click here for the movie and further details.)
Credit: ESA/NASA
Flares are sudden energy releases in the Sun’s atmosphere that occur when the solar magnetic field is locally unstable. When the magnetic field lines break and reconnect, large amounts of energy are released, accelerating the surrounding particles to almost the speed of light. The temperature of the flares can soar to millions of degrees. At such sizzling temperatures, much of their radiation is emitted as X-rays.
Not surprisingly, most flares are imaged and studied at X-ray or extreme ultraviolet wavelengths, since they are more difficult to observe and analyse in visible light. Although more than 20 000 flares occurred in the last solar cycle (1996-2007), only four exceptionally large ones were identified as contributors to the total solar irradiance (TSI), i.e. the light received at all wavelengths on Earth.
In an effort to calculate how much energy is actually contributed to the TSI by flares, researchers from the Laboratoire de Physique et Chimie de l’Environnement et de l’Espace (LPC2E) in Orléans (France), collaborating with Swiss and Belgium teams, have been analysing 11 years of observations from space.
The team analysed the record of X-ray data acquired by the US GOES spacecraft during the entire solar cycle to detect the flares and record the times of their peak activity. The scientists eventually selected about 2000 flares which occurred near the centre of the solar disc. They then turned to the PMO and DIARAD radiometers of the VIRGO experiment on board the ESA/NASA SOHO spacecraft for information about the overall solar radiation heading toward Earth.
The next task was to identify any small peaks in TSI caused by the flares. This task was complicated by the random ‘noise’ generated by the Sun’s turbulent atmosphere. In order to recognise the contribution due to flares alone, the team used a statistical method to superimpose X-ray and TSI data taken at short time intervals around the period when a flare occurred. In this way, they were able to remove the random ‘noise’ from the data.
“The problem was to recognise the overall output from flares, radiated simultaneously at all wavelengths and in the visible domain, despite the natural fluctuations of the solar irradiance,” said Matthieu Kretzschmar, researcher at the LPC2E and first author of the study in Nature Physics. “It is like looking for 1-metre-high waves, caused by flares, within a rough sea where there are 70-metre-high waves caused by natural fluctuations.”
“To solve this problem, we amplified the ‘one-meter-high waves’ using the ‘superposed-epoch analysis’ method. The idea was to temporally superpose the total irradiance light curves for several flares. Natural random fluctuations in the solar irradiance cancel each other out, but the fluctuations caused by the flares are added and amplified.”
A significant peak was apparent in the total solar irradiance using the method of Kretzschmar et al. (Click on the image for a larger figure and further details.)
Credit: Image from Kretzschmar et al.,(2010).
The analysis led to a surprising result: there was a significant peak in the TSI when a flare occurred. Not only was the total radiative output of the Sun sensitive to both large and small flares, but the total energy radiated by flares was found to be over 100 times greater than the energy that they radiate in X-rays. It turns out that X-rays contribute only a tiny part of the overall output of radiation during solar flares.
These results, obtained within the framework of the European Community’s SOTERIA project, will help to improve current theoretical models of flares and understanding of the variability in the solar irradiance that reaches our planet. They could also help to shed light on the behaviour of more distant stars, some of which may also host planetary systems.
“Many stars are much more active than our Sun and emit extremely powerful flares,” said Bernhard Fleck, ESA’s SOHO Project Scientist. “This new estimate of the energy distribution of solar flares suggests that such flares may be extremely bright in visible light as well as X-rays, possibly with dramatic consequences for any nearby planets.”
Related publication:
M. Kretzschmar, T. Dudok de Wit, W. Schmudtz, S. Mekaoui, J.F. Hochedez, S. Dewitte, “The effect of flares on total solar irradiance”, Nature Physics, vol. 6, pp. 690–692, 2010. DOI: 10.1038/nphys1741
Contacts:
Matthieu Kretzschmar
LPC2E: Laboratoire de Physique et Chimie de l’Environnement et de l’Espace
CNRS / Université d’Orléans, France
Email: matthieu.kretzschmar
cnrs-orleans.fr
Phone:+33 2 38 25 50 39
Bernhard Fleck
ESA SOHO Project Scientist
Science Operations Department
Science and Robotic Exploration Directorate, ESA
Email: bfleckesa.nascom.nasa.gov
Phone: +1 301 286 4098
For further information please contact: SciTech.editorial@esa.int
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OT but there seems to a bigger and bigger discrepancy between DMI and CT, Nordsex etc…
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.arctic.png
?
