27 February 2014
When I think of weather, I think of sunshine and rain, hot and cold, wind and calm. And, when I think about weather, I always think about the earth’s atmosphere. I really never wake up in the morning worrying about what the weather is going to like – in space.
“Space weather” always seems like an odd term because there is nothing like the earth’s atmosphere in space. Actually, there’s nothing in space. Hence, the term “space.” But actually, there is “something” in space, and that “something” is energy.
The term “space weather” also seems odd because the source of all space weather is the sun. So, why not call it “solar weather?” Well, the sun throws out so much energy that it affects all the “space” in the rest of the solar system. So, the earth’s “energy weather” (or geomagnetic weather), is produced by the energy constantly thrown off by the sun.
But let’s begin at the beginning.
The sun constantly gives off energy, which flows in all directions. That flow is called the solar wind. And, in turn, the solar wind affects the earth. The earth has its own energy field including the magnetic poles (which make compass needles point to the north). As the “solar “wind” hits the earth’s own magnetic field, it produces visible auroras at both the North and South Poles. The aurora to the North is called “the Northern Lights.”
The sun also has storms when the constant rush of solar wind is interrupted by explosions of energy from the surface of the sun. Space weather’s version of lightning, solar flares, burst out of the sun in all directions. Few strike the earth because the earth is a small target. But, occasionally, the earth takes a hit.
If you’re an astronaut in space, solar flares are really bad news because they are fatal to humans without the protection of the earth’s atmosphere. Modern spacecraft can, but don’t necessarily, provide complete protection. How did our early astronauts get by? Very careful timing. Most of us pay little attention to the “space weather” forecasts. Fortunately for our early astronauts, NASA has always paid a great deal of attention and timed its manned missions very carefully.
Our atmosphere protects us from the negative effects of solar flares – even the worst solar flares: CME’s. Coronal Mass Ejections (CME’s) are the worst that space weather has to offer. On the good side, these produce beautiful auroras — much bigger and brighter than usual. No one knew about the bad side until we started using electrical power.
CME’s supercharge the earth’s atmosphere. Electricity moves more easily through a supercharged atmosphere. If you build up a big enough charge in the atmosphere, electricity can move through it easily. Too easily.
When the atmosphere offers less resistance than the “wires” in our appliances, the electricity “bleeds” out of the wires to the place electricity is always seeking – the ground.
This may sound “interesting” until your car or truck just stops running. Well, unless your car or truck has a diesel engine. Diesels don’t depend on electricity to operate (spark plugs, etc.) Meanwhile, in your home, your electric lights would dim to a fraction of their old brightness as most of the electricity flowed out of the wires, through the air, and to the ground. More unnerving are the lights that might start glowing even though they’re turned off. Electricity, as it bleeds through the air, can pass into powered-down electrical appliances and cause them to begin to operate.
This is all pretty weird. And it’s also dangerous — if you depend on a continuous supply of electrical power. Satellites in space depend on their “wires” to carry electrical power to where it is needed. Aircraft, even if they don’t depend on electrical transmission for their basic operation, have computers that do. Hospitals and emergency response units depend, not only on lights, life-saving equipment, and electronic monitors but require the best possible performance from their communication equipment. Your telephone, both cell and landline, would be substantially impaired in a severe geomagnetic storm.
The good news is that storms severe enough to produce serious electrical disruptions don’t happen very often. In fact, researchers can determine when really serious solar storms of the past happened by examining ice cores from ancient glaciers. Without going into the mechanics, it’s enough to say that really serious solar storms happen about ever 500 years. However, some “less serious” ones can be real doozies.
A BRIEF HISTORY OF SOLAR STORMS
On January 9, 2014, a lightshow was expected from space. And “aurora watchers” followed the “space weather” forecasts. They were disappointed when the “magnitude of the impact” was “downgraded.” The CME that was predicted to strike the earth was much weaker than expected. The Northern Lights didn’t expand and weren’t visible in the 48 states of the continental United States.
