We’ve been watching the progress on the WUWT solar reference page in this plot from Dr. Leif Svalgaard:
Solar Polar Fields – Mt. Wilson and Wilcox Combined -1966 to Present
Leif Svalgaard – Click the pic to view at sourceNow, NASA has decided to call the flip. Video follows.
Something big is about to happen on the sun. According to measurements from NASA-supported observatories, the sun’s vast magnetic field is about to flip.
“It looks like we’re no more than 3 to 4 months away from a complete field reversal,” says solar physicist Todd Hoeksema of Stanford University. “This change will have ripple effects throughout the solar system.”
The sun’s magnetic field changes polarity approximately every 11 years. It happens at the peak of each solar cycle as the sun’s inner magnetic dynamo re-organizes itself. The coming reversal will mark the midpoint of Solar Cycle 24. Half of ‘Solar Max’ will be behind us, with half yet to come.
Hoeksema is the director of Stanford’s Wilcox Solar Observatory, one of the few observatories in the world that monitor the sun’s polar magnetic fields. The poles are a herald of change. Just as Earth scientists watch our planet’s polar regions for signs of climate change, solar physicists do the same thing for the sun. Magnetograms at Wilcox have been tracking the sun’s polar magnetism since 1976, and they have recorded three grand reversals—with a fourth in the offing.
Astronomers at the Wilcox Solar Observatory (WSO) monitor the sun’s global magnetic field on a daily basis. WSO home page
Solar physicist Phil Scherrer, also at Stanford, describes what happens: “The sun’s polar magnetic fields weaken, go to zero, and then emerge again with the opposite polarity. This is a regular part of the solar cycle.”
A reversal of the sun’s magnetic field is, literally, a big event. The domain of the sun’s magnetic influence (also known as the “heliosphere”) extends billions of kilometers beyond Pluto. Changes to the field’s polarity ripple all the way out to the Voyager probes, on the doorstep of interstellar space.
When solar physicists talk about solar field reversals, their conversation often centers on the “current sheet.” The current sheet is a sprawling surface jutting outward from the sun’s equator where the sun’s slowly-rotating magnetic field induces an electrical current. The current itself is small, only one ten-billionth of an amp per square meter (0.0000000001 amps/m2), but there’s a lot of it: the amperage flows through a region 10,000 km thick and billions of kilometers wide. Electrically speaking, the entire heliosphere is organized around this enormous sheet.
During field reversals, the current sheet becomes very wavy. Scherrer likens the undulations to the seams on a baseball. As Earth orbits the sun, we dip in and out of the current sheet. Transitions from one side to another can stir up stormy space weather around our planet.
An artist’s concept of the heliospheric current sheet, which becomes more wavy when the sun’s magnetic field flips. More
Cosmic rays are also affected. These are high-energy particles accelerated to nearly light speed by supernova explosions and other violent events in the galaxy. Cosmic rays are a danger to astronauts and space probes, and some researchers say they might affect the cloudiness and climate of Earth. The current sheet acts as a barrier to cosmic rays, deflecting them as they attempt to penetrate the inner solar system. A wavy, crinkly sheet acts as a better shield against these energetic particles from deep space.
As the field reversal approaches, data from Wilcox show that the sun’s two hemispheres are out of synch.
“The sun’s north pole has already changed sign, while the south pole is racing to catch up,” says Scherrer. “Soon, however, both poles will be reversed, and the second half of Solar Max will be underway.”
When that happens, Hoeksema and Scherrer will share the news with their colleagues and the public.
Source: NASA press release, h/t to Dr. Leif Svalgaard
VIDEO:
Related articles
- The solar cycle is still slumping (wattsupwiththat.com)
- Sun’s 2013 Solar Activity Peak Is Weakest in 100 Years (space.com)
RoHa says:
August 5, 2013 at 6:30 pm
“It means we’re doomed, right?”
-–—————————————
Always.
All the above was shown and discussed by David Archibald some time ago
Leif Svalgaard says:
August 5, 2013 at 6:55 pm
Leif, I’ve been meaning to ask your opinion on something, and this seems like a good time. If we are headed towards a Maunder-style minimum, what are your thoughts regarding as to how that would happen at the just over half a precession cycle old interglacial?
The premise for my question incorporates the parallel debate on just how long the Holocene will last, and considerable reading of the links that you post. Essentially I am asking what your thoughts are on the duration of the Holocene.
Thanks.
@ur momisugly Doug Proctor says:
August 5, 2013 at 5:15 pm
The article stated the wavy sheet is a better deflector of cosmic rays. Therefore, we should be seeing fewer clouds and more input of solar energy into the Earth’s climate system. Who knows, maybe the ocean’s just sucking it all in.
William McClenney says:
August 5, 2013 at 7:29 pm
Essentially I am asking what your thoughts are on the duration of the Holocene.
The slide into a new glaciation has always been slow and drawn-out so we are talking about thousands of years in the future. Not something we should worry about today. There are even arguments that the next glaciation will be longer off than usual, because the Earth’s orbit is becoming more circular.
“There are even arguments that the next glaciation will be longer off than usual, because the Earth’s orbit is becoming more circular.”
Leif, does that mean when there were no polar caps millions of years ago, earth had a different orbit?
Or was that because the earth was a bit closer to the sun then?
Leif says:
“…There are even arguments that the next glaciation will be longer off than usual, because the Earth’s orbit is becoming more circular.”
What about the size of that circular orbit? Will it be increasing because the sun is loosing mass over time?
