Strong solar flare creates rare magnetic ripples in Earth’s atmosphere

Energy stored in twisted magnetic fields above sunspot group 2017 was released a as a strong X1-class flare at 12:52 p.m. CDT March 29. Powerful X-rays from the flare sent magnetic currents through Earth’s upper atmosphere minutes later. Credit: NASA

An fast, intense X1-class solar flare yesterday afternoon not only blasted a cloud of solar electrons and protons into space but also sent magnetic ripples across Earth’s upper atmosphere creating what astronomers call a magnetic crochet.


X1 solar flare on March 29, 2014

Normally it takes an average of 4 days for a cloud of fast moving solar particles called a coronal mass ejection or CME to reach the Earth. Fast ones moving at 620 miles per second (1,000 km/sec) arrive in about 42 hours. But energy levels rose so rapidly in yesterday’s flare that Earth’s atmosphere was affected only minutes after the onset of the storm.

How could something from the sun get here so fast? Well, it does everyday. Sunlight traverses the 93 million miles between Earth and sun in just 8.3 minutes. There are many forms of light from radio waves to visible light to X-rays. Flares are so powerful they kick out waves of light energy across the entire spectrum from radio to deadly gamma rays.

The Earth’s ionosphere, divided into layers D, E and F, begins about 37 miles high and extends nearly to space. Solar and cosmic radiation strips electrons from atoms turning them into ions, which respond to electrical and magnetic fields. Credit: Rutherford Appleton Laboratory

A burst of X-rays from sunspot region 2017 arrived 8.3 minutes after the blast and increased the electrical conductivity in the D and E layers of Earth’s ionosphere by stripping electrons from the atoms there, making electric currents flow more easily. Because moving electrical currents create magnetic fields, the flare caused a sudden jump or ripple of magnetic energy to pulse through the ionosphere. As the flare subsided, those layers returned to normal.

You can see for yourself how an electric current creates a magnetic field by holding a compass near an operating electric shaver or hairdryer. As you move the shaver back and forth, the compass needle will swing wildly as it responds to the local magnetic field created by the flow of electrons in the current.

Even though we can’t see them, magnetic fields have very real effects.

Magnetic crochets are rare because they only occur during large flares that peak quickly. They’re also typically recorded at locations where the sun is overhead at the time of the flare.

Just one more way the sun touches our lives. As for the particles propelled by the flare, most of them took off northward of Earth but a glancing blow is expected around April 1 when Arctic observers may see a nice show of northern lights during their rapidly diminishing nighttime hours.

Big sunspot livens up a quiet sun / Chance for auroras overnight Feb. 1-2

Sunspot region 1967 dominates the solar disk in this photo made late Jan. 31 by the Solar Dynamics Observatory. Credit: NASA

Sunspot group 1967 burst onto the scene on Jan. 28. Now it’s big enough to easily see with the naked eye through a safe solar filter. The group’s twisty, complex magnetic field has already ignited a significant M6 flare on the 30th with a 60% chance for more M-class flares in the next three days.

The expanding cloud of solar plasma called a coronal mass ejection caught blasting away from sunspot group 1967 on Jan. 30 photographed by the Solar Heliospheric Observatory. Credit: NASA/ESA

The Jan. 30 event kicked out a high-speed proton-electron soup called a coronal mass ejection, a part of which will graze Earth overnight tonight (Feb. 1-2) and may spark a northern light display at high latitudes. Of course there’s always a chance southern Canada and the northern border states of the U.S. will see some action, too.

Since there’s been such a dearth of auroras of late, I wanted to share this bit of potentially good news. I’ll post updates if the lights make an appearance.

Why no aurora last night? Here’s the scoop

Maybe you were expecting something more like this last night? Join the club. Credit: Bob King

Did you plan a vigil the past two nights in hope of seeing the northern lights? I know I did. Lost some sleep over it for sure. As it happened, the display never materialized. Yes, the expected brush with particle blast released by the Jan. 7 solar flare did blow by Earth, but only managed to stir up a nice show in Arctic regions like northern Norway and Finland during afternoon hours for U.S. time zones.

