“Hello?! Can you hear me?” Silence. The call has been dropped. Has this ever happened to you while trying to call someone? Bad connection, you might think. But could it be something else? The sun perhaps?
Did you know? The sun has just lived through an unusually quiet “solar minimum,” and we are now heading towards a “solar maximum,” which is expected to peak in 2013.
Even though the sun is nearly 150 million kilometres from the Earth, it still has a major effect on our lives. Almost two centuries ago, it was discovered that the sun operates on 11-year cycles. This means that every 11 years the radiation from the sun experienced on Earth peaks and the sun becomes very active.
The solar cycle is defined by the frequency and placement of sunspots on the sun. More sunspots equal increased solar activity.
The sun has a magnetic field, just like the Earth. The gas at the equator of the sun moves faster than at the poles. This causes the magnetic field to become more and more entangled.
Did you know? Sunspots are temporary dark spots on the surface of the sun caused by intense magnetic activity.
A solar flare usually occurs in active regions around sunspots when the energy stored in twisted magnetic fields is suddenly released in a huge explosion. High energy radiation (e.g. X-rays and gamma rays) and ionized mass particles from solar flares are cast off from the sun’s surface.
Another event due to magnetic activity on the sun are coronal mass ejections (CMEs). These are huge "bubbles" of electrically charged matter, known as plasma, which are ejected from the sun over the course of a few hours. Some CMEs are accompanied by flares, but the two phenomena are not causally related.Did you know? The northern lights, or Aurora borealis (Aurora australis in the south), are caused by solar storms resulting from CMEs.
So why the dropped calls?
Solar flares and CMEs can cause trouble with electric systems. Flares can temporarily alter the Earth’s upper atmosphere and cause disruptions in satellite communications. CMEs are typically more disruptive, and have been known to hit the Earth and knock out GPS signals, radio communications and even power grids.
So, knowing that we’re entering a Solar Maximum you might want to bring a physical map with you the next time you head out on a road trip—just in case your GPS is knocked out.
Solar Flares: What Does It Take to Be X-Class?
Sun Unleashes Largest Solar Flare in Years
Good news! Killer solar flare wont' destroy Earth!
How solar storms cause the Aurora borealis (video)
More on the Aurora borealis (pdf file)
Article first published November 14, 2011