Affects of Solar Storms on Earth

A Roman garrison in 34 AD was mistakingly ordered to march to the coastal town of Ostia because Tiberius Caesar thought that the red glow seen on the northern horizon at night was Ostia in flames (Aurora forecasts). In China two thousand years earlier, the 'Yellow Emperor' was conceived during an auroral display. Up until very recently, this was about all you could find to indicate that there were genuine 'other-worldly' influences upon us instigated by the rather passive sightings of sunspots or aurora. Even today, the average person is unaware of either sunspots or aurora since neither are easily observable.

In just one generation, our reliance upon uninterrupted power supplies to run our computer-rich, Internet-laced, civilisation; our colonisation of near-earth space with hundreds of billions of dollars of satellites and manned human missions, has placed all of these enterprises at great risk of damage by solar storms. Like new settlers to Kansas discovering tornadoes for the first time, we now have to reach a grudging accommodation with aurora and their invisible confederates that ply the ether above our heads. Unlike these settlers however, we have to be frequently reminded that there is a problem at all. Fortunately, many examples of what this solar mayhem can do are easy to come by.

Beginning with the invention of telegraphy in 1841 and the telephone in the 1870's, vast systems of telephone and telegraph lines were strung-up across many of the continents. It didn't take very long before these new modes of communication began to turn up, not just an occasional long-distance call from Uncle Bill but some entirely unintended messages from Mr. Sun. During solar storms 'earth currents' induced by the changing terrestrial magnetic field were so powerful that telegraphers didn't need a battery to send their messages down the line. Some were even treated to near-electrocution!

William Ellis of the Royal Greenwich Observatory provided the first solar storm forecast in 1879 informing the telegraphic community that sunspots are correlated with periods of strong auroral activity. He noted that in the most recent years, there was little magnetic activity, and that telegraphic technology had taken a turn towards even more sensitive apparatus and cross-continental cables. He worried that with the next solar maximum only a few short years away, the new technology would be even more susceptible to magnetic 'storm' damage. No one took him seriously.

As solar storm particles arrive at the Earth and enter the magnetosphere, they temporarily set-up an invisible, circulating flow of charged particles around polar regions of the earth: The Ring Current. This current causes magnetic field fluctuations near the ground which in turn induce currents to flow in wires - especially long telegraph lines! But it doesn't even matter if these wires are under the ocean because electro

magnetic energy can pass through water with little hindrance. In the Atlantic Cable between Scotland and NewFoundland, voltages up to 2 600 volts were recorded during the March 1940 magnetic storm. A February 9/10 1958 storm caused severe interruptions of telephone service on Western Union's North Atlantic telegraph cables, and disrupted phone calls carried by the Bell System's coaxial cable link between NewFoundland and Scotland.

25 January 2001 - The first large-scale pictures of the hidden machinations of the Earth's magnetic force-field became available, including confirmation of a suspected but previously invisible 'tail' of electrified gas. The tail, which streams from Earth towards the Sun, was spotted by NASA's Imager for Magnetopause to Aurora Global Exploration (IMAGE) spacecraft. It's featured on the cover of the 26 January issue of the journal Science. IMAGE (launched 25 March 2000) is offering researchers an unprecedented view of the transparent, electrified gas trapped within Earth's magnetic field, providing the first visual, global perspective on magnetic storms (right)

The 24 March 24 1940 storm caused a temporary disruption of electrical service in New England, New York, Pennsylvania, Minnesota, Quebec and Ontario. A storm on 9/10 February 1958 caused a power transformer failure at the British Columbia Hydro and Power Authority. On 2 August 1972, the Bureau of Reclamation power station in Watertown, South Dakota was subjected to large swings in power line voltages up to 25 000 volts. Similar voltage swings were reported by Wisconsin Power and Light, Madison Gas and Electric, and Wisconsin Public Service Corporation. A 230,000-volt transformer at the British Columbia Hydro and Power Authority exploded, and Manitoba Hydro in Canada recorded power drops in the power it was supplying to Minnesota from 164 to 44 megawatts in a matter of a few minutes.