Since auroras in that part of the world are as common as doughnuts, I think we can say this outburst was officially a flop.

I spoke with Joe Kunches, space scientist at the NOAA Space Weather Prediction Center, this morning about the matter. When I first rang, he told me he’d have to call back because the staff was just going into a meeting about this very topic. Hopefully no heads rolled.

Kunches described the solar blast as an empty bottle. “There was nothing in it,” he said. Despite the fact that it made a direct beeline for the planet, there was no way for scientists to know the strength and direction of the magnetic field embedded in the particle cloud.”

The Solar and Heliospheric Observatory (SOHO) monitors the sun from the stable L1 Lagrange Point a million miles sunward of the Earth. The green swirls around the Earth represent its magnetic bubble called the magnetosphere. Credit: NASA/ESA/Steele Hill

“The CME (coronal mass ejection) was slower than the model suggested by 8 hours, which sometimes means that it will be weaker than expected,” said Kunches.

“This illustrates our biggest forecasting challenge,” he went on. “We can see the path but can’t know it contains a strong magnetic field pointing in the right direction by the time it arrives at Earth the way a forecaster knows the barometric pressure of a hurricane.”

What happens to the swirling, whirling cloud of subatomic particles released during a flare must rank a close second to chaos itself. Scientists make detailed observation with dedicated space observatories like SOHO, the Solar Dynamics Observatory and STEREO probes and then model the behavior of the incoming particle winds as best they can:

“Even if they’re right when it leaves the sun, there’s no guarantee it will be that way when it arrives,” said Kunches. CMEs can rotate and deform in unpredictable ways. The key to a solid prediction of auroras very much depends on the direction of the magnetic field within the cloud when it sweeps by Earth, a factor called Bz.

The interplanetary magnetic field, created by a wind of solar plasma entwined with magnetic fields, departs the sun in the shape of a gigantic spiral. As waves of varying strength, density and direction pass by Earth, our planet’s magnetic field occasionally hooks up with the sun’s, making auroras likely. Credit: NASA

Embedded within the sun’s plasma swirls are portions of its magnetic field. As that material – called the interplanetary magnetic field (IMF) – sweeps past Earth, it normally glides by, deflected by our protective magnetic field, and we’re no worse for the wear. But when the solar magnetic field points south – called a southward Bz – it can cancel Earth’s northward-pointing field at the point of contact, opening a portal. Once linked, the IMF dumps its baggage of high-speed particles into our atmosphere to light up the sky with northern lights.

The Jan. 7 solar gust arrived at Earth with a northward pointing Bz. With no coupling, nothing happened. Perhaps you’ve watched the real-time red trace on the ACE satellite’s Bz read-out. For most of the past two days that squiggly line has been “flat as a pancake” as Kunches put it, which did not bode well for auroras. At any time it could have dipped south but never did.

Click to watch a video of the solar wind linking up with Earth’s magnetic field behind the planet, sparking a particle cascade and auroras in our upper atmosphere.

While no method is absolutely guaranteed, I recommend the following sites to check before you get in your car and drive 100 miles to see an aurora:

* ACE Dynamic Plots – The red trace for Bz is the one you’re interested in. If the line dips well below the centerline to -10 or lower, auroras may be likely.
* Ovation Aurora - Simulation of the auroral oval (extent of aurora) based on live satellite data. Pay attention to the location of the red curve showing the southern extent of auroral visibility.
* Kp index – magnetic activity indicator updated every 3 hours. A yellow bar (Kp=4) is a good sign aurora might be visible from the northern U.S. and southern Canada. A red bar (Kp=5 or higher) indicates a larger storm and more extensive aurora.

By the way, Kunches says that the CME has blown by and doesn’t expect any northern lights for tonight, so catch up on your sleep. In the meantime, put on your philosophical cap and reflect about how much we really don’t know about the world. Always a great motivation to learn more.

