Geomagnetic Storms When Power Grids Collapse Contents

1 Geomagnetic storm 1 1.1 History ...... 1 1.2 Definition of a geomagnetic storm ...... 1 1.3 Historical occurrences ...... 2 1.4 Interactions with planetary processes ...... 3 1.5 Instruments for researching geomagnetic storms ...... 3 1.6 Geomagnetic storm effects ...... 3 1.6.1 Radiation hazards to humans ...... 3 1.6.2 Fauna and flora ...... 4 1.6.3 Disruption of electrical systems ...... 4 1.7 Preparations against solar storms ...... 6 1.8 See also ...... 6 1.9 References ...... 6 1.10 Further reading ...... 7 1.11 External links ...... 8

2 Solar storm of 1859 9 2.1 Carrington super ﬂare ...... 9 2.2 Similar events ...... 10 2.3 See also ...... 10 2.4 References ...... 10 2.5 Further reading ...... 11 2.6 External links ...... 12

3 March 1989 geomagnetic storm 13 3.1 Geomagnetic storm and auroras ...... 13 3.2 Quebec blackout ...... 13 3.3 Aftermath ...... 14 3.4 See also ...... 14 3.5 References ...... 14

4 Solar and Heliospheric Observatory 15 4.1 Orbit ...... 15

i ii CONTENTS

4.2 Communication with Earth ...... 15 4.3 Near loss of SOHO ...... 15 4.3.1 Additional references ...... 16 4.4 Scientiﬁc objectives ...... 16 4.5 Instruments ...... 16 4.5.1 Public availability of images ...... 17 4.5.2 Comet discovery ...... 17 4.5.3 Instrument contributors ...... 17 4.6 See also ...... 18 4.7 References ...... 18 4.8 External links ...... 18 4.9 Text and image sources, contributors, and licenses ...... 19 4.9.1 Text ...... 19 4.9.2 Images ...... 19 4.9.3 Content license ...... 20 Chapter 1

Geomagnetic storm

This article is about disturbances within Earth’s magneto- be associated with or are caused by a geomagnetic storm. sphere. For other uses of “magnetic storm”, see Magnetic These include: Solar Energetic Particle (SEP) events, storm (disambiguation). geomagnetically induced currents (GIC), ionospheric dis- A geomagnetic storm is a temporary disturbance of turbances which cause radio and radar scintillation, disruption of navigation by magnetic compass and auroral displays at much lower latitudes than normal. In 1989, a geomagnetic storm energized ground induced currents which disrupted electric power distribution throughout most of the province of Quebec[2] and caused aurorae as far south as Texas.[3]

1.1 History

In 1931, Sydney Chapman and Vincenzo C. A. Fer- Artist’s depiction of solar wind particles interacting with Earth’s raro wrote an article, A New Theory of Magnetic Storms, magnetosphere. Sizes are not to scale. that sought to explain the phenomenon of geomagnetic storms.[4] They argued that whenever the Sun emits a the Earth's magnetosphere caused by a solar wind shock solar flare it will also emit a plasma cloud, now known as wave and/or cloud of magnetic field which interacts with a coronal mass ejection. This plasma will travel at a ve- the Earth’s magnetic field. The increase in the solar wind locity such that it reaches Earth within 113 days, though pressure initially compresses the magnetosphere and the we now know this journey takes 1 to 5 days. The cloud solar wind’s magnetic field interacts with the Earth’s mag- will then compress the Earth’s magnetic field and thus in- netic field and transfers an increased energy into the mag- crease this magnetic field at the Earth’s surface.[5] netosphere. Both interactions cause an increase in move- ment of plasma through the magnetosphere (driven by increased electric fields inside the magnetosphere) and an increase in electric current in the magnetosphere and 1.2 Definition of a geomagnetic ionosphere. storm During the main phase of a geomagnetic storm, electric current in the magnetosphere creates a magnetic force A geomagnetic storm is defined[6] by changes in the which pushes out the boundary between the magneto- DST[7] (disturbance – storm time) index. The Dst index sphere and the solar wind. The disturbance in the inter- estimates the globally averaged change of the horizontal planetary medium which drives the geomagnetic storm component of the Earth’s magnetic field at the magnetic may be due to a solar coronal mass ejection (CME) or equator based on measurements from a few magnetome- a high speed stream (co-rotating interaction region or ter stations. Dst is computed once per hour and reported CIR)[1] of the solar wind originating from a region of in near-real-time.[8] During quiet times, Dst is between weak magnetic field on the Sun’s surface. The frequency +20 and −20 nano-Tesla (nT). of geomagnetic storms increases and decreases with the A geomagnetic storm has three phases:[6] an initial phase, sunspot cycle. CME driven storms are more common a main phase and a recovery phase. The initial phase is during the maximum of the solar cycle and CIR driven characterized by Dst (or its one-minute component SYM- storms are more common during the minimum of the so- H) increasing by 20 to 50 nT in tens of minutes. The lar cycle. initial phase is also referred to as a storm sudden com- There are several space weather phenomena which tend to mencement (SSC). However, not all geomagnetic storms

1 2 CHAPTER 1. GEOMAGNETIC STORM

have an initial phase and not all sudden increases in Dst or SYM-H are followed by a geomagnetic storm. The main phase of a geomagnetic storm is defined by Dst de- creasing to less than −50 nT. The selection of −50 nT to define a storm is somewhat arbitrary. The minimum value during a storm will be between −50 and approximately −600 nT. The duration of the main phase is typ- ically between 2 and 8 hours. The recovery phase is the period when Dst changes from its minimum value to its quiet time value. The period of the recovery phase may be as short as 8 hours or as long as 7 days. The size of a geomagnetic storm is classified as moderate (−50 nT > minimum of Dst < −100 nT), intense (−100 nT > minimum Dst < −250 nT) or super-storm (minimum of Dst > −250 nT). GOES-7 monitors the space weather conditions during the Great Geomagnetic storm of March 1989, the Moscow neutron monitor recorded the passage of a CME as a drop in levels known as a [12] 1.3 Historical occurrences Forbush decrease.

The first observation of the effects of a geomagnetic storm occurred early in the 19th century: From May 1806 The geomagnetic storm causing this event was itself the until June 1807 the German Alexander von Humboldt result of a coronal mass ejection, ejected from the Sun on recorded the bearing of a magnetic compass in Berlin. March 9, 1989.[14] The minimum of Dst was −589 nT. On 21 December 1806 he noticed that his compass had become erratic during a bright auroral event.[9] On July 14, 2000, an X5 class flare erupted on the Sun (known as the Bastille Day event) and a coronal mass On September 1 – 2, 1859, the largest recorded geomag- ejection was launched directly at the Earth. A geomagnetic storm occurred. From August 28 until September netic super storm occurred on July 15–17; the minimum 2, 1859, numerous sunspots and solar flares were ob- of the Dst index was – 301 nT. Despite the strength of served on the Sun, the largest flare occurring on Septem- the geomagnetic storm, no electrical power distribution ber 1. This is referred to as the Solar storm of 1859 or failures were reported.[15] The Bastille Day event was ob- the Carrington Event. It can be assumed that a massive served by Voyager 1 and Voyager 2,[16] thus it is the far- coronal mass ejection (CME), associated with the flare, thest out in the Solar System that a solar storm has been was launched from the Sun and reached the Earth within observed. eighteen hours — a trip that normally takes three to four days. The horizontal intensity of geomagnetic field was Seventeen major flares erupted on the Sun between 19 reduced by 1600 nT as recorded by the Colaba Obser- October and 5 November 2003, including perhaps the vatory. It is estimated that Dst would have been ap- most intense flare ever measured on the GOES XRS sen- proximately −1760 nT.[10] Telegraph wires in both the sor – a huge X28 flare,[17] resulting in an extreme ra- United States and Europe experienced induced emf, in dio blackout, on 4 November. These flares were as- some cases even shocking telegraph operators and caus- sociated with CME events which impacted the Earth. ing fires. Aurorae were seen as far south as Hawaii, Mex- The CMEs caused three geomagnetic storms between ico, Cuba, and Italy — phenomena that are usually only Oct 29 and November 2 during which the second and seen near the poles. Ice cores show evidence that events third storms were initiated before the previous storm pe- of similar intensity recur at an average rate of approxi- riod had fully recovered. The minimum Dst values were mately once per 500 years. −151, −353 and −383 nT. Another storm in this event period occurred on November 4 – 5 with a minimum Dst Since 1859, less severe storms have occurred, notably the of −69.nT. The last geomagnetic storm was weaker than aurora of November 17, 1882 and the May 1921 geomag- the preceding storms because the active region on the Sun netic storm, both with disruption of telegraph service and had rotated beyond the meridian where the central por- initiation of fires, and 1960, when widespread radio dis- [11] tion CME created during the flare event passed to the side ruption was reported. of the Earth. The whole sequence of events is known The March 1989 geomagnetic storm caused the collapse as the Halloween Solar Storm.[18] The Wide Area Aug- of the Hydro-Québec power grid in a matter of seconds mentation System (WAAS) operated by the Federal Avia- as equipment protection relays tripped in a cascading se- tion Administration (FAA) was offline for approximately quence of events.[2][13] Six million people were left with- 30 hours due to the storm.[19] The Japanese ADEOS-2 out power for nine hours, with significant economic loss. satellite was severely damaged and the operation of many The storm even caused aurorae as far south as Texas.[3] other satellites were interrupted due to the storm.[20] 1.6. GEOMAGNETIC STORM EFFECTS 3

1.4 Interactions with planetary • Radio sounders from the ground can bounce radio processes waves of varying frequency oﬀ the ionosphere, and by timing their return get the proﬁle of electron density in the ionosphere — up to its peak, past which radio waves no longer return. Radio sounders in low Earth orbit aboard the Canadian Alouette 1 (1962) Bow Shock and Alouette 2 (1965), beamed radio waves earth-

Reconnection ward and observed the electron density proﬁle of the “topside ionosphere.” Other radio sounding methods Solar wind were also tried in the ionosphere (e.g. on IMAGE). Reconnection

Magnetopause • A great variety of “particle detectors” have operated Magnetotail in orbit. The original observations of the Van Allen radiation belt used a Geiger counter, a crude detec- tor unable to tell particle charge or energy. Later Magnetosphere in the near-Earth space environment. scintillator detectors were used, and still later “chan- neltron” electron multipliers have found particularly The solar wind also carries with it the magnetic field of wide use. To derive charge and mass composition, the Sun. This field will have either a North or South orien- as well as energies, a variety of mass spectrograph tation. If the solar wind has energetic bursts, contracting designs were used. For energies up to about 50 and expanding the magnetosphere, or if the solar wind keV (which constitute most of the magnetospheric takes a southward polarization, geomagnetic storms can plasma) time-of-flight spectrometers (e.g. “top-hat” be expected. The southward field causes magnetic recon- design) are widely used. nection of the dayside magnetopause, rapidly injecting magnetic and particle energy into the Earth’s magneto- Computers have made it possible to bring together sphere. decades of isolated magnetic observations and extract average patterns of electrical currents and average responses During a geomagnetic storm, the ionosphere’s F2 layer to interplanetary variations. They also run simulations will become unstable, fragment, and may even disappear. of the global magnetosphere and its responses, by solv- In the northern and southern pole regions of the Earth, ing the equations of magnetohydrodynamics (MHD) on auroras will be observable in the sky. a numerical grid. Appropriate extensions must be added to cover the inner magnetosphere, where magnetic drifts and ionospheric conduction also need to be taken into ac- 1.5 Instruments for researching count. So far the results are difficult to interpret, and cer- tain assumptions are still needed to cover small-scale phe- geomagnetic storms nomena.