Perhaps the most dramatic, recent impact occurred in March 1989 during the peak of the last sunspot cycle, when the sun produced one of the most powerful storms ever recorded. On 13 March 1989 Alaskan and Scandinavian observers were treated to a spectacular auroral display. In fact, this display was seen as far south as the Mediterranean and Japan. Although many millions of people marvelled at this beautiful spectacle, many millions more were not so happy about it. Hydro-Quebec on Saint James Bay did the best it could to stabilise the power surges its lines received but ultimately failed the challenge. For 9 hours, large portions of Quebec were plunged into darkness.

According to John Kappenman, CEO of Transmission Power Engineering at Minnesota Power and Electric, the frequency of transformer failures is higher in geographic regions where magnetic storms are also more common such as the north-eastern US region which had 60% more transformer failures. Moreover, the number of failures follow a solar activity pattern of roughly 11 years. A conservative estimate of the damage done by geomagnetic storms to transformers by Minnesota Power and Electric was $100 million. Oak Ridge National Laboratories estimated that the collateral impact to the economy of another March 1989 storm of only slightly greater severity would produce a Northeast United States blackout, and cause $6 billion in damage. The North American Electric Reliability Council placed the March 1989 and October 1991 storm events in a category equivalent to Hurricane Hugo or the San Francisco earthquake in their impact upon the national economy (see AGU Report on transformers and solar storm effects)

Just as good for generating large induced currents as telegraph and power lines are long, uninterrupted segments of oil and natural gas pipelines. Currents flowing in pipelines are known to enhance the rate of corrosion over time, and this can have catastrophic effects. On 4 June 1989 a powerful gas pipeline explosion demolished part of the Trans-Siberian Railroad engulfing two passenger trains in flames. Rescue workers at the Ural Mountain site worked frantically to rescue passengers. Of the 1200, all but 500 could be saved. Many of the victims were children bound for holiday camps by the Black Sea. Apparently gas from a leak in the pipe line was ignited by the two passing trains. The gas settled into the valley that the trains were passing through at the time. Rumours of sabotage were widespread among the local population, but no one suspected the aurora and the invisible corrosive currents it spawned over time. The Alaskan oil pipeline is a newer technology and is specifically designed to minimise these geomagnetic currents, but the Siberian pipeline was an older technology without these safeguards in place (Summaries of newspaper reports in this catastrophe can be found at Image/Poetry's Space News page)

You would think that all this catastrophe would surely be picked up by major newspapers, but you would be quite wrong. The Chicago Tribune, The Washington Post and the London Times were curiously silent about the March 1989 blackout. Only the Toronto Star on 13 March 1989 reported that "Huge Storms on Sun linked to blackout that crippled Quebec" The problem is that many of these calamitous events are at the nuisance level, and they are seemingly unrelated. No grand conspiracy is afoot, and only small, geographically remote segments of humanity seem to be affected. But now times have definitely changed as we enter the Satellite Era with hundreds of millions of subscribers relying on the flawless and reliable working of satellite technology.

There is a long list of satellites that have been confirmed to have been directly affected by solar storms and the enhanced particle fluxes the satellites intercept. It is also this category of impacts that seems to contain the greatest controversies among satellite designers, insurance companies and scientists working behind the scenes (see J-Track for a 3-D orbit simulator for all major satellites)

The visible and infrared spin-scan radiometer of satellite GOES-4 (26 November 1982)was disabled for 45 minutes after the arrival of high-energy protons from a solar flare. Marecs-B, a marine navigational satellite, was disabled by the strong electrical currents flowing during a week of intense auroral activity in February 1982. GOES-7 weather satellite lost half of its solar cells during a large proton release by the sun during the powerful 13 March 1989 storm which cut the operating life span of this satellite in half. Two Canadian communications satellites - ANIK E-1 and E-2 were disabled on 20/21 January 1994 due to the elevated activity of high-energy electrons in the magnetosphere. A similar disturbance in August 1993 was implicated in causing temporary pointing errors in five Intelsat satellites. The Intelsat-K satellite (source) began to wobble a few hours before the 20 January 1994 event which affected the Anik E1 and E2 satellites. Intelsat-K also experienced a short outage of service during this time. On 11 January 111997 at 06:15 EST, AT&T experienced a massive power failure in its Telstar 401 satellite. A few hours before Telstar 401 began to show signs of malfunctioning, the GOES-8 weather satellite experienced its own difficulties. Meanwhile the plasma from a solar storm had just arrived hours before (see: National Academy of Sciences' Report on the practical consequences of Space Weather and satellite impacts)

