The NASA Space Weather Laboratory reported that a massive Coronal Mass Ejection (CME) struck the Earth’s magnetic field at approximately 2PM EST on October 24th, 2011. The CME (solar storm) caused a geomagnetic storm that lit up the sky with dramatic Northern Lights (aurora borealis). Observers have reported vivid auroras as far south as Alabama and Georgia.
Scientists measure the intensity of solar storms using the kP index. Anything above a 5 on the kP index and auroras and other terrestrial effects are expected. The Oct 24th storm registered a very strong 7 at its peak. A very strong solar event!
Why should the data center community care? Two reasons:
- Geomagnetic storms can affect the reliability of utility power.
- Geomagnetic storms can affect the reliability of satellite and terrestrial communication systems
When a CME strikes the Earth’s magnetic field it compresses and distorts the field. This compression can expose high altitude (22,233 miles) geostationary satellites to solar wind plasma and intense radiation. This type of exposure can easily and quickly fry sensitive electronic equipment aboard satellites. Satellites in high altitude geostationary orbits include communication satellites. (Data, TV, Image and some telephone transmissions) The loss of one of these satellites could affect day to day operations in some data centers. In addition, disaster recovery plans may be impacted by compromised communications.
Additionally, increased solar radiation causes the atmosphere to swell. Low Earth orbit (LEO) satellites that are typically above the Earth’s atmosphere may be exposed to additional drag by the puffed up atmosphere. It was drag and slowing caused by unexpected atmospheric drag that caused the early death of the 70’s era satellite known as SkyLab. LEO satellites are typically used as observation platforms and are responsible Earth imaging. However, in some cases emergency radio communications are handled by LEO satellites.
Technology systems on the Earth’s surface can also be adversely affected by geomagnetic storms. The distortion of the magnetic field that exposes satellites to the solar wind also causes the magnetic lines of flux that penetrate the Earth’s surface to shift around. When a moving magnetic field crosses a really long conductor it will induce a current in that conductor. These induced currents are called Geomagnetically Induced Current (GIC). GICs can be induced in man-made technology infrastructure such as telephone lines, railways, pipelines and the national electrical grids.
The national electrical grids are usually already carrying as much current as they can safely handle. When a geomagnetic storm adds GIC on top of that current, grid components like transformers and breakers suffer accelerated component breakdown and can experience catastrophic failure.
The destructive potential of a large scale GIC event was demonstrated in 1859 and is known as The Carrington Event. In the Carrington Event, a massive solar storm struck the Earth’s magnetic field. Auroras were seen as far south as Havana, Cuba. The only significantly long conductors at the time were the copper lines that had recently been strung up for a new technology known as “the telegraph”. When the solar storm struck, telegraph stations around the country burst into flame. For days after the event, telegraph operators were able to disconnect the batteries from their systems and operate off of “celestial power”. Experts warn that a Carrington scale event today could result in widespread power failures that last for weeks or months. Damage estimates for such an event are measured in trillions of dollars and tens of thousands of lives.
A detailed report of the economic impact of a Carrington type event was prepared by the National Academies Press for NASA in 2010. That study is available here.
Data centers and operators of other mission critical infrastructure should be aware that the sun is entering a phase of increased activity. Activity is expected to increase until it peaks with the solar maximum in 2013. As a result, solar storms such as the October 24, 2011 event will be more common. Let’s all hope that none of these events are as intense as the Carrington Event.