Magnetometers monitor the auroral zone as well as the equatorial region. Two types of radar — coherent scatter 1.6 Geomagnetic storm effects and incoherent scatter — are used to probe the auroral ionosphere. By bouncing signals off ionospheric irreg- ularities, which move with the field lines, one can trace 1.6.1 Radiation hazards to humans their motion and infer magnetospheric convection. Intense solar flares release very-high-energy particles that Spacecraft instruments include: can cause radiation poisoning to humans (and mammals in general) in the same way as low-energy radiation from • Magnetometers, usually of the flux gate type. Usu- nuclear blasts. ally these are at the end of booms, to keep them away Earth’s atmosphere and magnetosphere allow adequate from magnetic interference by the spacecraft and its protection at ground level, but astronauts in space are sub- electric circuits.[21] ject to potentially lethal doses of radiation. The penetra- tion of high-energy particles into living cells can cause • Electric sensors at the ends of opposing booms are chromosome damage, cancer, and a host of other health used to measure potential differences between sep- problems. Large doses can be fatal immediately. arated points, to derive electric field associated with Solar protons with energies greater than 30 MeV are par- convection. The method works best at high plasma ticularly hazardous. In October 1989, the Sun produced densities in low Earth orbit; far from Earth long enough energetic particles that, if an astronaut were to booms are needed, to avoid shielding-out of electric have been standing on the Moon at the time, wearing only forces. a space suit and caught out in the brunt of the storm, they 4 CHAPTER 1. GEOMAGNETIC STORM

would probably have died; the expected dose would be The Federal Aviation Administration routinely receives about 7000 rem. Note that astronauts who had time to alerts of solar radio bursts so that they can recognize gain safety in a shelter beneath moon soil would have ab- communication problems and avoid unnecessary mainte- sorbed only slight amounts of radiation. nance. When an aircraft and a ground station are aligned Solar proton events can also produce elevated radiation with the Sun, jamming of air-control radio frequencies aboard aircraft flying at high altitudes. Although these can occur. This can also happen when an Earth station, a risks are small, monitoring of solar proton events by satel- satellite, and the Sun are in alignment. In order to prevent lite instrumentation allows the occasional exposure to be unnecessary maintenance on satellite communications systems aboard aircraft AirSatOne provides a live feed for monitored and evaluated, and eventually the flight paths and altitudes adjusted in order to lower the absorbed dose Geophysical Events from NOAA’s Space Weather Pre- diction Center. AirSatOne’s live feed [26] allows users to of the flight crews.[22][23][24] view observed and predicted space storms. Geophysical Alerts are important to flight crews and maintenance per- 1.6.2 Fauna and flora sonnel to determine if any upcoming activity or history has or will have an effect on satellite communications, Possibly the most closely studied of the variable Sun’s bi- GPS navigation and HF Communications. ological effects has been the degradation of homing pi- The telegraph lines in the past were affected by geomag- geons' navigational abilities during geomagnetic storms. netic storms as well. The telegraphs used a single long Pigeons and other migratory animals, such as dolphins wire for the data line, stretching for many miles, using and whales, demonstrate magnetosensitive behavioral re- ground as the return wire and being fed with DC power sponses that were once thought to be mediated by neu- from a battery; this made them (together with the power rons which contained the mineral magnetite located in lines mentioned below) susceptible to being influenced the beak. However, the basis of sensory perception of by the fluctuations caused by the ring current. The volt- magnetic fields is currently unknown.[25] age/current induced by the geomagnetic storm could have led to diminishing of the signal, when subtracted from the battery polarity, or to overly strong and spurious sig- 1.6.3 Disruption of electrical systems nals when added to it; some operators in such cases even learned to disconnect the battery and rely on the induced Odenwald suggests that a geomagnetic storm on the scale current as their power source. In extreme cases the in- of the solar storm of 1859 today would cause billions duced current was so high the coils at the receiving side of dollars of damage to satellites, power grids and radio burst in flames, or the operators received electric shocks. communications, and could cause electrical blackouts on Geomagnetic storms affect also long-haul telephone lines, a massive scale that might not be repaired for weeks. [11] including undersea cables unless they are fiber optic.[27] Damage to communications satellites can disrupt non- Communications terrestrial telephone, television, radio, and Internet links.[28] The National Academy of Sciences reported in Many communication systems use the ionosphere to re- 2008 on possible scenarios of widespread disruption in [29] flect radio signals over long distances. Ionospheric storms the 2012–2013 solar peak. can affect radio communication at all latitudes. Some radio frequencies are absorbed and others are reflected, leading to rapidly fluctuating signals and unexpected Navigation systems propagation paths. TV and commercial radio stations are little affected by solar activity, but ground-to-air, ship- Systems such as GPS, LORAN, and the now-defunct to-shore, shortwave broadcast, and amateur radio (mostly OMEGA are adversely affected when solar activity dis- the bands below 30 MHz) are frequently disrupted. Ra- rupts their signal propagation. The OMEGA system con- dio operators using HF bands rely upon solar and geo- sisted of eight transmitters located throughout the world. magnetic alerts to keep their communication circuits up Airplanes and ships used the very low frequency signals and running. from these transmitters to determine their positions. Dur- Some military detection or early warning systems are also ing solar events and geomagnetic storms, the system gave affected by solar activity. The over-the-horizon radar navigators information that is inaccurate by as much as bounces signals off the ionosphere to monitor the launch several miles. If navigators had been alerted that a proton of aircraft and missiles from long distances. During geo- event or geomagnetic storm was in progress, they could magnetic storms, this system can be severely hampered by have switched to a backup system. radio clutter. Some submarine detection systems use the GPS signals are affected when solar activity causes sud- magnetic signatures of submarines as one input to their den variations in the density of the ionosphere, causing locating schemes. Geomagnetic storms can mask and dis- the GPS signals to scintillate (like a twinkling star). The tort these signals. scintillation of satellite signals during ionospheric distur- 1.6. GEOMAGNETIC STORM EFFECTS 5

bances is studied at HAARP during ionospheric mod- one component, it may attempt to neutralize by discharg- ification experiments. It has also been studied at the ing to other components. This discharge is potentially Jicamarca Radio Observatory. hazardous to the satellite’s electronic systems. One technology used to allow GPS receivers to continue to operate in the presence of some confusing signals is Receiver Autonomous Integrity Monitoring (RAIM). However, RAIM is predicated on the assumption that a Mains electricity grid majority of the GPS constellation is operating properly, and so it is much less useful when the entire constellation is perturbed by global influences such as geomagnetic When magnetic fields move about in the vicinity of a con- storms. Even if RAIM detects a loss of integrity in these ductor such as a wire, a geomagnetically induced cur- cases, it may not be able to provide a useful, reliable sig- rent is produced in the conductor. This happens on a nal. grand scale during geomagnetic storms (the same mech- anism also influenced telephone and telegraph lines before fiber optics, see above) on all long transmission lines. Satellite hardware damage Long transmission lines (many kilometers in length) are thus subject to damage by this effect. Notably, this Geomagnetic storms and increased solar ultraviolet emis- chiefly includes operators in China, North America, and sion heat Earth’s upper atmosphere, causing it to ex- Australia, especially in more modern high-voltage, low- pand. The heated air rises, and the density at the orbit resistance lines. The European grid consists mainly of of satellites up to about 1,000 km (621 mi) increases sig- shorter transmission circuits, which are less vulnerable to nificantly. This results in increased drag on satellites in damage.[30][31] space, causing them to slow and change orbit slightly. Un- The (nearly direct) currents induced in these lines from less Low Earth Orbit satellites are routinely boosted to geomagnetic storms are harmful to electrical transmis- higher orbits, they slowly fall, and eventually burn up in sion equipment, especially transformers — inducing core Earth’s atmosphere. saturation, constraining their performance (as well as Skylab is an example of a spacecraft reentering Earth’s tripping various safety devices), and causing coils and atmosphere prematurely in 1979 as a result of higher- cores to heat up. In extreme cases, this heat can dis- than-expected solar activity. During the great geomag- able or destroy them, even inducing a chain reaction that netic storm of March 1989, four of the Navy’s naviga- can overload transformers throughout a system.[32][33][34] tional satellites had to be taken out of service for up to a Most generators are connected to the grid via transform- week, the U.S. Space Command had to post new orbital ers, isolating them from the induced currents on the elements for over 1000 objects affected, and the Solar grid, making them much less susceptible to damage due Maximum Mission satellite fell out of orbit in December to geomagnetically induced current. However, a trans- the same year. former that is subjected to this will act as an unbalanced load to the generator, causing negative sequence current The vulnerability of the satellites depends on their posi- in the stator and consequently heating of the rotor. tion as well. The South Atlantic Anomaly is a perilous place for a satellite to pass through. According to a study by Metatech corporation, a storm with a strength comparable to that of 1921 would destroy As technology has allowed spacecraft components to be- more than 300 transformers and leave over 130 million come smaller, their miniaturized systems have become people without power, with a cost totaling several trillion increasingly vulnerable to the more energetic solar par- dollars.[35] A massive solar flare could knock out elec- ticles. These particles can cause physical damage to mi- tric power for months.[36] These predictions are contra- crochips and can change software commands in satellite- dicted by a NERC report that concludes that a geomag- borne computers. netic storm would cause temporary grid instability but Another problem for satellite operators is differential no widespread destruction of high-voltage transformers. charging. During geomagnetic storms, the number and The report points out that the widely quoted Quebec grid energy of electrons and ions increase. When a satellite collapse was not caused by overheating transformers but travels through this energized environment, the charged by the near-simultaneous tripping of seven relays.[37] particles striking the spacecraft cause different portions By receiving geomagnetic storm alerts and warnings of the spacecraft to be differentially charged. Eventu- (e.g. by the Space Weather prediction Center; via Space ally, electrical discharges can arc across spacecraft com- Weather satellites as SOHO or ACE), power companies ponents, harming and possibly disabling them. can minimize damage to power transmission equipment, Bulk charging (also called deep charging) occurs when by momentarily disconnecting transformers or by induc- energetic particles, primarily electrons, penetrate the ing temporary blackouts. Preventative measures also ex- outer covering of a satellite and deposit their charge in ist, including preventing the inflow of GICs into the grid its internal parts. If sufficient charge accumulates in any through the neutral-to-ground connection.[30] 6 CHAPTER 1. GEOMAGNETIC STORM