Chance for auroras across northern U.S. tonight Oct. 8-9

A coronal mass ejection of CME was photographed by the STEREO Behind probe, which looks at the back of the sun not visible from Earth, during early afternoon Oct. 6. The telescope uses a special instrument called a coronagraph to block the solar glare. Click for a short video of the blast. Credit: NASA

An interplanetary shock wave possibly associated with an Oct. 6 coronal mass ejection (CME) blew by Earth this afternoon and sparked auroras at high latitudes. As of 6 p.m. CDT we’re in the middle of a minor G1 geomagnetic storm. Judging from the satellite images of the auroral oval, the “apron” of northern lights that spreads outward across the polar regions, skywatchers across much of Scandinavia are getting a good show.

UPDATE: The aurora is out right now (8 p.m. CDT) here in Duluth, Minn. I’ve also heard of another report of northern lights over Maine.

Dim but active aurora drapes the northern sky to 45 degrees altitude at 7:50 p.m. this evening. Credit: Bob King

Observers in the northern U.S. and southern Canada should be on the lookout for possible auroras this evening. NOAA forecasters are calling for a 25 percent chance of minor storms at mid-latitudes. Here in northern Minnesota, we’re at 100 percent; aurora now fills half the northern sky. Nothing dramatic just yet – lots of faint rays and an occasional band or two.

A plot of the aurora oval in the northern hemisphere made with the POES satellite at 7:45 p.m. CDT shows it expanding southward over Scandinavia and Canada. When activity is low, the oval shrinks to a small circle in the far north. As more particles stream in from the sun, the oval expands southward. Credit: NOAA

Just a quick note on the photo at very top. It was taken by the STEREO Behind spacecraft and provides a perspective on the sun impossible with ground-based telescopes. STEREO-B trails far behind the Earth as it orbits the sun, keeping an eye on the solar backside. A second STEREO Ahead probe monitors the Earth-facing hemisphere for complete sun coverage.

Good luck tonight!

Aurora alert tonight May 17-18, 2013

This map created with satellite data for 11:30 p.m. CDT May 17 shows the extent of the northern auroral oval, one of two permanent caps of aurora centered on Earth’s north and south geomagnetic poles. Normally the oval is small and snugged up over Hudson Bay. Tonight it’s expanded southward and could produce auroras across the northern border of the U.S. Click to see current oval. Credit: NOAA

If it were clear here in Duluth, I’m sure we’d be seeing northern lights. The Kp index, an indicator of magnetic activity around the Earth, shot up to “5″ or minor storm level around 11 p.m. Central time this evening (Friday). From the satellite plot, it appears the auroral oval extends across southern Canada almost to the U.S. border.

Since the aurora is quite high – around 60-200 miles – it’s visible a fair distance to the south of that line. In other words, northern parts of Minnesota, Michigan, Wisconsin, N. Dakota, Montana and Washington may get treated to the sight of northern lights overnight.

Sunspot region 1748 still has the potential for more solar storms. Since the group’s now becoming more face-on to Earth, additional flares could send CMEs in our direction. Another flare on May 17 sent material expected to arrive on the 19th. Credit: NASA

Be sure to take a look at the northern sky tonight for arcs and rays of aurora. As you might guess, the cause for this show lies with the recent X-class flares sunspot region 1748 has been pounding out over the week. Our planet was expected to get a glancing brush from a coronal mass ejection (CME) overnight from one of the recent blasts. Let us know if you see anything. And get ready for May 19 – Sunday – when another blast could spark an even more auroras.

Lizard Lemmon Comet loses tail, grows a new one

Comet C/2012 F6 Lemmon photographed on May 15 showing its bluish, ion tail (bottom) beginning to peel away from the comet. The dust tail sticks out to the left. A wispy, new gas tail is already growing above the departing one. Credit: Damian Peach

Solar winds snapped off Comet Lemmon’s ponytail this week and sent it reeling into space. Not to worry. Comets possess the remarkable ability, shared by many species of lizards, to grow new ones. A lizard loses its tail to distract and escape a predator; a comet because its charged atoms – called ions – interact with the breezy blasts of charged particles from the sun called the solar wind.