Its getting outright ridiculous……. storytime?
Re flares what has Leif got to say..this seems to completely contradict his previous?
Seems to be transient. Is it relevant to the bigger picture?
DaveE.
Interesting read… but is it me… solar flares pushing out a lot of energy… who would have tought that… having seen some amazing pictures of solar flares I was surprised by the looking for 1-metre-high waves, caused by flares, within a rough sea where there are 70-metre-high waves comment… I assumed it would have been the other way around… but is it really a surprise that X-rays represents only a small part of the total energy spectrum released by flares… mmmmm…. guess I must be having a bad day… although I did manage to translate their possibly with dramatic consequences for any nearby planets comment as SEND MORE MONEY OTHERWISE THE PLANET GETS IT!
“This new estimate of the energy distribution of solar flares suggests that such flares may be extremely bright in visible light as well as X-rays, possibly with dramatic consequences for any nearby planets.”
Really???? Sounds utter tosh to me. I have read the UNIPCC reports! We all know that the Sun has no significant effect upon the Earth’s climate. It’s a well known settled scientific fact. Of course, changes in solar output & variations in orbital mechanics, regular alignments of the planets with their associated gravitational effects, were most probably responsible for past climate changes, but these, what are at times unimaginable humungous natural forces, pale into insignificance when you take manmade CO2 (15ppm out of 390ppm) production into account! Respect the Facts as they say at the Royal Society!
In all seriousness though, this was a very intersting post I thought!
The study suggesting a big difference of the spectral energy distribution.
So way they present a time domain energy distribution instead of a spectral composition??
Dr Leif S. can you chip in?
ps: bloody cold in South Australia! Brrrr….
AtB. Your dig at the RS was well taken. When they changed their motto from nullius in verba to Respect the facts, they abandoned science. In fact, they had long since abandoned science, they just made it official.
DaveE.
It’s such a relief to read about scientists doing science using data and putting in hard work. Using data to improve models, and not models to disprove data. Marvellous.
Interesting. On a related subject, does anyone have a reference to the velocity of neutrons, from thermalised to fast, from Sun to Earth?
Mick says:
October 15, 2010 at 1:49 am
The study suggesting a big difference of the spectral energy distribution.
So way they present a time domain energy distribution instead of a spectral composition??
What is important is the very small amount of energy involved, some 20 parts per million, which is 0.03 Watt/m2 compared to the full TSI of 1361 W/m2. So, flares play no significant role in the energy budget of the Sun or in the energy the Earth receives from the Sun.
Recalling a post titled “Solar flares are teleconnected to earthly
radioactive decay on WUWT in August:
http://wattsupwiththat.com/2010/08/23/teleconnected-solar-flares-to-earthly-radioactive-decay/
And a lame follow up NIST/Perdue experiment announced in,
“More follow up on the solar-neutrinos-radioactive decay
story – experimental falsification found at:
http://wattsupwiththat.com/2010/09/27/more-follow-up-on-the-solar-neutrinos-radioactive-decay-story-experimental-falsification/
The original study involved longitudinal decay rate data of specific
isotopes collected by Brookhaven National Laboratory (BNL), and
at the Physikalisch-Technische Bundesanstalt (PTB) and a short term
study done at Perdue just before and during a flare on Dec 13, 2006.
The BNL/PTB data revealed slight but significant monthly and
seasonal variations in the isotope decay rates of silicon-32 and
radium-226.
The Perdue study indicated a transitory change in the decay rate of
manganese-54 beginning just before the December 13, 2006 flare.
The data analysis and observations were not
falsified by the later NIST/Perdue study of gold-198.
The European teams’ announcement here of an unsuspected
addition to the TSI by way of medium and smallish flares
found in 11 years of observational data is a huge step
forward in solar studies.
Recent solar activity predictions by old hands based on “old” data
and inflexible paradigms haven’t matched reality.