Geologic exploration 1.8 See also

Earth’s magnetic field is used by geologists to determine • A-index subterranean rock structures. For the most part, these • geodetic surveyors are searching for oil, gas, or mineral K-index deposits. They can accomplish this only when Earth’s • Advanced Composition Explorer field is quiet, so that true magnetic signatures can be detected. Other geophysicists prefer to work during geo- • Electromagnetic pulse magnetic storms, when strong variations in the Earth’s • Geomagnetic reversal normal subsurface electric currents allow them to sense subsurface oil or mineral structures. This technique is • List of solar storms called magnetotellurics. For these reasons, many surveyors use geomagnetic alerts and predictions to schedule • Magnetar their mapping activities. • Solar and Heliospheric Observatory • Solar flare Pipelines • STEREO Rapidly fluctuating geomagnetic fields can produce • List of plasma (physics) articles geomagnetically induced currents in pipelines. This can cause multiple problems for pipeline engineers. Flow me- ters in the pipeline can transmit erroneous flow informa- 1.9 References tion, and the corrosion rate of the pipeline is dramatically increased.[38][39] If engineers incorrectly attempt to bal- [1] Corotating Interaction Regions, Corotating Interaction Re- ance the current during a geomagnetic storm, corrosion gions Proceedings of an ISSI Workshop, 6–13 June 1998, rates may increase even more. Once again, pipeline man- Bern, Switzerland, Springer (2000), Hardcover, ISBN agers thus receive space weather alerts and warnings to 978-0-7923-6080-3, Softcover, ISBN 978-90-481-5367- allow them to implement defensive measures. 1

[2] “Scientists probe northern lights from all angles”. CBC. 22 October 2005.

1.7 Preparations against solar [3] “Earth dodges magnetic storm”. New Scientist. 24 June storms 1989. [4] S. Chapman, V. C. A. Ferraro (1930). “A New The- Although geomagnetic storms that are severe enough to ory of Magnetic Storms”. Nature 129 (3169): 129–130. cause damage to the mains electricity grid are rare, there Bibcode:1930Natur.126..129C. doi:10.1038/126129a0. are some people who actively prepare against such events. [5] V. C. A. Ferraro (1933). “A New Theory of Magnetic To eliminate the possibility of damage to private electri- Storms: A Critical Survey”. The Observatory 56: 253– cal equipment, houses can be protected with a (double- 259. Bibcode:1933Obs....56..253F. pole) circuit breaker on the power line that enters the [6] Gonzalez, W. D., J. A. Joselyn, Y. Kamide, H. W. Kroehl, [40][41][42][43] house. Since long powerlines (such as the G. Rostoker, B. T. Tsurutani, and V. M. Vasyliunas ones coming from the mains electricity grid) gather and (1994), What is a Geomagnetic Storm?, J. Geophys. Res., convey a huge amount of electric power from the so- 99(A4), 5771–5792. lar storms, it is very likely that any connected domestic equipment that is connected to it will be damaged during [7] Sugiura, M., and T. Kamei, Equatorial Dst index 1957- 1986, IAGA Bulletin, 40, edited by A. BerthelJer and a powerful solar storm. M. MenvielleI,S GI Publ. Oﬀ., Saint. Maur-des-Fosses, Another technique often used is to place essential electri- France, 1991. cal equipment (such as electricity generators) in a card- [8] World Data Center for Geomagnetism, Kyoto board box lined with aluminum on the outside. This ef- fectively makes a Faraday cage, hence shielding the elec- [9] Russell, Randy (March 29, 2010). “Geomagnetic trical equipment from any radiation.[42][44] However, for Storms”. Windows to the Universe. National Earth Sci- radiation damage to occur, the geomagnetic storms would ence Teachers Association. Retrieved 4 August 2013. need to be very powerful, and/or the equipment would [10] Tsurutani, B. T.; Gonzalez, W. D.; Lakhina, G. be of a type that is very vulnerable to radiation damage. S.; Alex, S. (2003). “The extreme magnetic storm Also, simply placing the equipment inside your house will of 1–2 September 1859”. J. Geophys. Res. 108 already provide some protection against geomagnetic ra- (A7): 1268. Bibcode:2003JGRA..108.1268T. diation. doi:10.1029/2002JA009504. 1.10. FURTHER READING 7

[11] “Bracing the Satellite Infrastructure for a Solar Super- [29] Severe Space Weather Events—Understanding Societal storm”. Sci. Am. and Economic Impacts: Workshop Report. Washington, D.C: National Academies Press. 2008. ISBN 0-309- [12] “Extreme Space Weather Events”. National Geophysical 12769-6. Data Center. [30] “A Perfect Storm of Planetary Proportions”. IEEE Spec- [13] Bolduc 2002 trum. February 2012. Retrieved 2012-02-13. [14] “Geomagnetic Storms Can Threaten Electric Power [31] Natuurwetenschap & Techniek Magazine, June 2009 Grid”. Earth in Space (American Geophysical Union) 9 (7): 9–11. March 1997. [32] http://192.211.16.13/curricular/ENERGY/0708/ articles/solar/SolarForecast07SkyTel.pdf Solar Forecast: [15] High-voltage power grid disturbances during geomagnetic Storm AHEAD storms Stauning, P., Proceedings of the Second Solar Cy- cle and Space Weather Euroconference, 24–29 Septem- [33] Severe Space Weather Events: Understanding Societal ber 2001, Vico Equense, Italy. Editor: Huguette Sawaya- and Economic Impacts Lacoste. ESA SP-477, Noordwijk: ESA Publications Di- vision, ISBN 92-9092-749-6, 2002, p. 521 - 524 [34] Metatech Corporation Study

[16] Webber, W. R.; McDonald, F. B.; Lockwood, J. A.; [35] Severe Space Weather Events: Understanding Societal Heikkila, B. (2002). “The effect of the July 14, and Economic Impacts : a Workshop Report. Wash- 2000 “Bastille Day” solar flare event on >70 MeV ington, D.C.: National Academies, 2008 Web. 15 Nov. galactic cosmic rays observed at V1 and V2 in the 2011. Pages 78, 105, & 106. distant heliosphere”. Geophys. Res. Lett. 29 (10): 1377–1380. Bibcode:2002GeoRL..29.1377W. [36] “Massive solar flare 'could paralyse Earth in 2013'". The doi:10.1029/2002GL014729. Daily Mail. September 21, 2010.

[17] Thomson, N. R., C. J. Rodger, and R. L. Dowden (2004), [37] Eﬀects of Geomagnetic Disturbances on the Bulk Power Ionosphere gives size of greatest solar ﬂare, Geophys. Res. System. North American Electric Reliability Corpora- Lett. 31, L06803, doi:10.1029/2003GL019345 tion, February 2012.

[18] Halloween Space Weather Storms of 2003, NOAA Tech- [38] Gummow, R; Eng, P (2002). “GIC eﬀects on pipeline nical Memorandum OAR SEC-88, Space Environment corrosion and corrosion control systems”. Journal of Center, Boulder, Colorado, June 2004 Atmospheric and Solar-Terrestrial Physics 64 (16): 1755. Bibcode:2002JASTP..64.1755G. doi:10.1016/S1364- [19] Severe Space Weather Events - Understanding Societal 6826(02)00125-6. and Economic Impacts – Workshop Report, National Re- search Council of the National Academies, The National [39] Osella, A; Favetto, A; López, E (1998). “Currents Academies Press, Washington, D. C., 2008 induced by geomagnetic storms on buried pipelines as a cause of corrosion”. Journal of Applied Geo- [20] ‘Geomagnetic Storms,’ CENTRA Technology, Inc. re- physics 38 (3): 219. Bibcode:1998JAG....38..219O. port (14 January 2011) prepared for the Oﬃce of Risk doi:10.1016/S0926-9851(97)00019-0. Management and Analysis, United States Department of Homeland Security [40] Power line entering the house

[21] Snare, Robert C. “A History of Vector Magnetometry in [41] Power line entering the house: just after Point Of Service Space”. University of California. Retrieved 2008-03-18. [42] Protecting your home against geomagnetic storms [22] Evaluation of the Cosmic Ray Exposure of Aircraft Crew [43] Circuit breaker use on power line against geomagnetic [23] Sources and Effects of Ionizing Radiation, UNSCEAR storms 2008 [44] How to protect against a solar storm [24] Phillips, Tony (25 October 2013). “The Effects of Space Weather on Aviation”. Science News. NASA. [25] Kirschvink, Joseph; Gould, James (1981). “Biogenic 1.10 Further reading magnetite as a basis for magnetic field detection in animals” (PDF). BioSystems (Elsevier/North- • Holland Scientific Publishers Ltd.) 13 (3): 181–201. Bolduc, L. (2002). “GIC observations and doi:10.1016/0303-2647(81)90060-5. PMID 7213948. studies in the Hydro-Québec power sys- Retrieved 2012-07-13. tem”. J. Atmos. Sol. Terr. Phys. 64 (16): 1793–1802. Bibcode:2002JASTP..64.1793B. [26] “AirSatOne - Geophysical Alerts Live Feed”. doi:10.1016/S1364-6826(02)00128-1. [27] image.gsfc.nasa.gov • Campbell, W.H. (2001). Earth Magnetism: A [28] “Solar Storms Could Be Earth’s Next Katrina”. Retrieved Guided Tour Through Magnetic Fields. New York: 2010-03-04. Harcourt Sci. & Tech. ISBN 0-12-158164-0. 8 CHAPTER 1. GEOMAGNETIC STORM

• Carlowicz, M., and R. Lopez, Storms from the Sun, • Live solar and geomagnetic activity data (www. Joseph Henry Press, 2002, www.stormsfromthesun. spaceweatherlive.com) net • The warp and woof of a geomagnetic storm — • Davies, K. (1990). Ionospheric Radio. London: Pe- NASA's Space Science News. ter Peregrinus. • NOAA Space Weather Scales — NOAA. • Eather, R.H. (1980). Majestic Lights. Washington • DC: AGU. ISBN 0-87590-215-4. NOAA Space Weather Prediction Center - NOAA. • • Garrett, H.B., Pike, C.P., ed. (1980). Space Systems NOAA Space Weather Alerts — NOAA. and Their Interactions with Earth’s Space Environ- • NASA — Carrington Super Flare NASA May 6, ment. New York: American Institute of Aeronautics 2008 and Astronautics. ISBN 0-915928-41-8. • Ionosphere and thermosphere response to geomag- • Gauthreaux, S., Jr. (1980). “Ch. 5”. Animal Migra- netic storm simulated by a Coupled Magnetosphere tion: Orientation and Navigation. New York: Aca- Ionosphere Thermosphere model demic Press. ISBN 0-12-277750-6. • Real time magnetograms, updated every minute: al- • Harding, R. (1989). Survival in Space. New York: lows to display simultaneously and to compare the Routledge. ISBN 0-415-00253-2. geomagnetic storms in 8 observatories spread over • Joselyn J.A. (1992). “The impact of solar ﬂares the Earth (for example, Sudden Commencements and magnetic storms on humans”. EOS 73 are observed worldwide exactly at the same time). (7): 81, 84–5. Bibcode:1992EOSTr..73...81J. • AirSatOne:Recent Geophysical Alert Messages doi:10.1029/91EO00062.