Magnetic fields in the solar wind tore off Comet Lulin’s tail on Feb. 4, 2007. You can clearly see it falling away in the bottom frame. Credit: Joseph Brimacombe

One day Comet Lemmon was minding its own business and then on Wednesday morning, one of its two tails underwent a “disconnection event”. Comets frequently grow two tails when they orbit near the sun – a pale yellow one of fine dust and a blue one of ionized (electrically charged) gas. The blue color comes from ionized carbon monoxide which fluoresces blue when excited by ultraviolet light from the sun. The larger particles in a comet’s dust tail have no electric charge and aren’t affected by the solar wind; they get pushed away from the comet’s head by the pressure of sunlight.

Charged particles from the sun – electrons and protons – plow through the solar system and continuously interact with comets creating picturesque kinks and ripples in their ion tails. Wrapped up into this electrical mix are solar magnetic fields with north and south-directly poles similar to those on a horseshoe magnet.

 

Invisible magnetic field lines are made visible around a bar magnet when you sprinkle iron filings around it. The sun’s wind likewise has lines of magnetic force embedded within it created by moving charged (electric) particles.

Electricity and magnetism go hand in hand. A spinning magnet creates an electrical field and an electric current creates a magnetic field. Every time you turn on a lamp, the wires inside the cord are looped by invisible but very real magnetic fields.

Solar flare eruptions like the powerful X-class flares earlier this week can direct huge clouds of magnetized (and electrified) clouds of gas called coronal mass ejections or CMEs into space. When one smacks into a comet, it can rip its tail right off.

Magnetic field lines bound up in the sun’s wind pile up and drape around a comet’s nucleus to shape the blue ion tail. Notice the oppositely-directed fields on the comet’s backside. The top set points away from the comet; the bottom set toward. In strong wind gusts, the two can be squeezed together and reconnect, releasing energy that snaps off a comet’s tail. Credit: Tufts University

Comets present obstacles to the solar wind. The magnetic field carried by the sun’s constant wind gets pushed back by the comet’s electrified gases causing it to drape and flow around the comet’s head. That’s what forms the streamlined blue ion tail in the first place. But when an especially powerful blast of wind blows by, it can elbow its way around the backside of the comet and reconnect with itself, releasing a burst of energy that snaps off the tail.

Diagram showing how a CME slams into a comet (B) to create a tail disconnection event, known in the biz as a DE. Soon enough the comet grows a new one (D). Credit: NASA

In a very real sense, Comet Lemmon experienced a space weather event much like what happens when a powerful solar wind reconnects streams around Earth’s magnetic field and reconnects on the back or nightside of the planet. The energy released sends zillions of electrons and protons screaming down into our upper atmosphere where they stimulate the air molecules to produce auroras. One wonders whether comets might even have their own brief displays of northern lights.

As the solar wind flows away from the Sun, it creates a spiral-shaped interplanetary magnetic field (IMF). Two to four sectors – where the field is pointed toward or away from the sun – spin out every solar rotation (27 days). Each sector Credit: NASA

It’s unclear what pinched Lemmon’s tail since all four large flares from sunspot group 1748 and their associated CMEs weren’t directed at Comet Lemmon.

Maybe the comet crossed a sector boundary where the magnetic field carried across the solar system by sun’s steady breeze changed direction from south to north or north to south. When it sped across the older field wrapped around Lemmon, the two once may have linked up in a burst of energy.

When a lizard loses its tail, it may gain its life, but still suffer for the trouble. For a time, its sense of balance is compromised and important fat reserves stored in the tail aren’t available. Comet Lemmon will be no worse for the wear. As soon as the old tail drifts away, a new one sprouts in its place, cooked up by the ever-steady sun.

Read more about tail disconnections HERE; check out a map for finding Comet Lemmon HERE.

A 3rd X-class flare rocks the sun

The latest X3.2 flare in far ultraviolet light at 8:16 p.m. CDT Monday evening May 13 (May 14 Universal Time) photographed by the Solar Dynamics Observatory. Credit: NASA

Solar activity’s been rising like nobody’s business. Two of the year’s most powerful flares fired off from the sun’s backside late Sunday and at least 8 spot groups speckle the sun’s white-hot surface today.