An aurora was visible, but over a much more limited area. One commentator was puzzled by the problem saying, “We could see it in Norway.” And I bet they could. Even weak auroras are visible in, or near, the Arctic Circle. But it takes quite a CME, of a certain type, to treat people in the temperate zone to a good show.
So, in the lower 48, we missed the Northern Light show, but we also avoided the “minor disruptions to communications and GPS” of which NOAA’s Space Weather Prediction Center had warning days earlier.
OCTOBER 2003 – THE HALLOWEEN STORMS
On Wednesday, 22 October 2003, a “brief but intense,” geomagnetic storm was caused by what NASA described as “the fourth most powerful solar flare every seen.” The storm expanded and brightened the Northern Lights, while it also knocked out some airline communications including high-frequency voice-radio communications for aircraft flying far northern routes. British air traffic controllers favored southerly routes for trans-Atlantic jets during the period of the storm. Canadian spokesman Louis Garneau explained that, in an emergency, airliners could use VHF frequencies to communicate with other aircraft or military monitoring stations.
Although the storm was a direct threat to electric utilities, high frequency radio communications, satellite navigation systems and television broadcasts, there were few immediate reports of damage. However, NOAA Space Weather Center forecaster, Larry Combs stated, “We know that our power grids are definitely feeling the effects of this.”
The North American Electric Reliability Council of Princeton, New Jersey noted no reported failures. Crewmembers, Foale and Kaleri, of the international space station, Expedition 8, moved to the one end of the station’s service module. They spent 20 minutes there sheltered by the special radiation shielding designed to protect the pair in case of such an event.
The Japanese space agency temporarily shut down one of its satellites and lost contact with a second. U.S. and European researchers, together with commercial satellite operators, shut down some delicate equipment, including solar panels and, carefully, turned satellite sensors away from the storm’s blast.
14 JULY 2000 – THE BASTILLE DAY STORM
On July 13, 2000, NASA and NOAA were tracking a solar storm as part of a joint project with the European Space Agency. NASA was hoping to view an intense solar flare and its energetic proton shower with the observational satellite, Solar and Heliospheric Observatory (SOHO). NOAA’s was doing the same with its Geostationary Operational Environmental Satellites (GOES).
This would have been an opportunity to observe, for the first time with sophisticated satellite observatories, a rare solar and geomagnetic event. The solar flare was the guest of honor at the party. But the party had a crasher. An extremely powerful CME coincided with this particular flare.
The Advanced Composition Explorer (ACE) spacecraft was to give the first warning an hour before the arrival of the geomagnetic storm. But the wave of particles came with such strength that the ACE’s important detectors were blinded and failed. Without ACE, the observers could only time the arrival by watching for distortions in the Earth’s magnetic field. They didn’t have long to wait. The storm raged for almost nine hours.
The storm flooded cameras and star-tracking navigation devices on several satellites with solar particles compromising the devices’ operation. Particle detectors on several NOAA and NASA spacecraft failed or were shut down to avoid damage. Although these events hardly seem good, it could have been worse. The Japanese Advanced Satellite for Cosmology and Astrophysics (ASCA) was sent tumbling in orbit by the energetic wave from the sun.
On the ground, power companies struggled with geomagnetically induced currents that tripped capacitors and damaged at least one transformer. Global positioning system (GPS) accuracy degraded for several hours.
Of course, if you were an aurora watcher, you were in luck. The aurora lightshow was seen as far south as El Paso, Texas.
MARCH 1989 – THE CANADIAN GEOMAGNETIC STORM
A CME left the Sun’s surface on March 6, 1989. Three and a half days later, on March 9, intense auroras formed at the poles and could be seen as far south as Texas and Florida — these were the first signs that a severe geomagnetic storm had struck the earth.
Cold War fears of a nuclear attack were triggered when the burst caused short-wave radio interference. Disruption of radio signals from Radio Free Europe into Russia aroused suspicions that the Soviet government had jammed the signal.