My point is the sun seems to do things not previously
suspected, modeled, or accounted for in various TSI
measurements when it pops off a flare.
One assumes these things have been happening all
along, and aren’t peculiar to solar cycle 24. They just never
got noticed before this.
Now, all we need is a certifiable link between changes in TSI
and various forcings that produce some sort of atmospheric
response here on Earth.
How does this 1% X-rays affect current theory on pulsars ?
Leif Svalgaard says:
“What is important is the very small amount of energy involved, some 20 parts per million, which is 0.03 Watt/m2 compared to the full TSI of 1361 W/m2. So, flares play no significant role in the energy budget of the Sun or in the energy the Earth receives from the Sun.”
.002% of the full TSI is not significant, but an increase of .035% to .039% in CO2 is.
I don’t think these findings are that surprising. Flares are explosions. Explosions in general, especially nuclear explosions, emit wide-band energy. (Think: “DC to Daylight, and Beyond”). So, asserting that visible light is emitted in these solar explosions is not surprising.
Finding that light is another matter, and that’s the contribution of this research.
It’s difficult to detect because most of the Sun’s irradiance is in the visible light spectrum and below, falls off rather rapidly above ultraviolet:
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png
A similar misconception occurs with sunspots, which are really magnetic storms surpessing the visible light flux from below. They look black to us because the surrounding photosphere is brighter. But if you isolated the sunspots in a dark environment, you would discover that they are actually much brighter than a welder’s arc light on Earth.
DJ Meredith says:
October 15, 2010 at 4:23 am
.002% of the full TSI is not significant, but an increase of .035% to .039% in CO2 is.
And what has that to do with flares?
@DJ Meredith
The flux at the Earth varies from 1435 W/sq m to 1345 W/sq m during the course of a single year (specifically the former in Jan and the latter in July).
My question would be “Do these small bursts in TSI integrate into any substantial number which effects the Earth’s radiation budget?” We always hear that TSI variations between solar max & solar min are very small – too small to be a significant influence on climate. So the root of my question is really if the variation in TSI might be bigger than has historically been thought due to these TSI bursts, which I assume are more numerous at peaks of solar cycles than in minimums.
Anyone with expertise care to comment?
> The flux at the Earth varies from 1435 W/sq m to 1345 W/sq m during
> the course of a single year (specifically the former in Jan and the latter in July).
… and the received solar flux at any point on Earth varies from 0 W/m2 to 1366 W/m2 during the course of a single day (assuming no moonshine).
So, 100% trumps 0.002%.
:-]
….Was just bringing up the issue of flares being viewed as insignificant v. TSI, which made me wonder why then would we be spending good, hard earned research time and money to study something as insignificant as solar flares??
Seems to be a lot of unwarranted interest in the effects on our ionosphere and things like communications, power grids, sensitive electronics being affected by something that’s only .002% of the TSI and the “energy budget”.
This reminds me of trying to find a regular tone-evoked response deep in the auditory brainstem (basically looking for a synaptic signal predicted to follow a tone pip) out of a background of far greater random ambient synaptic brainwaves that are picked up at the surface. In both cases, simple electrodes (low impedance cups attached at the end of wires sitting on the scalp) pick up both signals. The random cortical noise, being much greater in amplitude, buries the smaller brainstem evoked synaptic signal. To find the regular signal out of the random noise, an algorithm is applied that mathematically calculates random noise to near zero. Anything that is regular or repetitive (IE non-random) rises out of the zeroed ambient noise.
It is clear from this example, that the regular spikes of an evoked brainstem response do not contribute to the overall random amplitude of cortical noise. And so it would be with flares in the background of the much larger solar output. That’s why they must pinpoint the flares first, then look for a smaller evoked signal in a background of higher amplitude random output. There are lots of areas in my analogy that must be taken with a large piece of rock salt, but the similarities might help the reader understand that the emissions from solar flares cannot have an affect (in this case a driver of change) on our weather pattern variations commonly talked about as warming or cooling.
Jeff L says:
October 15, 2010 at 6:04 am
My question would be “Do these small bursts in TSI integrate into any substantial number which effects the Earth’s radiation budget?”
No, because they only last a few minutes each.