Another ultraviolet picture of the sun taken by NASA’s STEREO Behind spacecraft late on May 13. The flare looks like a giant spike because the brilliance of the explosion saturated the camera sensors. STEREO Behind orbits well behind Earth and sees a part of the sun’s backside not visible with Earth-based telescopes. Click to learn more about the STEREO probes. Credit: NASA

Now we can add a third strong X-ray class flare, an X3.2 that spewed a vast cloud of high-speed solar gases called a coronal mass ejection (CME). Lucky for Earth, it was directed – as the other flares were – away from our planet off the eastern edge of the sun’s disk.

The most energetic flare measured in the modern era occurred on November 4, 2003 during the last solar maximum. No one knows how truly strong it became since the sensors topped out at X28. But any flare in the X-category can affect everything from GPS satellites to radio communications, satellite electronics and even fry poorly-protected power grids.

The sun in normal white light late Monday with sunspot groups labeled. Region 1748 – site of the strong flares of the past few days –  is just coming into view at far left. Credit: NASA

Solar flares typically occur in sunspot groups where magnetic energy is concentrated. The  solar surface, which bubbles and churns like a monster pot of hot oatmeal, brings opposite magnetic fields (north and south poles) in contact with one another. When they reconnect, the sudden release of energy heats solar gases to many millions of degrees and blasts billions of solar electrons and protons into space as a CME.

The amount of energy from a big flare like the ones we’ve seen recently equals millions of thermonuclear (hydrogen) bombs.

A healthy CME (coronal mass ejection) in the wake of the most recent X3.2 flare late Monday. This photo was taken by the Solar and Heliospheric Observatory which uses a special mask to block out the bright sun to better photograph it outer atmosphere. Credit: NASA / ESA

The sunspot group responsible for all the current feistiness goes by the name of 1748; it’s just coming around to the sun’s front side. Though highly foreshortened because we’re peering at it along the extreme edge of the sun, you can tell it’s a big one. Let’s hope it kicks and sputters its way to a northern lights display without any serious damage to our favorite toys.

Earth’s skies may dance in auroral green St. Patrick’s Day

A solar flare in the early morning hours of March 15 CDT sent a cloud of high-speed subatomic particles called a coronal mass ejection toward the Earth. It’s expected to arrive overnight tonight through Sunday. A disk blocks the sun in this photo taken with the Solar and Heliospheric Observatory (SOHO), allowing a better view of the cloud. Credit: NASA / ESA

I’ve got green on my mind and it’s not because I’m Irish. On March 15 a magnetic filament – a strand of solar flame silhouetted against the sun’s brilliant disk – erupted in a long-duration flare that sent a blast of solar plasma directly toward the Earth. Traveling at 2 million miles per hour, the cloud of high-speed electrons and protons will slam up against our planet’s magnetic bubble and possibly touch off an auroral storm.

Auroral display over Duluth Oct. 8, 2012. The green color, the most common seen in northern lights, is caused by oxygen atoms in our atmosphere energized by high-speed electrons from the sun. When the atoms return to the “unexcited” state, each releases a bit of green light. Photo: Bob King

Minor auroras are forecast for mid-northern latitudes tonight March 16 with a chance for a major storm on Sunday. If you live in the Arctic, get ready for a good show – chances for a major to severe storm stand at 70% Sunday (20% for mid-latitudes).

Wide-field view of the same coronal mass ejection taken by SOHO around 3 a.m. CDT March 15. Venus is to the lower right of the sun. Credit: NASA / ESA

These are the best numbers I’ve seen in some time, so be on the lookout this weekend for green rays step-dancing across the northern sky.

As always, keep an eye on the Kp index and the extent of the auroral oval, both of which are useful indicators of auroral activity. If the Kp index bar is colored red (equal to 5 or more), there’s a good chance auroras are out at least for the northern U.S. and southern Canada.

As I write this in the wee hours of Saturday morning, the index is already rising and auroras appear to be pushing into the far northern U.S. If it wasn’t for a heavy snow falling, I’d go out for a look-see right now. More updates later today.