It is important to realise that simultaneous events need not be correlated. The SOHO satellite recently showed two comets plunging into the sun, and hours later the sun disgorged a massive cloud of plasma. These are 'simultaneous' events but not connected by cause and effect. Also, if there are thousands of working satellites in space, why is it that a specific storm only seems to affect a few of them, if any at all? Despite the dramatic consequences for Telstar 401, no military satellites were apparently affected by this particular storm, and Hughes Space and Communications which manufactured over 40% of the commercial satellites now in orbit, had neither received any reports of any anomalies related to the storm among other satellites of similar type. If solar storms are so potent, why don't they take out several satellites at a time? Solar storms are at least as complex as tornadoes, and we know that tornadoes can flatten one house while leaving its neighbour's untouched, but that doesn't persuade us to deny the existence of tornado damage. We can see tornadoes coming with our own eyes. Not so for solar storms: The ultimate Stealth Bombers of the solar system.

During the last few years it has become popular to blame any odd event on El Nino from a 'bad hair day' to droughts in Texas. Literally billions of dollars of commercial satellite insurance money rides on whether a satellite failure was an 'Act of God' (uninsurable) or a subtle satellite design flaw (insurable). A scientist's guarded opinion cannot be submitted as evidence to support one side or the other of an insurance claim. There must be a rigorous and precise statement in the court of law that 'Event A caused Satellite B to fail, but did not affect at the same time Satellites C, D, E ....Z'. Usually, this kind of guarantee cannot be provided scientifically because the satellite is unrecoverable, and only apparent correlations in time and space can be offered as evidence that a specific solar event affected a satellite in a specific way, leaving its neighbour's unaffected. This often allows commercial satellite companies to claim that no natural 'Act of God' event was indisputably involved. Sometimes, after all, satellites do simply malfunction in orbit after many years of operation.

It was widely reported in the media such as Aviation Week and Space Technology, that a solar storm had damage the Telstar 401 satellite, but some scientists were not so ready to implicate the solar storm as the proximate cause of the damage to the satellite. Robert Hoffman, a NASA scientist and PI for the POLAR satellite, was quoted in Aviation Week and Space Technology as saying that, although the satellite was located in an affected area of the magnetosphere: "We have no idea what caused the failure". Physicist Geoff Reeves at Los Alamos National Laboratory also supported this cautious position: "We know that these conditions can cause problems for satellites, but unless we can go up with the space shuttle, bring the thing back, and look at it in the lab, we'll never know exactly how it failed" (See: "Faulty Materials Blamed in Failure of Telstar 401", Space News, May 26, 1997)

Scientists do however, know a thing or two about how radiation affects satellites, at least in the case of research satellites which represent a very non-threatening population. When research satellites fail, scientists do not get paid satellite insurance dividends, nor are there national security issues involved. Instead, some scientists may quietly lose their careers, and taxpayer money is silently lost in the accounting book work.

The most destructive ingredient of solar storm activity for satellites seems to be in the high-energy electrons rather than the other types particles. These electrons do their damage by producing 'deep dielectric charging' in unprotected parts of the satellite. Data taken by the SAMPEX satellite of the energetic electrons near geosynchronous orbit, against the times when the Anik satellites were affected, show that the failures happened near the peaks of this activity. Data provided by Rice University and NOAA and NGDC scientists show that satellite surface charging 'anomalies' detected by the GOES-4 and GOES-5 spacecraft in geosynchronous orbit, correlate very well against a period when electrons were injected into this orbit due to the passage of a disturbance from the geotail region into the inner magnetic field regions around the earth. Some satellite designs, or satellite orbital locations, seem to have a higher risk for solar storm affects than others.