By midnight, communications from a weather satellite were interrupted. Another communication satellite, TDRS-1, recorded over 250 anomalies caused by the increased particles flowing into the satellite’s own electronics. The space shuttle Discovery, on a mission at the time, experienced an unusually high reading from a pressure sensor on one of its fuel cells. The anomalous reading disappeared after the geomagnetic storm ended.
Beneath all of Quebec, Canada is a large layer of rock. This rock layer acted as shield against the natural discharge of the electricity from the highly charged atmosphere into the ground. Without another path of discharge, the powerful atmospheric electrical potential found its path of least resistance along long utility transmission lines. Circuit breakers on Hydro-Québec’s power grid were tripped, and Quebec’s James Bay network experienced a 9-hour power failure.
NOVEMBER 12, 1960 – THE MYSTERY GEOMAGNETIC STORM
An American astronomer described the solar flare that caused this storm as “one of the largest, if not the largest, ever recorded.” Communications were disrupted worldwide. The aurora, the Northern Lights, could be seen as far south as Washington D.C. Oddly, it is extremely difficult to find any information or even copies of contemporary news articles about this event.
MAY 1921 — NORTHEASTERN POWER FAILURE
A CME caused a geomagnetic storm which lasted from May 13th through the 15th in 1921. The Northeastern United States experienced a checkerboard of blackouts. The Northern Lights were bright and visible throughout the northern United States. And the timing of the show was fortunate because so many other activities came to a halt as fuses blew and telegraph equipment became so damaged that service slowed to a complete stop throughout the United States. On the other hand, radio waves were strengthened by the storm allowing intercontinental reception.
17 NOVEMBER 1882
Another geomagnetic storm caused by the arrival of a solar flare on November 17, 1882. Some telegraph systems were rendered useless. The switchboard at the Chicago Western Union offices caught fire several times and the equipment was badly damaged. In Milwaukee, an electric lamp, although “turned off,” was reported to have lit up. In the UK, telegraphs were strongly affected.
1-2 SEPTEMBER 1859 — THE CARRINGTON EVENT (THE BIG ONE)
Remember those researchers who checked the ice cores for evidence of past CME’s? They found that a really big one hits the earth causing a really big geomagnetic storm about once every 500 years.
Well, the last one of those happened in 1859.
The “Carrington Event” began when an amateur astronomer, Richard Carrington, observed the sun suddenly grow larger and brighter. He knew that the sun had never done that before. He also knew that a flare from the sun’s surface would be visible as a bright emission – sort of like watching a gun being fired. Figuratively speaking, you’d see the plume of smoke and might even have an impression of something leaving the barrel of the gun. Or, at least, you would . . . unless the barrel of the gun was aimed right at you.
What Richard Carrington couldn’t have known, at the time, was that the Sun’s size and brightness only appeared to change. A CME, in the form of a circular cloud was expanding out from the Sun. This “halo coronal mass ejection,” was so bright and emitted so much light that the sun appeared to grow in both size and brightness. Also, Carrington couldn’t have known why the “halo” cloud appeared to be almost perfectly circular. That apparent shape indicated that the CME was headed right at him.
The CME arrived about 17 hours later. Electrical equipment was relatively rare in 1859, but telegraph pylons threw sparks. Some telegraph operators were shocked by their equipment even after disconnection from a power supply. Other telegraph operators reported sending and receiving signals without external power — the equipment powered only by the electricity in the atmosphere. Magnetic instruments, as simple as a compass, wouldn’t give consistent readings.
Auroras, like the northern lights, which are seldom visible beyond the Arctic Circle, could be seen as far south as Venezuela. The Northern Lights were so bright in the Rockies that the glow was mistaken for sunrise by gold miners, who got up and started cooking breakfast.
In the northeastern U.S., people could read newspapers in the middle of the night by the light of the aurora. A writer for the Baltimore American and Commercial Advertiser waxed lyrical in his report, “The light was greater than that of the Moon at its full, but had an indescribable softness and delicacy that seemed to envelop everything upon which it rested.”
That was 155 years ago. If the averages hold, we have about another 345 years before the next “really big” event.