• Johnson, N.L., McKnight, D.S. (1987). Artificial Aurora Watch, at Lancaster University, gives email warn- Space Debris. Malabar, Florida: Orbit Book. ISBN ings of coronal mass ejections and geomagnetic storms 0-89464-012-7. for aurora watching enthusiasts: • Lanzerotti, L.J. (1979). “Impacts of ionospheric / • magnetospheric process on terrestrial science and http://aurorawatch.lancs.ac.uk/ technology”. In Lanzerotti, L.J., Kennel, C.F., • http://geomag.usgs.gov Parker, E.N. Solar System Plasma Physics, III. New York: North Holland. • De Matteis G, Vellante M, Marrelli A et al. (Jan- uary 1994). “Geomagnetic activity, humidity, tem- • Odenwald, S. (2001). The 23rd Cycle:Learning to perature and headache: is there any correlation?". live with a stormy star. Columbia University Press. Headache 34 (1): 41–3. doi:10.1111/j.1526- ISBN 0-231-12079-6. 4610.1994.hed3401041.x. PMID 8132439. • Odenwald, S., 2003, “The Human Impacts of Space Weather”, http://www.solarstorms.org. Power grid related links • Stoupel, E., (1999) Effect of geomagnetic activity • Geomagnetic Storm Induced HVAC Transformer on cardiovascular parameters, Journal of Clinical Failure is Avoidable and Basic Cardiology, 2, Issue 1, 1999, pp 34–40. IN James A. Marusek (2007) Solar Storm Threat • NOAA Economics — Geomagnetic Storm datasets Analysis, Impact, Bloomfield, Indiana 47424 http: and Economic Research //www.breadandbutterscience.com/SSTA.pdf • Geomagnetic Storms Can Threaten Electric Power • Volland, H., (1984), “Atmospheric Electrodynam- Grid ics”, Kluwer Publ., Dordrecht

1.11 External links

Websites relating to coping with or measuring solar storms

• Solar Cycle 24 and VHF Aurora Website (www. solarcycle24.com) Chapter 2

Solar storm of 1859

was made possible by a prior CME, perhaps the cause of the large aurora event on August 29, that “cleared the way” of ambient solar wind plasma for the Carrington event.[4] Because of a simultaneous “crochet” observed in the Kew Observatory magnetometer record by Scottish physicist Balfour Stewart and a geomagnetic storm observed the following day, Carrington suspected a solar-terrestrial connection. Worldwide reports on the effects of the geomagnetic storm of 1859 were compiled and published by Elias Loomis, which support the observations of Car- rington and Stewart. Sunspots of September 1, 1859, as sketched by Richard Carring- ton. A and B mark the initial positions of an intensely bright On September 1–2, 1859, one of the largest recorded event, which moved over the course of five minutes to C and D geomagnetic storms (as recorded by ground-based mag- before disappearing. netometers) occurred. Aurorae were seen around the world, those in the northern hemisphere even as far The solar storm of 1859, also known as the Carring- south as the Caribbean; those over the Rocky Moun- ton event,[1] was a powerful geomagnetic solar storm in tains were so bright that their glow awoke gold miners, 1859 during solar cycle 10. A solar coronal mass ejec- who began preparing breakfast because they thought it tion hit Earth’s magnetosphere and induced one of the was morning.[4] People who happened to be awake in largest geomagnetic storms on record. The associated the northeastern US could read a newspaper by the au- “white light flare” in the solar photosphere was observed rora’s light.[5] The aurora was visible as far from the and recorded by English astronomers Richard C. Carring- poles as Sub-Saharan Africa (Senegal, Mauritania, per- ton and Richard Hodgson. haps Monrovia, Liberia), Monterey and Tampico in Mex- [6] Studies have shown that a solar storm of this magnitude ico, Queensland, Cuba and Hawaii. Aurorae were vis- occurring today would likely cause widespread problems ible at sea level at the latitudes of Port Moresby, Papua for modern civilization. The solar storm of 2012 was New Guinea and Dakar, Senegal; in theory at least, ob- of similar magnitude, but it passed Earth’s orbit without servers in the equatorial regions, particularly at higher el- striking the Earth.[2] evations, may have been able to see the aurora borealis and aurora australis simultaneously. A story about this in- deed being the case (the location usually given as the top of Mt Kilimanjaro and/or well up into the Andes) which 2.1 Carrington super flare has circulated for years probably refers to either this or the 25-26. January 1938 aurora.[7] The latter storm by From August 28 through September 2, 1859, numerous most measures was not as strong as the sequelae of the sunspots were observed on the Sun. On August 29, south- Carrington event in 1859, but the colour, shape, and per- ern aurorae were observed as far north as Queensland, sistent intensity of the 1938 aurorae (blood red over Eu- [3] Australia. Just before noon on September 1, the English rope and North America as well as the Southern Hemi- amateur astronomers Richard Carrington and Richard sphere) and the fact that it may have fit the second Fatima Hodgson independently made the first observations of prophecy[8] due to the impending Anschluß of Austria [4] a solar flare. The flare was associated with a major by Nazi Germany and noises about Poland being invaded coronal mass ejection (CME) that travelled directly to- at some point have led to the 1938 event being as well ward Earth, taking 17.6 hours to make the 93 million mile known or better than that in 1859. The European aurora journey. It is believed that the relatively high speed of this of 1707 was apparently intermediate betwixt the other CME (typical CMEs take several days to arrive at Earth)

9 10 CHAPTER 2. SOLAR STORM OF 1859 two storms.[9] 28, 2014.[2][18] Telegraph systems all over Europe and North Amer- ica failed, in some cases giving telegraph operators electric shocks.[10] Telegraph pylons threw sparks.[11] 2.3 See also Some telegraph operators could continue to send and receive messages despite having disconnected their power • 774–775 carbon-14 spike supplies.[12] • A-index On Saturday, September 3, 1859, the Baltimore American and Commercial Advertiser reported, “Those who hap- • March 1989 geomagnetic storm pened to be out late on Thursday night had an opportunity • of witnessing another magnificent display of the auroral K-index lights. The phenomenon was very similar to the display • List of solar storms on Sunday night, though at times the light was, if possible, more brilliant, and the prismatic hues more varied • Nuclear electromagnetic pulse and gorgeous. The light appeared to cover the whole fir- • mament, apparently like a luminous cloud, through which Solar cycle 10 the stars of the larger magnitude indistinctly shone. The light was greater than that of the moon at its full, but had an indescribable softness and delicacy that seemed to en- 2.4 References velop everything upon which it rested. Between 12 and 1 o'clock, when the display was at its full brilliancy, the [1] Philips, Tony (January 21, 2009). “Severe Space quiet streets of the city resting under this strange light, Weather--Social and Economic Impacts”. NASA Science: presented a beautiful as well as singular appearance.”[13] Science News (science.nasa.gov). Retrieved February 16, 2011. In June 2013, a joint venture from researchers at Lloyd’s of London and Atmospheric and Environmental Research [2] Phillips, Dr. Tony (July 23, 2014). “Near Miss: The So- (AER) in the United States used data from the Carrington lar Superstorm of July 2012”. NASA. Retrieved July 26, Event to estimate the current cost of a similar event to the 2014. [14] US alone at $0.6–2.6 trillion. [3] “SOUTHERN AURORA.”. The Moreton Bay Courier (Brisbane: National Library of Australia). 7 September 1859. p. 2. Retrieved 17 May 2013. 2.2 Similar events [4] Odenwald, Sten F.; Green, James L. (July 28, 2008). “Bracing the Satellite Infrastructure for a Solar Super- storm”. Scientific American. Retrieved February 16, Ice cores containing thin nitrate-rich layers have been an- 2011. alyzed to reconstruct a history of past solar storms pre- dating reliable observations. Data from Greenland ice [5] Richard A. Lovett (March 2, 2011). “What If the Biggest cores, gathered by Kenneth G. McCracken[15] and others, Solar Storm on Record Happened Today?". National Ge- show evidence that events of this magnitude—as mea- ographic News. Retrieved September 5, 2011. sured by high-energy proton radiation, not geomagnetic [6] “Monster radiation burst from Sun”. BBC News. 14 May effect—occur approximately once per 500 years, with 2013. Retrieved 15 May 2013. events at least one-fifth as large occurring several times per century.[16] However, more recent work by the ice [7] http://www.solarstorms.org/SS1938.html core community (McCracken et al. are space scientists) [8] http://www.solarstorms.org/SS1938.html shows that nitrate spikes are not a result of solar energetic particle events, so use of this technique is in doubt. [9] http://www.solarstorms.org/SS1938.html Beryllium-10 and Carbon-14 levels are considered to be [10] Committee on the Societal and Economic Impacts of Se- more reliable indicators by the ice core community.[17] vere Space Weather Events: A Workshop, National Re- These similar but much more extreme cosmic ray events, search Council (2008). Severe Space Weather Events-- however, may originate outside the solar system and even Understanding Societal and Economic Impacts: A Work- outside the galaxy. Less severe storms have occurred in shop Report. National Academies Press. p. 13. ISBN 1921 and 1960, when widespread radio disruption was 0-309-12769-6. reported. The March 1989 geomagnetic storm knocked out power across large sections of Quebec. On July 23, [11] Odenwald, Sten F. (2002). The 23rd Cycle. Columbia 2012 a “Carrington-class” Solar Superstorm (Solar flare, University Press. p. 28. ISBN 0-231-12079-6. Coronal mass ejection, Solar EMP) was observed; its tra- [12] Carlowicz, Michael J.; Lopez, Ramon E. (2002). Storms jectory missed Earth in orbit. Information about these from the Sun: The Emerging Science of Space Weather. observations was shared first publicly by NASA on April National Academies Press. p. 58. ISBN 0-309-07642-0. 2.5. FURTHER READING 11