One recent, and spectacular, satellite outage occurred on 17 May 17 1998 when the PanAmSat's Galaxy IV satellite, insured for $165 million, lost control, and shut down service for millions of pagers in North America. Hughes' investigators believe this was due to a rare buildup of crystals in a switch designed to control the flow of electricity to satellite processors. Hughes' vice president Jeff Grant is quoted as saying that Hughes officials do not feel that the processors on the other 30 satellites of similar model type (HS-601s) are likely to fail but that: "We feel we could have another processor failure on a spacecraft in orbit. I don't think we would be immensely surprised" (Space News, 13 July 1998)

Was there a solar storm or other geomagnetic storm in progress at that time? Between 27 April and 6 May NASA satellites detected 7 CMEs and two very powerful solar flares which temporarily produced a new radiation belt orbiting the Earth. Several magnetic storms were recorded on earth on 2 May and 4 May causing New England power companies to reduce their power-sharing capacity with Canada as a precaution. On 2 May, the Equator-S satellite failed, but the connection between the solar storms and the satellite failure was hotly in dispute. The 6 May storm affected the POLAR satellite which had to be shut down for several hours to recover. According to plots made of the high-energy electron fluxes near the Earth by Geoff Reeves (Los Alamos Laboratories), the period from 15-19 May recorded the maximum electron fluxes during this storm period. So, did Galaxy 4 fail because of the high-energy electron environment or because of faulty switch design? This is the core of the regular controversy over the failure of commercial satellites.

Of particular concern are the so-called 'phantom switches' where data bits are switched from '1' to '0' or vice-versa because of a discharge in the electrical device caused by a high-energy particle strike. A nearly perfect correlation can be found between specific bit-switches and energetic electron enhancements detected by the GOES-7 and METEOSAT-3 satellites. The switches seemed to happen most often during periods when the electron impacts remained high for several days at a time. It isn't a single intense storm that seems to do the dirty work, but a sustained period of high electron 'storm' activity near the spacecraft. Even commercially available hand calculators on-board the MIR have been used to track bit switches (see: Space Environment Effects at the NASA, Marshall Space Flight Center)

Solar activity doesn't have to take a direct swipe at a satellite to do it harm by throwing high-energy particles at it. There is an old Irish saying "May the road rise up to meet you". For satellites during heightened solar activity, the earth's atmosphere can puff up like a balloon and offer increased atmospheric friction. The premature demise of such satellites as the Solar Maximum Mission (SMM April 1990) and Skylab(July 1979) is the result. During the March 1989 storm, US Space Command had to post the new orbital elements for over 1000 objects whose orbits had been affected by the momentarily increased air resistance hundreds of miles above the earth's surface.

Between 1997 and 2007 it is estimated that as many as 1000 new satellites will be launched - 75% for commercial use. Most will be located in nearly a dozen satellite networks located in low earth orbit (LEO) between 200 and 800 km. Among the heavily used satellites already in place are the Motorola Iridium network of 66 satellites in LEO, the Intelsat network of 25 satellites in geosynchronous earth orbit (GEO) near 34 000 km, and the Global Positioning System with its 24 satellites at 18 000 km costing $10 billion. 'Individual Investor' magazine (June 1998) announced on its cover 'The Sky's the Limit: In the 21st century satellites will connect the globe'. The International Telecommunications Union in Geneva has predicted that between 1996 and 2005, the demand for voice and data transmission services will increase from $700 billion to $1.2 trillion, and that the proportion carried by satellite services will reach a staggering $80 billion. To meet this demand, many commercial companies are launching aggressive networks of LEO satellites. But there is more than satellite technology riding on the line for the next solar maximum.

Most people have an instinctive fear of radiation and its potential biological effects. No matter where you live, you receive a free dose each day of environmental radiation which adds up to 360 millirems (4 or 5 chest X-rays) per year, and you have no control over this. Cancer risks are generally related to radiation exposure, and one obtains between 12 and 100 cancers per 100,000 people for every 1000 millirems of additional dosage per year. This has been translated into 'acceptable' risks and dosage levels for different categories of individuals and occupations. Some careers are worse than others for producing large lifetime dosages such as, nuclear plant operators and astronauts.