Let’s dig it deeper:
1.-You all will agree we are not fools.
2.-Then, if we are not fools, we can, rationally, to disentangle the tangle we are in from about 300 hundred years.
Now, let’s see:
-In the beginning there were only two things: The Force and the Void.
-As too many millions of years have passed while both were watching one to the other at the two sides of a dimensionless point,
The Force at Cos y= -1 and the Void at Sin y= 0,
Then the Force told the Void: Hey pal, we are getting really bored staying like this, two fools watching one another for the whole Eternity, let’s get move ahead a little, just to see what the heck happens!
-Thus, both started moving ahead, one, The Force, in the 10 O’clock direction and The Void in the 2 O’clock direction, both describing beautiful arcs to reach a place 45 degrees above its initial position.
-Then The Void told The Force: Hey, buddy, you look different now!, kind of something electric I can find now in your eyes, complexion and there is an electric halo surrounding you!; and The Force told the Void: Hey, buddy, you look different too!, it seems that there is something Magnetic about you now, hey!, you look really attractive!
-Suddenly a big and brilliant spark jumped up above connecting them in a kind of inseparable cosmic marriage.
-Then, both holding their hands together said to one another: Let’s keep on going to see what new marvels we find ahead!
-Both said: Let’s go then to reach that source of that new light which was born out of the two of us, to that light above, at the Zenith!
-So they started walking in the direction of the 12 O’Clock.
-There were just one foot of reaching that supreme point, when suddenly they heard a roaring Thunder from above and both trembling saw a giant and shining Shaking-Spear appearing, coming fiercely down from the Zenith: The Sound roared : You came together up to this forbidden point, where you have just created a Son out from both of you: I am Gravity, the blossom of your coming together, however I am destined to point always from the Zenith down and, with me, you have just gave birth Ground, Matter, over which you’ll walk over forever!. Look at me, behold how both of you surround all along me, the longinus spear, the caduceus!
–We are all but One and so we will stay forever: The force at one side, the Cos y= -1, The Void to the other, the Sin y=0, the Couple of opposites, the two loving partners, Electricity and Magnetism always in love of each other, at Cos y=- 0.7011 and Sin y=+0.7011, always at 90 degrees from each other, forever 45 degrees above their original position. I, Gravity, that living Spear whose purpose is for ever to stick you to the ground being almost the addition of both of you, the addition of 1 and 0, however though I have some affections and passions too, I only reach, on earth the 0.981 level, the difference being the inclination I have for you and because of you, dear parents.
For more on this, read:
http://www.scribd.com/doc/38598073/Unified-Field
DJ Meredith says:
October 15, 2010 at 6:50 am
Seems to be a lot of unwarranted interest in the effects on our ionosphere and things like communications, power grids, sensitive electronics being affected by something that’s only .002% of the TSI and the “energy budget”.
And it is only 0.002% for the few minutes the flare lasts. Flares do have great effect on the ionosphere, but the density of the ionosphere is less than a billionth of the lower atmosphere so even a small amount of energy can have effect. And as you say ‘sensitive’ things are affected. But when it comes to climate, the thermal inertia of the system [think ‘oceans’] is so great that flares are insignificant.
David A. Evans says:
October 15, 2010 at 2:03 am
AtB. Your dig at the RS was well taken. When they changed their motto from nullius in verba to Respect the facts, they abandoned science. In fact, they had long since abandoned science, they just made it official.
DaveE.
After my two pints down at my local with my choral colleague who works for the Wet Office failed to pursuade me of his puter science back in early March I think it was! He sheepishly said he would send me a link to the Wet Office’s website for me to read (prompted by his misses who clearly & rightly some would say stand by her man) whilst our for a walk at the weekend, he never did. Perhaps he forgot it! As to the RS, as many have pointed out before me as soon as someone says that one should Respect the Facts, it’s time to start looking for the Fictions. It’s a bit like the way a bead of cold sweat trickles down my spine when I hear a senior police officer say about a new controversial law, “innocent people have nothing to fear!” That’s when I get scared!
Enneagram says:
October 15, 2010 at 8:01 am
1.-You all will agree we are not fools.
Your argument limbs a bit already here.
But, may the Force be with you. You need it real bad.