[13] “The Aurora Borealis”. Baltimore American and Com- • Green, J.; Boardsen, S. (2006). “Duration mercial Advertiser. September 3, 1859. p. 2; Column and extent of the great auroral storm of 2. Retrieved February 16, 2011. 1859”. Advances in Space Research 38 (2): 130–135. Bibcode:2006AdSpR..38..130G. [14] Solar Storm Risk to the North American Electric Grid doi:10.1016/j.asr.2005.08.054. Lloyd’s 2013 • Silverman, S. (2006). “Comparison of the [15] “How do you determine the effects of a solar flare that aurora of September 1/2, 1859 with other took place 150 years ago?" (PDF). Stuart Clarks Universe. great auroras”. Advances in Space Research 38 Retrieved May 23, 2012. (2): 136–144. Bibcode:2006AdSpR..38..136S. [16] McCracken, K. G.; Dreschhoff, G. A. M.; Zeller, doi:10.1016/j.asr.2005.03.157. E. J.; Smart, D. F.; Shea, M. A. (2001). “So- • lar cosmic ray events for the period 1561–1994 Green, J.; Boardsen, S.; Odenwald, S.; Hum- 1. Identification in polar ice, 1561–1950”. ble, J.; Pazamickas, K. (2006). “Eyewit- Journal of Geophysical Research 106 (A10): ness reports of the great auroral storm of 21,585–21,598. Bibcode:2001JGR...10621585M. 1859”. Advances in Space Research 38 (2): doi:10.1029/2000JA000237. 145–154. Bibcode:2006AdSpR..38..145G. doi:10.1016/j.asr.2005.12.021. [17] Wolff, E. W.; Bigler, M.; Curran, M. A. J.; Dibb, J.; Frey, M. M.; Legrand, M. (2012). “The Car- • Humble, J. (2006). “The solar events of Au- rington event not observed in most ice core nitrate gust/September 1859 – Surviving Australian ob- records”. Geophysical Research Letters 39 (8): servations”. Advances in Space Research 38 21,585–21,598. Bibcode:2012GeoRL..39.8503W. (2): 155–158. Bibcode:2006AdSpR..38..155H. doi:10.1029/2012GL051603. doi:10.1016/j.asr.2005.08.053.

[18] “Video (04:03) – Carrington-class coronal mass ejection • Boteler, D. (2006). “The super storms of Au- narrowly misses Earth”. NASA. April 28, 2014. Re- gust/September 1859 and their effects on the tele- trieved July 26, 2014. graph system”. Advances in Space Research 38 (2): 159–172. Bibcode:2006AdSpR..38..159B. doi:10.1016/j.asr.2006.01.013. 2.5 Further reading • Siscoe, G.; Crooker, N.; Clauer, C. (2006). “Dst of the Carrington storm of 1859”. • Cliver, E. W.; Svalgaard, L. (2004). “The Advances in Space Research 38 (2): 173– 1859 Solar–Terrestrial Disturbance and 179. Bibcode:2006AdSpR..38..173S. the Current Limits of Extreme Space doi:10.1016/j.asr.2005.02.102. Weather Activity” (PDF). Solar Physics 224: 407. Bibcode:2004SoPh..224..407C. • Nevanlinna, H. (2006). “A study on the doi:10.1007/s11207-005-4980-z. great geomagnetic storm of 1859: Com- parisons with other storms in the 19th cen- • Tsurutani, B. T.; Gonzalez, W. D.; Lakhina, G. tury”. Advances in Space Research 38 (2): S.; Alex, S. (2003). “The extreme magnetic storm 180–187. Bibcode:2006AdSpR..38..180N. of 1–2 September 1859”. Journal of Geophysi- doi:10.1016/j.asr.2005.07.076. cal Research 108. Bibcode:2003JGRA..108.1268T. doi:10.1029/2002JA009504. • Kappenman, J. (2006). “Great geomagnetic storms and extreme impulsive geomagnetic field • Issue 2 of Volume 38, Pages 115-388 (2006), of disturbance events – An analysis of observa- Advances in Space Research, an issue entitled “The tional evidence including the great storm of Great Historical Geomagnetic Storm of 1859: A May 1921”. Advances in Space Research 38 Modern Look” (2): 188–199. Bibcode:2006AdSpR..38..188K. doi:10.1016/j.asr.2005.08.055. • Robertclauer, C.; Siscoe, G. (2006). “The great historical geomagnetic storm of 1859: A mod- • Silverman, S. (2006). “Low latitude auro- ern look”. Advances in Space Research 38 ras prior to 1200 C.E. and Ezekiel’s vi- (2): 117–118. Bibcode:2006AdSpR..38..117R. sion”. Advances in Space Research 38 (2): doi:10.1016/j.asr.2006.09.001. 200–208. Bibcode:2006AdSpR..38..200S. doi:10.1016/j.asr.2005.03.158. • Cliver, E. (2006). “The 1859 space weather event: Then and now”. Advances in Space Research 38 • Shea, M.; Smart, D. (2006). “Geomagnetic (2): 119–129. Bibcode:2006AdSpR..38..119C. cutoff rigidities and geomagnetic coordi- doi:10.1016/j.asr.2005.07.077. nates appropriate for the Carrington flare 12 CHAPTER 2. SOLAR STORM OF 1859

Epoch”. Advances in Space Research 38 (2): • Wilson, L. (2006). “Excerpts from and Comments 209–214. Bibcode:2006AdSpR..38..209S. on the Wochenschrift für Astronomie, Meteorolo- doi:10.1016/j.asr.2005.03.156. gie und Geographie, Neue Folge, zweiter Jahrgang (new series 2)". Advances in Space Research 38 • Smart, D.; Shea, M.; McCracken, K. (2006). “The (2): 304–312. Bibcode:2006AdSpR..38..304W. Carrington event: Possible solar proton intensity– doi:10.1016/j.asr.2006.07.004. time profile”. Advances in Space Research 38 (2): 215–225. Bibcode:2006AdSpR..38..215S. • Shea, M.; Smart, D. (2006). “Compendium doi:10.1016/j.asr.2005.04.116. of the eight articles on the “Carrington Event” • Townsend, L. W.; Stephens, D. L.; Hoff, J. L.; attributed to or written by Elias Loomis in Zapp, E. N.; Moussa, H. M.; Miller, T. M.; Camp- the American Journal of Science, 1859– bell, C. E.; Nichols, T. F. (2006). “The Carring- 1861”. Advances in Space Research 38 (2): ton event: Possible doses to crews in space from 313–385. Bibcode:2006AdSpR..38..313S. a comparable event”. Advances in Space Research doi:10.1016/j.asr.2006.07.005. 38 (2): 226–231. Bibcode:2006AdSpR..38..226T. doi:10.1016/j.asr.2005.01.111. 2.6 External links • Shea, M.; Smart, D.; McCracken, K.; Dreschhoff, G.; Spence, H. (2006). “Solar proton events • Carrington, R. C. (1859). “Description of a Sin- for 450 years: The Carrington event in per- gular Appearance seen in the Sun on September 1, spective”. Advances in Space Research 38 1859”. Monthly Notices of the Royal Astronomical (2): 232–238. Bibcode:2006AdSpR..38..232S. Society 20: 13–5. Bibcode:1859MNRAS..20...13C. doi:10.1016/j.asr.2005.02.100. doi:10.1093/mnras/20.1.13. • Burke, W.; Huang, C.; Rich, F. (2006). “Ener- • getics of the April 2000 magnetic superstorm ob- Bell, Trudy E.; Phillips, Tony (May 6, 2008). served by DMSP”. Advances in Space Research “A Super Solar Flare”. Science@NASA (sci- 38 (2): 239–252. Bibcode:2006AdSpR..38..239B. ence.nasa.gov). doi:10.1016/j.asr.2005.07.085. • Brooks, Michael (March 23, 2009). “Space storm • Manchester IV, W. B.; Ridley, A. J.; Gom- alert: 90 seconds from catastrophe”. New Scien- bosi, T. I.; De Zeeuw, D. L. (2006). “Mod- tist (www.newscientist.com). Retrieved March 28, eling the Sun-to-Earth propagation of a very 2009. fast CME”. Advances in Space Research 38 • “The Largest Magnetic Storm on Record, The “Car- (2): 253–262. Bibcode:2006AdSpR..38..253M. rington Event” of August 27 to September 7, 1859”. doi:10.1016/j.asr.2005.09.044. British Geological Survey (National Environment • Ridley, A. J.; De Zeeuw, D. L.; Manchester, Research Council). 2011. Retrieved March 28, W. B.; Hansen, K. C. (2006). “The magne- 2009. tospheric and ionospheric response to a very • strong interplanetary shock and coronal mass Clark, Stuart (2007). The Sun Kings: The Unex- ejection”. Advances in Space Research 38 (2): pected Tragedy of Richard Carrington and the Tale 263–272. Bibcode:2006AdSpR..38..263R. of How Modern Astronomy Began. ISBN 978-0- doi:10.1016/j.asr.2006.06.010. 691-12660-9. • Li, X.; Temerin, M.; Tsurutani, B.; Alex, S. • Excerpts of Articles from Newspapers concerning (2006). “Modeling of 1–2 September 1859 su- the Carrington Event. per magnetic storm”. Advances in Space Research 38 (2): 273–279. Bibcode:2006AdSpR..38..273L. doi:10.1016/j.asr.2005.06.070. • Odenwald, S.; Green, J.; Taylor, W. (2006). “Fore- casting the impact of an 1859-calibre superstorm on satellite resources”. Advances in Space Research 38 (2): 280–297. Bibcode:2006AdSpR..38..280O. doi:10.1016/j.asr.2005.10.046. • Boteler, D. (2006). “Comment on time con- ventions in the recordings of 1859”. Ad- vances in Space Research 38 (2): 301– 303. Bibcode:2006AdSpR..38..301B. doi:10.1016/j.asr.2006.07.006. Chapter 3

March 1989 geomagnetic storm

Some satellites in polar orbits lost control for several hours. GOES weather satellite communications were interrupted, causing weather images to be lost. NASA’s TDRS-1 communication satellite recorded over 250 anomalies caused by the increased particles ﬂowing into its sensitive electronics.[5] The Space Shuttle Discov- ery was having its own problems: a sensor on one of the tanks supplying hydrogen to a fuel cell was showing un- usually high pressure readings on March 13. The problem went away after the solar storm subsided. Artist’s depiction of solar wind colliding with Earth’s magnetosphere (size and distance are not to scale) 3.2 Quebec blackout The March 1989 geomagnetic storm was a severe geomagnetic storm that caused the collapse of Hydro- Québec’s electricity transmission system. It occurred during solar cycle 22.

