Category Archives: space weather

Solar Storm!

What You Should Know

The March 7th CME. Courtesy SOHO.

I see that “big” media has picked up on the idea of solar storms, in the wake of two most recent and very strong X-class events on the Sun. The headlines are breathless and I’ve already spotted some science bloopers on some sites that should know better (sites that used to have good science reporters, but who let them go in order to concentrate on important things, like Snooki’s baby).

Anyway, for all news about solar activity, I first turn to Spaceweather.com. The folks there have noted the impact of the coronal mass ejection was light at first, but warn it could pick up in the coming hours. Thus, people who live at high latitudes — northern regions around 50 degrees north or more — should get to see even MORE auroral displays than usual. If the storms get strong enough, those of us at lower latitudes might get to glimpse some aurorae, too.

All this solar activity is actually pretty much on schedule for the Sun. It goes through cycles of high and low activity, and we’re headed into a time of very high activity called “solar maximum”.  So, increased numbers of flares and coronal mass ejections and sunspots are part of this process.  It’s perfectly normal and nothing to get worried about. But, there will be the big media reports, and there will be some fascinating whack jobs tying this to something mysterious and paranormal.

Check out MIT Haystack Observatory's Space Weather FX vodcasts at the link below!

That, too, is perfectly normal and nothing to get excited about.

Space weather, which is a term that covers all the solar-caused and geomagnetic disturbances that occur in near-Earth space, does have its down sides.  While we gaze at lovely aurorae, giant disturbances in Earth’s uppermost atmospheric layers and nearby space can disrupt power grids, satellite communications, GPS signals, and many other bits of our modern technology. So, that IS of concern,  and during such events you will read reports that warns of GPS outages or communications outages due to space weather (solar storms). This happens because these bits of technology rely on radio signals which bounce off the layers of our atmosphere in order to propagate (travel) long distances on our planet. In the case of GPS, those signals go THROUGH the atmosphere.  So, if the upper atmosphere is disturbed by space weather, those signals can get broken up, delayed, or even lost. It’s an interesting and potentially dangerous side-effect of living near a star.

A while back we worked with MIT’s Haystack Observatory on a series of short videos about space weather. The series is called Space Weather FX. You can watch the whole series here and learn more about the effects that the Sun has on us and our technology.  Also keep an eye on Spaceweather.com for the latest and most accurate info on solar activity.

 

 

 

Our Eyes on the Sun

SDO Catches a Big One

The February 13, 2011 M6.6 solar flare. Courtesy NASA/SDO

If you’re cold, this picture should warm you up!  It shows a solar flare that erupted yesterday (February 13 at 17:38 UT).  It’s the largest such event so far in this current solar cycle (based on x-ray irradiance) and the strongest one so far in 2011.  The Solar Dynamics Observatory (SDO) caught the scene and flashed it up late Sunday. This amazing solar observatory was launched a year ago and has been sending back a steady stream of amazing images and data, all chronicling the activities of our nearest star.

Solar flares, coronal mass ejections and other actions are part and parcel of the Sun’s seethingly active surface and atmosphere, and these outbursts sometimes affect Earth and our technology. Hence, it’s important to study the Sun, if for no other reason to protect ourselves AND understand how the Sun affects Earth and its climate.  The Sun is currently ramping up in its 11-year cycle of activity, with the maximum period of activity (called “Solar Max”) to occur in 2013. This is a well-known cycle — and scientists are still working to understand all the nuances of activity that the Sun shows throughout the 11 years.

The solar flare you see in this image is a large explosion that occurred in the Sun’s atmosphere. It releases huge amounts of energy, particularly in x-ray and ultraviolet wavelengths. What powers a solar flare?  There is a huge amount of magnetic energy stored up in the corona.  Magnetic energy is stored up as magnetic fields twist and interact with each other. The process involvesd something called “magnetic reconnection”.

The Sun’s surface and atmosphere are threaded through with many lines of magnetic force. Those lines twist and turn, and rearrange over very quick timescales. Imagine a million tiny little rubber bands twisting and and twisting, and as they do, energy is built up. At some point, the tension is too much, and when two magnetic fields that have opposite “charges” or “polarity” are brought together, the fields snap.  That “snap” is accompanied by a huge release of energy. This magnetic reconnection is a complex situation and it happens very rapidly. X-rays and UV radiation is emitted, and that’s what SDO detected in the image you see above.

If the flare is big enough, the activity is also accompanied by a release of charged particles (plasma) and the event forms a coronal mass ejection.

The most obvious effect that this flare (and any coronal mass ejections) will have on Earth will show up as increased auroral displays at the polar regions.  Orbiting satellites and the International Space Station will detect radiation from the flare, as well.  As flares go, this one was pretty powerful (although not as powerful as an X-class, which would be quite dangerous).  We will be seeing its effects over the next few days. Stay tuned!

Update: People in the northern latitudes should see an auroral display tonight (Monday, February 14).  If you live in the northern tier of the U.S., Northern Europe, and areas north, you should keep an eye out tonight and tomorrow (Feb. 15).