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SOHO solar image
SOHO 284 Angstrom image of the Sun, probing the upper atmosphere at 2 million degrees. (credit: NASA)

The trillion-dollar (solar) storm

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Space weather events such as solar flares, the ejection of energetic particles from the Sun, and geomagnetic disturbances, can have measurable detrimental impacts on satellite operations, the ubiquitous Global Positioning System (GPS), high-frequency (HF) airplane communications, navigation, aviation, and the electrical power grid. These disruptions can have ripple effects, so that even economic sectors that are not ostensibly dependent on space assets (e.g. financial services) can suffer losses.

As the United States’ economic and national security becomes more dependent on space-borne assets and its aging power grid becomes more susceptible to cascading failures, the impact of space weather events will continue to grow.

Even with satellite observations, the advanced notification of space weather events as provided by the Space Weather Prediction Center (SWPC), run by the National Oceanic and Atmospheric Administration (NOAA), can range from days to mere minutes. Although major disruptions are predicted to occur only once a century, significant impacts, with extended local outages and disruptions, occur once a decade. Minor events, resulting in aircraft re-routing and short-term GPS disruptions, for example, occur almost yearly.

As the United States’ economic and national security becomes more dependent on space-borne assets and its aging power grid becomes more susceptible to cascading failures, the impact of space weather events will continue to grow. Furthermore, unlike individual component failures, space weather events induce failures in entire groups of assets, so that shifting demand, such as re-routing communication traffic from one satellite to another or power from one transformer to another, will be of limited use. While meetings, such as NOAA's annual Space Weather Workshop (SWW), discuss the issue, limited national resources have been allocated to prepare for a major space weather event. This report enumerates the current activities of different agencies that are exploring how the United States can become more resilient to space weather events in the future.

The Sun regularly produces storms of enormous magnitudes that flood the solar system with energetic debris. The Solar and Heliospheric Observatory (SOHO), a joint ESA and NASA mission, is one of a number of satellites that monitor the sun in real time.1 Sometimes, the energetic detritus from these storms intercepts the orbit of the Earth. High energy photons, such as X-rays from a solar flare, can ionize the Earth’s upper atmosphere, severely interfering with radio communication and GPS satellites. Unprotected astronauts in space could be exposed to dangerous radiation exposure. Slower-moving particles from a solar storm can form a coronal mass ejection (CME) that can reach the Earth in several days or even hours. These particles can impact the Earth’s magnetic field, producing strong electromagnetic fluctuations on the ground, too. These fluctuations, in turn, can produce powerful electric currents through natural rock, power lines, and pipelines. These currents can be strong enough to blow out large power transformers, resulting in widespread blackouts and phone and Internet communication failures. Replacing a large power transformer can take months or even years, so these outages could last for a significant time.

The first known modern occurrence of such a solar storm impacting the Earth was the Carrington Event in 1859.2 Richard Carrington observed a large flare on the Sun. Then, the next day, auroras could be seen in tropical latitudes and telegraph systems all over the world, starting to shock telegraph operators, operating while unplugged, and igniting the telegraph paper.3 In March 1989, a solar storm significantly smaller than the Carrington Event resulted in a nine-hour power outage for six million people in Canada.4 Other Carrington-level events have been observed in approximately the last 150 years, such as the super-flare observed on November 4, 2003,5 so there is no expectation that the Carrington Event was a unique event.

In May of 1967, a solar storm brought the world to the brink of nuclear war due to disruption of high-frequency communication across the polar cap.

Most events have not resulted in CMEs impacting the Earth. However, in May 1921, a storm approximately as strong as the Carrington Event hit the Earth, causing similar damage to telegraph facilities. If the Carrington Event or the 1921 storm happened again today, the damage is estimated to be well over $1 trillion,6 as many millions of people would be without power or communications for months or even years. In July 2012, a large CME, estimated to be even more severe than the CME from the Carrington event,7 barely missed impacting the Earth. If it had hit the Earth, the damage would have been so severe that, according to experts, “we would still be picking up the pieces.”8 This storm was important in that it missed Earth but impacted STEREO-A, a probe designed to measure such events. By being outside the Earth’s magnetosphere, the probe survived the storm and provided, for the first time, detailed data on the shockwaves and energetic particles produced by a major solar storm.