Darnit, I can’t find the polar flip alert! 😉
http://www.swpc.noaa.gov/alerts/index.html
still frozen…Part of the reason for the ice free caps millions of years ago was the continental configuration. With North and South America separated by a shallow sea rather than the isthmus of Panama, there is thought that the ocean circulation patterns mixed the waters differently. (of course I would get a geologist to confirm that, as I am going by what I read in passing rather than something I have done a detailed study of. I likely have the mechanism off a bit.)
Leif, please elaborate on the graph, and its representative trends.
http://www.leif.org/research/Solar-Polar-Fields-1966-now.png
Thanks Owen.
“Leif, does that mean when there were no polar caps millions of years ago, earth had a different orbit?”
http://en.wikipedia.org/wiki/Milankovitch_cycles
According to this, both the North and South poles have crossed:
http://www.solen.info/solar/polarfields/polar.html
Doesn’t that mean the flip has already occurred?
The earth does experience field reversals, but they are quite different — not a regular cycle like the sun, but rather abrupt transitions that happen in intervals of 50,000 years up to millions of years. (see http://en.wikipedia.org/wiki/Geomagnetic_reversal).
still frozen in Canada, ldd says:
August 5, 2013 at 8:07 pm
Leif, does that mean when there were no polar caps millions of years ago, earth had a different orbit?
For the orbital mechanism to work other conditions have to be ‘just right’, such as the precise location of land masses and ocean currents.
noaaprogrammer says:
August 5, 2013 at 8:11 pm
What about the size of that circular orbit? Will it be increasing because the sun is loosing mass over time?
no, any mass changes are much too small.
OssQss says:
August 5, 2013 at 8:29 pm
Leif, please elaborate on the graph, and its representative trends.
It shows the polar fields measured at two observatories [Mt. Wilson (blue) and Wilcox (red), scaled to match when they overlap]. To eliminate an annual variation and any zero-level errors, I plot the difference between the North polar field and the South polar field. I also plot a ‘ghost’ of the field with its sigh reversed [shown in lighter colors]. That allows you to compare the trend more easily.
the Hermit says:
August 5, 2013 at 8:36 pm
According to this, both the North and South poles have crossed
The plot from Wilcox [and mine] is the one to consider. The notion of a sharp flip is incorrect, since the North and South poles change sign at different times. My plot shows the average difference [which flipped more than a month ago]. Another [equally valid] definition would be to say that the field has only flipped when the last shred of the old field has vanished. This may take another few months.
Richdo;
Is it just me or did this poor excuse for a sentence make anyone else’s head explode?
>>>>>>>>>>
I just read the AGU statement on climate change in the previous thread so my head was pre-exploded.
Leif Svalgaard;
there are even arguments that the next glaciation will be longer off than usual, because the Earth’s orbit is becoming more circular.
>>>>>>>>>>>>>>
Well that sounds like circular reasoning to me….
OK seriously, what is the reason for the earth’s orbit becoming more circular?
Hi Leif,
“There are even arguments that the next glaciation will be longer off than usual, because the Earth’s orbit is becoming more circular.”
Is this change a relatively recent thing, (a few thousands of years), or is it part of a long term gradual change in cycle from elliptical to circular?
Thanks
Peter
tchannon says:
August 5, 2013 at 6:17 pm
I posted an article on this from where you can find links to the original material.
In that article you show that you do not know what you are talking about. The strong annual variation is not ‘noise’ due to ground-based data, but a real effect coming about because the Sun’s axis seems to wobble back and forth by 7 degrees over a year, so that that we alternatively get a better view of the North pole [in September] and of the South pole [in March]. That allows us to actually deducing the distribution of the field over the polar cap as I show in this famous paper: http://www.leif.org/research/The%20Strength%20of%20the%20Sun%27s%20Polar%20Fields.pdf
Hinode is subject to the same variation which explains [should you care to read their paper] why they report observations from March and September.
davidmhoffer says:
August 5, 2013 at 9:09 pm
OK seriously, what is the reason for the earth’s orbit becoming more circular?
Perturbations by the planets, mostly Jupiter [yes, the planets are driving our climate].
Peter S says:
August 5, 2013 at 9:11 pm
Is this change a relatively recent thing, (a few thousands of years), or is it part of a long term gradual change in cycle from elliptical to circular?
This takes place on time scales of 50,000 years and longer.
A paper with more:
“Science 23 August 2002:
Vol. 297 no. 5585 pp. 1287-1288
An Exceptionally Long Interglacial Ahead?
A. Berger, M. F. Loutre
“Today’s comparatively warm climate has been the exception more than the rule during the last 500,000 years or more. If recent warm periods (or interglacials) are a guide, then we may soon slip into another glacial period. But Berger and Loutre argue in their Perspective that with or without human perturbations, the current warm climate may last another 50,000 years. The reason is a minimum in the eccentricity of Earth’s orbit around the Sun.”
Thanks Leif.
So what impact have past solar reversals had on earth’s climate?
None, huge, lost in all of the other noise and pseudo-randomness?
What, if anything, should we expect to see?
Mike Smith says:
August 5, 2013 at 9:46 pm
So what impact have past solar reversals had on earth’s climate?
None, huge, lost in all of the other noise and pseudo-randomness?
What, if anything, should we expect to see?
The reversals themselves don’t do anything. Any other solar influence seems lost on the noise.
Leif, thank you as always for your instruction on this site! Articles like these bring me back 40 years, to when I studied astronomy at the University of Illinois under Dr. Jim Kaler. Amazingly, he’s in excellent health and we still communicate! http://stars.astro.illinois.edu/
Polar field progression at a higher resolution here .