During the Apollo programme, there were several near-misses between the astronauts walking on the surface of the Moon and deadly solar storm events. The Apollo 12 astronauts walked on the Moon only a few short weeks after a major solar proton flare would have bathed them in a 100 rem blast of radiation. Another major flare that occurred half way between the Apollo 16 and Apollo 17 moonwalks would have had a much more deadly outcome had it arrived while astronauts were outside their spacecraft playing golf. Within a few minutes, the astronauts would have been killed on the spot with an incredible 7000 rem blast of radiation (see also)

The MIR space station was inhabited for over a decade, and according to Astronaut Shanon Lucid (Scientific American, May 1998), the daily dosage of radiation was equal to about 8 chest X-rays per day. During one solar storm towards the end of 1989, MIR cosmonauts accumulated in a few hours, a full-year's dosage limit of radiation. Meanwhile, the International Space Station (ISS) will be assembled in an orbit which will take it through the South Atlantic Anomaly. Moreover, ISS assembly will involve several thousand hours of space walks by astronauts. The main construction work will occur between the years 2000 and 2002 during the sunspot maximum period of Cycle 23. We can expect construction activity to be tied to solar conditions in a way that will frustrate the scheduling of many complex activities and the launches of ISS components.

The next solar cycle is already upon us, and if the blackouts, communication outages and satellite problems of the last few cycles are any indication, we could be in for some interesting news headlines, or interesting denials of cause and effect. Increasingly more people are becoming sensitised to the need for paying attention to solar storm effects upon satellite operability. For instance, in Satellite News (1 June1998 p.3) an essay notes that: "...The sun is nearing the peak of its 11-year activity cycle, signaling an increase in solar flares. This may lead to waves of radiation and high energy protons bombarding the planets throughout the coming months and years, rendering billions of dollars of satellite constellations vulnerable to extreme conditions." (see also Space Weather Today)

Shielding is dead weight, but it costs just as much as million-dollar technology to put into space. So, satellites are designed with the minimum shielding that the engineers think that they can get away with to keep the satellite functioning without breaking the bank. There is nothing wrong with this strategy, provided you are willing to take the gamble that you can anticipate accurately what the typical environment will be like during the satellite's lifetime. If you guess wrong, the shielding is inadequate and your satellite is lost. As pointed out by William B. Scott in Aviation Week and Space Technology magazine: "Austere defense budgets also have increased reliance on more affordable, but perhaps less robust, commercial off-the-shelf hardware...expensive radiation-hardened processors are less likely to be put on some military satellites or communication systems now, than was once the case according to USAF officers...newer chips are much more vulnerable than devices of 10-15 years ago"

From the first day of the Space Age, engineers recognised that the geiger counters inside scientific research satellites such as Vanguard and Explorer were madly ticking away the cosmic ray traffic even from inside the skin of the satellite. There are many well-known elements to this problem that are by no means a mystery to satellite designers. In the mid-1960s, NASA became a leader in developing and refining models of the Earth's environment through the Trapped Radiation Environment Modeling Program (TREMP). The most recent of these models for the high-energy electrons and protons are called AE-8 and AP-8 models. Because they are strictly statistical averages over time and space, these 30-year- old models do not include solar storm events which can produce a year's worth of radiation damage in a few hours. Despite the incompleteness of the AE and AP-8 models, they are in widespread use today. NASA has now begun to invest millions of dollars in research satellites and newer generations of models that will be substantially more accurate. They will for instance, not average many different data together, but will follow the detailed changes in many different data sets across time, space and energy. As 'physics-based' models, they will take advantage of more than 30 years of advances in plasma physics theory to improve upon their predictability. But the new models are not ready yet, and so satellite designers rely on older models to calculate spacecraft shielding.

In an age where the philosophy 'cheaper, faster and smaller' drives many satellite designs, satellites have become more susceptible to solar storm damage than their less sophisticated predecessors. Amazingly, as more satellites become disabled by 'mysterious' events, we are having to rediscover the importance of old lessons in satellite design and the costs are passed on to us as the end users.

Meanwhile, the next time you hear about power outages or satellite failures in the next few years, don't blame 'El Nino', instead you might also consider blaming ol' Mr. Sun. After all, he's been up to his same old tricks for millennia. With effort we could find ourselves a bit more prepared for his mischief!