3.1 Geomagnetic storm and auroras

The geomagnetic storm causing this event was itself the result of a coronal mass ejection on March 9, 1989.[1] A few days before, on March 6, a very large X15-class solar flare also occurred.[2] Three and a half days later, at 2:44 am EST on March 13, a severe geomagnetic storm struck Earth.[3][4] The storm began on Earth with extremely intense auroras at the poles. The aurora could be seen as GOES-7 monitors the space weather conditions during the Great [5] far south as Texas and Florida. As this occurred dur- Geomagnetic storm of March 1989, the Moscow neutron monitor ing the Cold War, an unknown number of people worried recorded the passage of a CME as a drop in levels known as a that a nuclear first-strike might be in progress.[5] Others Forbush decrease.[7] considered the intense auroras to be associated with the Space Shuttle mission STS-29, which had been launched The variations in the earth’s magnetic field also tripped on March 13 at 9:57:00 AM.[6] The burst caused short- circuit breakers on Hydro-Québec's power grid. The util- wave radio interference, including the disruption of radio ity’s very long transmission lines and the fact that most of signals from Radio Free Europe into Russia. It was ini- Quebec sits on a large rock shield prevented current flow- tially believed that the signals had been jammed by the ing through the earth, finding a less resistant path along Soviet government. the 735 kV power lines.[8] As midnight came and went, a river of charged particles The James Bay network went offline in less than 90 sec- and electrons in the ionosphere flowed from west to east, onds, giving Quebec its second massive blackout in 11 inducing powerful electrical currents in the ground that months.[9] The power failure lasted nine hours and forced surged into many natural nooks and crannies.[5] the company to implement various mitigation strategies,

13 14 CHAPTER 3. MARCH 1989 GEOMAGNETIC STORM

including raising the trip level, installing series compen- [9] Morin, Michel; Sirois, Gilles; Derome, Bernard (13 sation on ultra high voltage lines and upgrading various March 1989). “Le Québec dans le noir” (in French). monitoring and operational procedures. Other utilities in Radio-Canada. Retrieved 2009-03-21. North America and Northern Europe and elsewhere im- [10] Solar storms halt stock market as computers crash, New plemented programs to reduce the risks associated with Scientist, 9 September 1989. geomagnetically induced currents.[8] [11] Federal Energy Regulatory Commission. Transmission Planning and Cost Allocation by Transmission Owning 3.3 Aftermath and Operating Public Utilities. Retrieved 2013-04-23. [12] 77 FR 16175 In August 1989, another storm caused a halt of all trading on Toronto's stock market.[10] Since 1995, geomagnetic storms and solar ﬂares have been monitored from the Solar and Heliospheric Obser- vatory (SOHO) satellite, a joint project of NASA and the European Space Agency. Because of serious concerns that utilities have failed to set protection standards and are unprepared for a severe solar storm such as a Carrington Event, the Federal Energy Regulatory Commission (FERC) is now (as of 2013) in the process of a proposed ruling that may require utilities to create a standard that would require power grids to be protected from severe solar storms.[11] Similarly, the Nu- clear Regulatory Commission has begun a phased rule- making, published in the Federal Register, to examine the suﬃciency of cooling systems of stored spent fuel rods of nuclear power plants now considered vulnerable to long term power outages from events such as space weather, high-altitude nuclear burst electromagnetic pulse or cy- ber attacks.[12]

3.4 See also

• List of solar storms

3.5 References

[1] Geomagnetic Storms Can Threaten Electric Power Grid Earth in Space, Vol. 9, No. 7, March 1997, pp.9-11 (American Geophysical Union)

[2] http://sohowww.nascom.nasa.gov/hotshots/X17/

[3] Lerner, Eric J. (August 1995). “Space weather: Page 1”. Discover. Retrieved 2008-01-20.

[4] “Scientists probe northern lights from all angles”. CBC News. 2005-10-22. Retrieved 2008-01-13.

[5] “A Conﬂagration of Storms”. Retrieved 2009-04-07.

[6] “STS-29”. Science.ksc.nasa.gov. Retrieved 2010-08-09.

[7] “Extreme Space Weather Events”. National Geophysical Data Center.

[8] Hydro-Québec. “Understanding Electricity - March 1989 - Hydro-Québec”. Retrieved 2010-10-25. Chapter 4

Solar and Heliospheric Observatory

The Solar and Heliospheric Observatory (SOHO) is ing out an elliptical lissajous orbit centered about L1. It a spacecraft built by a European industrial consortium orbits L1 once every six months, while L1 itself orbits the led by Matra Marconi Space (now Astrium) that was Sun every 12 months as it is coupled with the motion of launched on a Lockheed Martin Atlas II AS launch ve- the Earth. This keeps SOHO at a good position for com- hicle on December 2, 1995 to study the Sun, and has dis- munication with Earth at all times. covered over 2700 comets.[1] It began normal operations in May 1996. It is a joint project of international coop- eration between the European Space Agency (ESA) and NASA. Originally planned as a two-year mission, SOHO 4.2 Communication with Earth continues to operate after over 19 years in space. In June 2013, a mission extension lasting until December 2016 In normal operation the spacecraft transmits a continu- was approved.[2] ous 200 kbit/s data stream of photographs and other measurements via the NASA Deep Space Network of ground In addition to its scientific mission, it is the main source stations. SOHO's data about solar activity are used to pre- of near-real-time solar data for space weather prediction. dict coronal mass ejection (CME) arrival times at earth, Along with the GGS Wind and Advanced Composition so electrical grids and satellites can be protected from Explorer (ACE) (and DSCOVR in 2015), SOHO is one their damaging effects. CMEs directed toward the earth of three spacecraft in the vicinity of the Earth–Sun L1 may produce geomagnetic storms, which in turn produce point, a point of gravitational balance located approxi- geomagnetically induced currents, in the most extreme mately 0.99 astronomical unit (AU)s from the Sun and cases creating black-outs, etc. 0.01 AU from the Earth. In addition to its scientific con- tributions, SOHO is distinguished by being the first three- In 2003 ESA reported the failure of the antenna Y-axis axis-stabilized spacecraft to use its reaction wheels as a stepper motor, necessary for pointing the high-gain an- kind of virtual gyroscope; the technique was adopted af- tenna and allowing the downlink of high-rate data. At the ter an on-board emergency in 1998 that nearly resulted in time, it was thought that the antenna anomaly might cause the loss of the spacecraft. two- to three-week data-blackouts every three months.[3] However, ESA and NASA engineers managed to use SOHO's low-gain antennas together with the larger 34 and 70 meter DSN ground stations and judicious use of 4.1 Orbit SOHO's Solid State Recorder (SSR) to prevent total data loss, with only a slightly reduced data flow every three months.[4] The SOHO spacecraft is in a halo orbit around the Sun– Earth L1 point, the point between the Earth and the Sun where the balance of the (larger) Sun’s gravity and the (smaller) Earth’s gravity is equal to the centripetal force 4.3 Near loss of SOHO needed for an object to have the same orbital period in its orbit around the Sun as the Earth, with the result that the The SOHO Mission Interruption sequence of events be- object will stay in that relative position. gan on June 24, 1998, while the SOHO Team was con- Although sometimes described as being at L1, the SOHO ducting a series of spacecraft gyroscope calibrations and spacecraft is not exactly at L1 as this would make com- maneuvers. Operations proceeded until 23:16 UTC when munication difficult due to radio interference generated SOHO lost lock on the Sun, and entered an emergency by the Sun, and because this would not be a stable or- attitude control mode called Emergency Sun Reacquisi- bit. Rather it lies in the (constantly moving) plane which tion (ESR). The SOHO Team attempted to recover the passes through L1 and is perpendicular to the line con- observatory, but SOHO entered the emergency mode necting the Sun and the Earth. It stays in this plane, trac- again on June 25 02:35 UTC. Recovery efforts contin-

15 16 CHAPTER 4. SOLAR AND HELIOSPHERIC OBSERVATORY ued, but SOHO entered the emergency mode for the last • Weiss, K. A.; Leveson, N.; Lundqvist, K.; Farid, time at 04:38 UTC. All contact with SOHO was lost, and N.; Stringfellow, M. (2001). “An analysis of cau- the mission interruption had begun. SOHO was spinning, sation in aerospace accidents”. Digital Avionics losing electrical power, and no longer pointing at the Sun. Systems, 2001. DASC. 20th Conference (IEEE) 1. Expert ESA personnel were immediately dispatched from doi:10.1109/DASC.2001.963364. ISBN 0-7803- Europe to the United States to direct operations. Days 7034-1. passed without contact from SOHO. On July 23, the • Leveson, N. G. (July 2004). “The Role of Software Arecibo Observatory and DSN antennas were used to lo- in Spacecraft Accidents”. AIAA Journal of Space- cate SOHO with radar, and to determine its location and craft and Rockets 41 (4). attitude. SOHO was close to its predicted position, oriented with its side versus the usual front Optical Surface • Neumann, Peter G. (January 1999). “Risks Reflector panel pointing toward the Sun, and was rotat- to the Public in Computers and Related Sys- ing at one RPM. Once SOHO was located, plans for con- tems”. Software Engineering Notes 24 (1): 31–35. tacting SOHO were formed. On August 3 a carrier was doi:10.1145/308769.308773. detected from SOHO, the first signal since June 25. Af- ter days of charging the battery, a successful attempt was made to modulate the carrier and downlink telemetry on 4.4 Scientific objectives August 8. After instrument temperatures were down- linked on August 9, data analysis was performed, and The three main scientific objectives of SOHO are: planning for the SOHO recovery began in earnest. The SOHO Recovery Team began by allocating the lim- • Investigation of the outer layer of the Sun, which ited electrical power. After this, SOHO’s anomalous ori- consists of the chromosphere, transition region, and entation in space was determined. Thawing the frozen the corona. CDS, EIT, LASCO, SUMER, SWAN, hydrazine fuel tank using SOHO’s thermal control heaters and UVCS are used for this solar atmosphere remote began on August 12. Thawing pipes and the thrusters sensing. was next, and SOHO was re-oriented towards the Sun on • September 16. After nearly a week of spacecraft bus Making observations of solar wind and associated recovery activities and an orbital correction maneuver, phenomena in the vicinity of L1. CELIAS and the SOHO spacecraft (bus) returned to normal mode on CEPAC are used for "in situ" solar wind observa- September 25 at 19:52 UTC. Recovery of the instruments tions. began on October 5 with SUMER, and ended on October • Probing the interior structure of the Sun. GOLF, 24, 1998 with CELIAS. MDI, and VIRGO are used for helioseismology. Only one gyro remained operational after this recovery, and on December 21 that gyro failed. Attitude control was accomplished with manual thruster firings that con- 4.5 Instruments sumed 7 kg of fuel weekly, while the ESA developed a new gyroless operations mode that was successfully im- The SOHO Payload Module (PLM) consists of twelve in- plemented on February 1, 1999. struments, each capable of independent or coordinated observation of the Sun or parts of the Sun, and some [5][6] 4.3.1 Additional references spacecraft components. The instruments are:

• “SOHO’s Recovery – An Unprecedented Success • Coronal Diagnostic Spectrometer (CDS) which Story” (PDF). Retrieved 2006-03-11. -PDF measures density, temperature and ﬂows in the corona. • “SOHO Mission Interruption Preliminary Status • and Background Report – July 15, 1998”. Retrieved Charge ELement and Isotope Analysis System 2006-03-11. (CELIAS) which studies the ion composition of the solar wind. • “SOHO Mission Interruption Joint NASA/ESA In- • vestigation Board Final Report – August 31, 1998”. Comprehensive SupraThermal and Energetic Retrieved 2006-03-11. Particle analyser collaboration (COSTEP) which studies the ion and electron composition of • “SOHO Recovery Team”. Retrieved 2006-03-11. the solar wind. COSTEP and ERNE are sometimes Image referred to together as the COSTEP-ERNE Particle Analyzer Collaboration (CEPAC). • “The SOHO Mission L1 Halo Orbit Recovery From the Attitude Control Anomalies of 1998” (PDF). • Extreme ultraviolet Imaging Telescope (EIT) Retrieved 2007-07-25. which studies the low coronal structure and activity. 4.5. INSTRUMENTS 17

• Energetic and Relativistic Nuclei and Electron parties can contact the instrument teams directly via e- experiment (ERNE) which studies the ion and mail and the SOHO web site to request time via that in- electron composition of the solar wind. (See note strument team’s internal processes (some of which are above in COSTEP entry.) quite informal, provided that the ongoing reference observations are not disturbed). A formal process (the • Global Oscillations at Low Frequencies (GOLF) “JOP” program) does exist for using multiple SOHO in- which measures velocity variations of the whole so- struments collaboratively on a single observation. JOP lar disk to explore the core of the Sun. proposals are reviewed at the quarterly Science Work- ing Team (“SWT”) meetings, and JOP time is allocated • Large Angle and Spectrometric Coronagraph at monthly meetings of the Science Planning Working (LASCO) which studies the structure and evolution Group. First results have been presented in Solar Physics, of the corona by creating an artificial solar eclipse. volumes 170 and 175 (1997), edited by B. Fleck and Z. Švestka. • Michelson Doppler Imager (MDI) which measures velocity and magnetic fields in the photosphere to learn about the convection zone which forms the 4.5.2 Comet discovery outer layer of the interior of the Sun and about the magnetic fields which control the structure of the As a consequence of its observing the Sun, SOHO (specif- corona. The MDI is the biggest producer of data by ically the LASCO instrument) has inadvertently allowed far on SOHO. In fact, two of SOHO’s virtual chan- the discovery of comets by blocking out the Sun’s glare. nels are named after MDI, VC2 (MDI-M) carries Approximately one-half of all known comets have been MDI magnetogram data, and VC3 (MDI-H) carries spotted by SOHO, discovered over the last 15 years MDI Helioseismology data. by over 70 people representing 18 different countries searching through the publicly available SOHO images • Solar Ultraviolet Measurement of Emitted Ra- online. Michał Kusiak of the Polish Jagiellonian Uni- diation (SUMER) which measures plasma flows, versity (Uniwersytet Jagielloński) discovered SOHO’s temperature and density in the corona. 1999th and 2000th comets on 26 December 2010.[9] As of April 2014, SOHO has discovered over 2700 • Solar Wind ANisotropies ([SWAN]) which uses comets,[1][10] with an average discovery rate of every 2.59 telescopes sensitive to a characteristic wavelength of days.[11] hydrogen to measure the solar wind mass flux, map the density of the heliosphere, and observe the large- Amateur astronomer Mike Oates’ discovery of over 140 scale structure of the solar wind streams. comets in the SOHO data[12] resulted in the minor planet “68948 Mikeoates” being named after him; this was • UltraViolet Coronagraph Spectrometer (UVCS) used by lexicographer Erin McKean in her TED talk which measures density and temperature in the as an example of how Internet users can contribute to corona. collections.[13]

• Variability of solar IRradiance and Gravity Os- SOHO 2198 is a Sungrazing Comet discovered by Indian amateur astronomer Salil Mulye and Polish astronomer cillations (VIRGO) which measures oscillations [14] and solar constant both of the whole solar disk and at Szymon Liwo. by analyzing data from the Solar and low resolution, again exploring the core of the Sun. Heliospheric Observatory. Large Angle and Spectromet- ric Coronagraph aboard SOHO is used to capture digital images of Sun. One such sungrazing comet, SOHO 2198 4.5.1 Public availability of images was discovered using LASCO images.This sungrazer be- longs to a family called Kreutz Sungrazers.With this discovery on 13 December 2011, Mulye became the second Observations from some of the instruments can be for- Indian to discover a sungrazing comet.[15] matted as images, most of which are also readily available on the internet for either public or research use (see the oﬃcial website). Others such as spectra and measure- 4.5.3 Instrument contributors ments of particles in the solar wind do not lend themselves so readily to this. These images range in wavelength or The Max Planck Institute for Solar System Research frequency from optical (Hα) to extreme ultraviolet (UV). contributed to SUMER, LASCO and CELIAS instru- Images taken partly or exclusively with non-visible wave- ments. The Smithsonian Astrophysical Observatory built lengths are shown on the SOHO page and elsewhere in the UVCS instrument. The Lockheed Martin Solar and false color. Astrophysics Laboratory (LMSAL) built the MDI instru- Unlike many space-based and ground telescopes, there is ment in collaboration with the solar group at Stanford no time formally allocated by the SOHO program for ob- University. The Institut d'Astrophysique Spatiale is the serving proposals on individual instruments: interested principal investigator of GOLF and EIT, with a strong 18 CHAPTER 4. SOLAR AND HELIOSPHERIC OBSERVATORY contribution to SUMER. 4.8 External links

• ESA SOHO webpage 4.6 See also • SOHO Homepage • Heliophysics • “A Description of the SOHO Mission”. NASA’s • Solar Dynamics Observatory (SDO), launched SOHO website. Retrieved 24 October 2005. 2010, still operational. • “Latest SOHO Images”. NASA’s SOHO website. Re- • STEREO (Solar TErrestrial RElations Observa- trieved 24 October 2005., free to use for educational tory), launched 2006, still operational. and non-commercial purposes. • Transition Region and Coronal Explorer (TRACE), • SOHO Mission Proﬁle by NASA’s Solar System Ex- launched 1998, decommissioned 2010. ploration

• Triana, satellite intended for L1 • “Space Weather Now”. National Weather Service – Space Environment Center. Retrieved 24 October • High Resolution Coronal Imager (Hi-C), launched 2005. 2012, sub-orbital telescope. • “The SOHO Mission L1 Halo Orbit Recovery From the Attitude Control Anomalies of 1998” (PDF). 4.7 References Retrieved 24 October 2005. - PDF • Sun trek website A useful resource about the Sun [1] “Sungrazing Comets”. U.S. Naval Research Laboratory. Retrieved 2010-09-01. (2,703 discoveries as of 21 April and its eﬀect on the Earth 2014) • Coordinating with SOHO (Stein Vidar Hagfors [2] ESA science missions continue in overtime, ESA, 20 June Haugan. COSPAR Published by Elsevier Ltd. 2013 2004)

[3] “Antenna anomaly may affect SOHO scientific data trans- • SOHO Spots 2000th Comet mission”. ESA news. Retrieved 14 March 2005. • Transits of Objects through the LASCO/C3 field of [4] "SOHO's antenna anomaly: things are much better than view (FOV) in 2013 (Giuseppe Pappa) expected”. ESA news. Retrieved 14 March 2005. • [5] Domingo, V., Fleck, B., Poland, A. I., Solar Physics 162, Notable objects in LASCO C3 and LASCO Star 1-−37 (1995) Maps (identify objects in the field of view for any day of the year) [6] Fleck B (1997). “First Results from SOHO”. Rev Modern Astron. 10: 273–96. Bibcode:1997RvMA...10..273F. • You can discover the next comet...from your couch! [7] Karl Battams on Twitter (16 April 2014). “SOHO comet (science for citizens 18 Oct 2011) discovery rate for 2010-2013”. Retrieved 2014-04-16. • Ceres in LASCO C2 (17 August 2013) [8] Karl Battams on Twitter (2 Jan 2013). “SOHO comet dis- • covery rate for 2010-2012”. Retrieved 2013-01-02. Sunspot Database based on SOHO satellite observations from 1996 to 2011. ( ) [9] SOHO’s 2000th Comet Spotted By Student, SOHO Hot- shots, 28 December 2010 [10] Karl Battams on Twitter (21 April 2014). “SOHO satellite comet discovery count stands at 2,703”. Retrieved 2014- 04-16. [11] Sungrazing Comets (Karl Battams) on Twitter (19 Oct 2012). “has discovered a new comet every 2.59-days on average”. Retrieved 2012-10-20. [12] Mike’s SOHO Comet Hunt [13] http://www.ted.com/talks/erin_mckean_redefines_the_ dictionary.html video time 12:36-13:06 [14] “SOHO Comets 2011”. [15] . “Salil Mulye : 2nd Indian Discoverer of SOHO comet”. Khagol Mandal. 4.9. TEXT AND IMAGE SOURCES, CONTRIBUTORS, AND LICENSES 19

