Tuesday, January 24, 2012

CME Events - How They Affect Your Life

Let's switch briefly to the interface between Earth and Space. Specifically, the probably-novel-for-most-people idea of "space weather."

Two days ago, something not unknown, but not commonplace either, happened on the surface of the Sun. Something called a Coronal Mass Ejection (CME) event took place. These are complex phenomena, still rather poorly understood, but involve the Sun's powerful magnetic field and the huge energy being generated by hydrogen fusion. The result is a huge ball of ionized material shooting off into space. This particular one was aimed at Earth and Mars. It is the space equivalent of a Category 5 hurricane.

The Solar Dynamics Observatory satellites first picked up this solar flare erupting from the sun on January 22, 2012. Almost immediately there was a large burst of radiation, higher levels than have been measured since 1989. The highly energetic ionized particles erupted from the sun as part of this CME traveled well above the speed limit - at roughly 2,200 kilometers per second - and hit Earth on January 24 around 10am US Eastern Time.

Why would you possibly care?

Because there are some amazing side effects from one of these events that can directly affect you.

The huge ion bomb, when it strikes Earth's protective magnetic field, is partially deflected towards the poles. Auroras sometimes reach the mid-continental United States during these events. They set up huge telluric currents in the Earth's surface - these are short-circuited by the oceans, but the shallow continental crust is resistive to varying degrees. Basic physics says that if current is flowing, there must be a voltage difference causing it. Electrical power grids generally transmit electrical energy at very high voltages (in the 100,000 range and higher) in three "phases" - in other words, the power on each of the three lines held up by transmission towers is at 60 Hz (in North America; 50 Hz in Europe and the British Commonwealth), and each line's alternating signal is out of phase from the other two by 120 degrees. Think of a wheel turning through 360 degrees for each cycle, then each cycle will peak at 4 o'clock, 8 o'clock, and 12 o'clock in sequence.

But the power transmission system is never perfectly insulated - electrical charge inevitably "leaks", and for this reason each tower and power substation has a fourth electrical line called a "ground" to take care of that leakage. This is the fat round opening on the bottom of most electrical sockets. In our homes, we only "see" two phases and a ground after the voltage is stepped down by transformers to 220 volts and 110 volts. The assumption underlying all grounds is that the Earth is all at the same base voltage - the same reference point. However, if there is a large telluric current (this word means an electrical current flowing through the ground), then the voltage of each tower's "ground" and each substation's "ground" is going to be different. Inevitably something will become unstable - a ground-loop is set up - and an excessive voltage at some point is going to lead to an "arcing" or jump of current to someplace where it shouldn't be going. It's not unusual for transformers the size of a car or an SUV to explode violently when this happens. This is commonly seen in video of a city skyline as a tornado approaches: the transformers "pop" with a flash, one by one.

How could this affect you? The Canadian provinces of Quebec and Ontario experienced a huge and long-lasting blackout due to a CME event back in 1989. In mid-winter, if electricity is your source of heat, this could be a life-threatening event. If you survive, your water pipes will freeze and burst, and you will have heck to pay when it warms up again.

What else happens? The huge telluric currents overwhelm the carefully-designed electrical corrosion protection on oil and gas pipelines. Most readers are aware of the fiery inferno that happened in San Bruno, California two years ago when a corroding pipeline leaked natural gas that somehow ignited. Whole neighborhoods were consumed in a raging fire that took hours to subdue.

Death by fire, death by flood.

Do you use GPS in your car? You can expect that the GPS satellites, which are designed to withstand this sort of event up to a point, might malfunction. Some satellites can go off-line for awhile or even permanently if the damage is too severe. I hope you are aware that any commercial airliner you fly in depends on GPS. Same holds for weather and communication satellites. American Idol? You may miss an episode, but that may not necessarily be a bad thing...

Death by boredom. Are you starting to feel a pinch now?

Large and turbulent changes in the ionosphere during geomagnetic storms triggered by these CME events interfere with high-frequency radio communications... just what your pilot is using to communicate with the control tower. As of today (24 January) Delta Airlines has started re-routing pole-crossing international flights away from the poles, where the dipolar nature of the Earth's magnetic field allows these huge ion-storms to penetrate deeply into our Earth's protective atmosphere. This is why the auroras will be so bright and far-reaching tonight.

What about our astronauts in the International Space Station? They have a protective "safe room" to retreat to, but this is a partial mitigation at best. As I write this, all six astronauts in the ISS are being severely irradiated. The highly energetic particles during solar events like this cause temporary operational anomalies, damage critical electronics, degrade solar arrays, and blind optical systems such as imagers and star trackers. The latter are necessary to keep the solar arrays correctly oriented, and to keep one side of the ISS from broiling while the other side freezes.

For the vast majority of us, there will likely be no manifestation of anything unusual. But then, when Hurricanes Andrew (1992), Isabel (2003), Katrina (2005) and Felix (2007) struck the eastern United States, most of the rest of us felt nothing... until the forced immigrants began to arrive.


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