Pint-sized auroras possible this weekend Jan. 18-20

Jarno Pääkkönen of Finland took this photo of a very colorful northern lights display Thursday morning, Jan. 17, 2013 in Kontiolahti, Finland, latitude 62.7 degrees north. Details: Canon 5D Mark III camera, 20-25 seconds at f/4 and ISO 2000. Click photo to see more of his work.

A heads-up for all you aurora watchers out there. The NOAA space weather forecast  calls for a 30 percent chance for minor geomagnetic storms tonight Jan. 18 through the 20th. That means there’s a small possibility for auroras in the northern U.S. and a much better one for Arctic regions.

Thomas Kast, who also hails from Finland, shot this photo the same night near Rokua, Finland. “Northern lights are never boring!” he says. Kast had to walk through deep snow in -16 F temperatures to get the shot he wanted. Click to see more photos on his Facebook page.

The cause behind the next expected wave is another CME or coronal mass ejection. Similar enhancements in the sun’s wind of subatomic particles have been responsible for recent, widely-visible auroras across Finland, Norway, Iceland and Canada. We came close to seeing minor auroras in the northern U.S. last night, but the burst of activity that visited the Scandinavian countries earlier in the day had died down by the time darkness cloaked the U.S.

Give a look up if it’s clear this weekend, and if you see the northern lights, drop us a report by clicking on the Comments link below.

Sun blows Earth a kiss – will she blush?

Three views over 2 1/2 hours of a coronal mass ejection or CME as it burst off of the sun headed for Earth this morning Jan. 13, 2013. The images were captured by NASA’s Solar Terrestrial Relations Observatory (STEREO). Credit: NASA/STEREO

The sun hurled a coronal mass ejection (CME) in Earth’s direction this morning at 1:24 a.m. (CST). This proton-electron particle spray may reach us within 1 to 3 days and possibly make the Arctic sky blush with auroras. We’ll have to wait and see.

Since this CME left the sun at only 275 miles per second, it’s not likely to kick up a big storm. The biggest blasts can send particles our way at nearly ten times that. If they succeed in connecting with Earth’s magnetic envelope, the magnetosphere, electrons and occasionally protons spiral down along magnetic field lines into our atmosphere to produce auroras. We don’t have to worry about these guys hitting us directly on the ground; we’re protected by the planetary magnetic field and the air above us.

Saturn’s tiny moon Daphnis (the point of light) clears the 26-mile-wide Keeler Gap, named after 19th century American astronomer James Keeler, in Saturn’s rings. The gravity of the moon also creates the ripples seen along either side of the vacancy. Credit: NASA/JPL-Caltech SSI

One of my favorite things to do is dig through image archives looking for gems to share. A recent photo of Saturn’s 5-mile-diameter moon Daphnis raising sawtooth-like waves in Saturn’s Keeler Gap caught my eye. The picture, taken by the Cassini spacecraft last August and released in late December 2012, shows a lovely series of ripples on either side of the Keeler Gap, a debris-free zone about 26 miles wide near the outer edge of Saturn’s A-ring.

Closeup of Daphnis and its gravitational wake photographed by Cassini on July 5, 2010 from a distance of 45,000 miles.  Click to enlarge. Credit: NASA/JPL/SSI/ color composite by Gordan Ugarkovic

As it circles the planet on an inclined orbit, Daphis’ gravity tugs on the icy ring particles to clear a gap and create the ripples. The rings are only about 33 feet thick despite their vast extent and consist primarily of individual chunks of ice in their own slightly different but unique orbits about the ringed planet.

Although difficult to see in the picture, the ripples rise up about 1 mile above the ring plane. Notice there are two sets. Material along the inner edge of the gap orbits faster than the moon, so that the ripples precede Daphnis in its orbit. Material on the outer edge moves slower than the moon, creating a set of trailing waves.

Nature has many sculptors and tools with which to fashion the most delightful of cosmic structures. Put a smidge of a moon in the right place and it’s not long before something marvelous happens.