4.9 Text and image sources, contributors, and licenses

4.9.1 Text • Geomagnetic storm Source: http://en.wikipedia.org/wiki/Geomagnetic_storm?oldid=662684721 Contributors: Ed Poor, Stevertigo, Lir, Nealmcb, Michael Hardy, Glenn, Hike395, Wikiborg, Stone, SEWilco, Indefatigable, Denelson83, Twang, Ke4roh, Taliswolf, Tom harri- son, Karn, Everyking, Gilgamesh~enwiki, Dmmaus, Beland, NoPetrol, Paulley, Perey, Kdammers, Vsmith, TerraFrost, Srbauer, RoyBoy, One-dimensional Tangent, MJT1331, Evolauxia, Pearle, Velella, Aurbina, Gene Nygaard, Dejvid, Woohookitty, LOL, Pixeltoo, Rjairam, Eyreland, Wayward, Rjwilmsi, JohnElder, Payo, Chobot, Nylex, YurikBot, Jeffhoy, Hellbus, Hydrargyrum, Shaddack, Salsb, Thane, Nawl- inWiki, Ytcracker, Abune, SmackBot, Speight, Yuyudevil, KVDP, Commander Keane bot, Bluebot, Agateller, Persian Poet Gal, RD- Brown, Rediahs, Colonies Chris, Rlevse, Zvar, Whpq, Jgoulden, Jmnbatista, DinosaursLoveExistence, Mini-Geek, Vgy7ujm, Tazmaniacs, Jaganath, Meco, Mets501, Alan.ca, CapitalR, Tawkerbot2, Cryptic C62, JForget, Runningonbrains, Ruslik0, Michael C Price, Mike1942f, Thijs!bot, Barticus88, RisingStar, Ufwuct, Escarbot, QuiteUnusual, Carolmooredc, Gordonnovak, Magioladitis, LorenzoB, William James Croft, Dbrunner, Info D, Misibacsi, MartinBot, Kiore, Keith D, R'n'B, AstroHurricane001, Personjerry, All Is One, Jesant13, Chiswick Chap, SriMesh, D.M.N., Mokgen, VolkovBot, Philip Trueman, J3gum, Dawaegel, AllGloryToTheHypnotoad, Axpulkki, SieBot, Ste- orra, VVVBot, J-puppy, Dreg, Danoham, StaticGull, Jfromcanada, Martarius, ClueBot, IceUnshattered, Plastikspork, AndersIE, Sv1xv, Djr32, Excirial, Werlebrid44, Muro Bot, Polemos~enwiki, Dthomsen8, Lemchesvej, Starmaker it, Deineka, Addbot, Some jerk on the Internet, Leszek Jańczuk, Sapphosyne, Quantumobserver, Legobot, Luckas-bot, Yobot, Legobot II, Examtester, AnomieBOT, Mauro La- nari, Kokichau, Unara, Kingpin13, Citation bot, Thomas Immel, Leijh, Vertikal Design, RibotBOT, Andyyso, Rainald62, Shadowjams, Omar35880, FrescoBot, Krj373, RicHard-59, Pinethicket, Tom.Reding, EdoDodo, Full-date unlinking bot, Bdescham, EmausBot, John of Reading, Abosalahvimto, Ghostofnemo, Immunize, RA0808, Peaceray, QuantumOfHistory, ZéroBot, Twistoratus, Wikfr, Webbeh, MonoViejo, Anonimski, ChuispastonBot, RockMagnetist, ClueBot NG, Ruckgerm, Flynx, Lynnbwilsoniii, Helpful Pixie Bot, HMSSolent, Bibcode Bot, Richfj, BG19bot, Vagobot, McQuade, Shawn Worthington Laser Plasma, BattyBot, Khazar2, Evaraseac, Bnland, Ultra Ve- nia, Makecat-bot, Jsimmms002, CeeCeeM, Pokebub22, Marc Bago, Monkbot, Bharding512, Bentank, Perapin, Tetra quark, KasparBot and Anonymous: 133 • Solar storm of 1859 Source: http://en.wikipedia.org/wiki/Solar_storm_of_1859?oldid=663799273 Contributors: Ed Poor, Nealmcb, William M. Connolley, Glenn, Rl, Timwi, Sanxiyn, Angmering, Peter Ellis, Simplicius, Urhixidur, Discospinster, Rich Farmbrough, Smyth, TerraFrost, RoyBoy, Causa sui, Evolauxia, Grutness, Eli the Bearded, KevinOKeeffe, GregorB, Graham87, Drbogdan, Rjwilmsi, Veg- aswikian, Jehochman, Spencerk, GusF, Hydrargyrum, Grafen, Effco, Lacunae, Rfsmit, SmackBot, McGeddon, Kintetsubuffalo, Skizzik, RDBrown, Kscheffler, Colonies Chris, Yaf, JRPG, Rrburke, DinosaursLoveExistence, Zaxius, John, SilkTork, Diverman, IronGargoyle, A. Parrot, Rkmlai, Janus303, Daggerstab, Ruslik0, Danrok, Electron9, Nick Number, Widefox, Arch dude, Max Hyre, Kq6up, Nick Cooper, Presearch, Gabriel Kielland, Diotime, Pharaoh of the Wizards, Extransit, OriEri, DeFaultRyan, Pdcook, Speciate, Hugo999, W. B. Wilson, Teledildonix314, TXiKiBoT, CMBJ, Regregex, SieBot, Sonicology, Hertz1888, Wilson44691, Martyvis, Mimihitam, Jdaloner, Brylie, Martarius, Wikiwhatnot, Gene93k, Deanlaw, Mild Bill Hiccup, Niceguyedc, TarzanASG, Cirt, Jusdafax, NuclearWarfare, PCHS- NJROTC, Mitch Ames, Addbot, RTG, Roux, Luckas-bot, KamikazeBot, ArthurBot, Xqbot, DSisyphBot, Polemyx, X5dna, Fotaun, Lucien- BOT, Belzarek, Citation bot 1, Pinethicket, Tom.Reding, AmphBot, Geogene, Jaxdelaguerre, MrX, Ripchip Bot, Nmillerche, EmausBot, Primefac, ZéroBot, Suslindisambiguator, Wingman4l7, Kristoffer L, Anonimski, ChuispastonBot, RockMagnetist, Terraflorin, ClueBot NG, RaptorHunter, Mpkilla, CopperSquare, Helpful Pixie Bot, Lolm8, Gob Lofa, Bibcode Bot, BG19bot, NewsAndEventsGuy, Tony Tan, Joshtaco, Andyhowlett, Bluefish1111, Akinawashington, Kogge, 22merlin, Monkbot, NCCL2310 and Anonymous: 87 • March 1989 geomagnetic storm Source: http://en.wikipedia.org/wiki/March_1989_geomagnetic_storm?oldid=665125882 Contributors: Ed Poor, Edward, Greenman, Docu, Vsmith, Evolauxia, Zarateman, Velella, Vegaswikian, Nihiltres, Spencerk, Theredstarswl, Lacunae, Arthur Rubin, Xetheare, Benandorsqueaks, SmackBot, Grandmartin11, Squiddy, Chris the speller, DinosaursLoveExistence, John, Iron- Gargoyle, Sinistrum, Jsorens, VoxLuna, Ruslik0, Cydebot, Tec15, Mtpaley, Gimmetrow, Bouchecl, Widefox, CZmarlin, The penfool, Gabriel Kielland, Hugo999, Scottywong, CMBJ, Crash Underride, Danoham, Twinsday, Martarius, Chuckwik, Istas, Dthomsen8, Myst- Bot, Addbot, Luckas-bot, Yobot, AnomieBOT, 6th Happiness, JayJay, FrescoBot, Shirenomad, Vrenator, Lucien504, ZéroBot, Cogiati, H3llBot, Noggo, LineChaser, Terraflorin, ClueBot NG, RaptorHunter, Gob Lofa, Billie usagi, BattyBot, Brome875 and Anonymous: 31 • Solar and Heliospheric Observatory Source: http://en.wikipedia.org/wiki/Solar_and_Heliospheric_Observatory?oldid=664382185 Contributors: Vicki Rosenzweig, Bryan Derksen, The Anome, SimonP, JDG, Patrick, Infrogmation, Looxix~enwiki, Ahoerstemeier, Angela, Andrewa, Marteau, Brammeke, Smack, Timwi, Stone, Ed g2s, Vaceituno, Pakaran, Jamesday, Denelson83, Robbot, Astronau- tics~enwiki, Zandperl, Wereon, Alan Liefting, Matt Gies, Curps, Wikibob, Bobblewik, Junkyardprince, Keith Edkins, Geni, Beland, Mel- loss, Urhixidur, Hellisp, Zowie, Wuzzeb, RJHall, Huntster, Susvolans, Hooperbloob, Michael Drüing, Axl, PAR, Wdfarmer, Snowolf, Drbreznjev, Nick Mks, Gmaxwell, Jeffrey O. Gustafson, -Ril-, CharlesC, M100, Rnt20, Drbogdan, Rjwilmsi, Tim!, Eyu100, Mike Peel, FlaBot, Philip Scherrer, Ground Zero, Chobot, DVdm, Whosasking, YurikBot, Wavelength, Swerty, Freiberg, SnoopY~enwiki, Epolk, Gaius Cornelius, Sanguinity, SEWilcoBot, DarthVader, Tony1, Adreamsoul, Chesnok, Reyk, Esprit15d, Argo Navis, GrinBot~enwiki, That Guy, From That Show!, Sardanaphalus, SmackBot, Unyoyega, Nickst, Gilliam, Bluebot, I7s, Hibernian, Redline, WDGraham, OrphanBot, Ryan Roos, SashatoBot, Tazmaniacs, JorisvS, Minna Sora no Shita, Pierre cb, Xiaphias, Geologyguy, RockinRob, CmdrObot, ThreeBlind- Mice, Cydebot, Renamed user 1253, Paddles, Thijs!bot, Mbell, Ricnun, Movses, Myanw, Planetary, Arch dude, Magioladitis, Dmoulton, Wiki.user, Swpb, Soulbot, Kheider, MartinBot, Schmloof, R'n'B, CommonsDelinker, Eeric, J.delanoy, AstroHurricane001, Adavidb, Silas S. Brown, Ohms law, Atropos235, Pry45, Idioma-bot, Funandtrvl, VolkovBot, Sdsds, SieBot, YonaBot, Kasos fr, Murlough23, Fratrep, Dravecky, MBK004, Sabolish, Roadcrusher3, Coinmanj, MrBn, SoxBot III, Kbdankbot, Addbot, DOI bot, OliverTwisted, Pscherrer, De- bresser, Zorrobot, Luckas-bot, Yobot, Fraggle81, Aldebaran66, Mauro Lanari, Jim1138, Citation bot, Marshallsumter, Xqbot, Nasa-verve, Hauganm, Teukros, Smallman12q, Misbeliever, Fotaun, FrescoBot, 117Avenue, Jonesey95, Tom.Reding, SpaceFlight89, Fabian Elleder, Trappist the monk, Puzl bustr, RjwilmsiBot, EmausBot, SkywalkerPL, ClueBot NG, Lynnbwilsoniii, Gob Lofa, BG19bot, KlausWilhelm, Aisteco, Jaybear, GoShow, Khazar2, Lugia2453, GabeIglesia, Salilmulye, Sandy119, Monkbot, BethNaught, Rumantchs, Tetra quark, Norbert81, Sunman42 and Anonymous: 74

4.9.2 Images • File:Carrington_Richard_sunspots_1859.jpg Source: https://upload.wikimedia.org/wikipedia/commons/e/e5/Carrington_Richard_ sunspots_1859.jpg License: Public domain Contributors: Page 540 of the Nov-Dec, 2007 issue of American Scientist (volume 95) Original artist: Richard Carrington 20 CHAPTER 4. SOLAR AND HELIOSPHERIC OBSERVATORY

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