In October 2003, a moderate-size CME forced astronauts on the International Space Station (ISS) to take shelter from the increased radiation, caused diversions in polar region airline flights, degraded GPS performance, caused a Japanese satellite failure, and induced power outages in Europe9 and Africa.10 In January 2005, a relatively minor space weather event caused the degradation of the HF radio communications of transpolar airline travel, resulting in the rerouting of dozens of flights and subsequent reduction in cargo capacity.11 In November 2015, a similar solar event affected radar stations in Sweden, putting air traffic control off-line for about an hour.12

At the peak of solar cycle 23 in March 2002, during Operation Anaconda in Afghanistan, ionospheric variability hampered UHF communications. The miscommunications resulted in an intense firefight that left seven Americans dead.13 In May of 1967, a solar storm brought the world to the brink of nuclear war due to disruption of high-frequency communication across the polar cap.14 This was at the height of the Cold War, and the United States interpreted the radio disruption as jamming by the Soviet Union. Only the fledgling Air Force space weather forecasting group was able to connect the disruption with an energetic solar event and prevent escalation. Although this storm did not result in large geomagnetically induced currents, today’s cell phone and GPS systems would have been significantly impacted by such a storm today.

It is important to note that, unlike atmospheric storms such as hurricanes, the theoretical intensity limits of space weather events is unknown. That is, events much stronger than the 1859 Carrington Event, or even the July 2012 “near-miss,” may be possible. Thus, the United States is in a race against time to beef up its power and communication infrastructure before the next “trillion-dollar storm” hits. For example, GPS can be made more resilient to geomagnetic storm effects with improved codes and frequencies. Improved forecasting of events could permit the off-lining of sensitive hardware, resulting in short-term power outages rather than month-long outages. Present-day spacecraft such as SOHO, STEREO, ACE, DSCOVR, and Wind are intended to study the underlying physics of flares, CMEs, and geomagnetic storms in order to improve NOAA’s SWPC forecasts, but spacecraft located closer to the Sun than the Sun-Earth L-1 point could significantly improve warning times for some events.

Beginning with a National Academies of Science (NAS) committee report in 1979,15 the importance and relevance of space weather has been discussed at the national level. The 1989 space weather event induced a Quebec power outage that resulted in impacts as far-reaching as the failure of a large power transformer in New Jersey, showing there could be large regional cascading impacts. Therefore, by the early 1990s, NOAA and the US Air Force started providing space weather support services. In 1994, the National Space Weather Program (NSWP) was formed at the federal level to form a strategic plan to study space weather.16 Due to the breadth of the topic, the NSWP evolved to include a large number of agencies such as NASA, NOAA, the Defense Department, the US Air Force, the US Geological Survey, NSF, FAA, the Department of Energy, the Department of Homeland Security, and FEMA.

The NSWP studies also made it clear that a Carrington-level event will happen again—it is only a question of when.

Coordinating the efforts of these agencies, the NSWP was instrumental in establishing NOAA’s Space Environment Center (SEC), which provides space weather forecasts to this day under the SWPC label. Through NOAA’s annual SWW, the NSWP continued to raise the visibility of space weather issues at the national level. For example, the North American Electric Reliability Corporation (NERC) hosted a Geomagnetic Disturbance (GMD) Workshop in 2011,17 establishing an alert system to prepare and mitigate the GMD impacts to the planning and operations of power companies. Further NSWP studies helped provide the foundation for agreements that have resulted in critical space weather monitoring missions, such as COSMIC-2 and DSCOVR.

The NSWP studies also made it clear that a Carrington-level event will happen again—it is only a question of when. By analyzing solar storm records dating back more than 50 years, a 2014 report concluded that there is a 12 percent chance of Earth being hit by a Carrington-class storm within a decade.18 This statistic helped lead to the “Fixing America’s Surface Transportation Act” that established a strategic reserve of spare large power transformers.19 By 2010, even the insurance industry was taking note of space weather issues, with a report by the Lloyds Company agreeing with the severity of the issue and estimating a return period of 50 years for a Quebec-level event.20 Most at risk are regions such as the US East Coast, where cascading failures of transformers serving highly populated areas could create a prolonged power outage.

In 2011, relevant industry leaders, after meetings at the SWW, formed the American Commercial Space Weather Association (ACSWA) to identify technology gaps that could be filled by private action. In 2014, the establishment of the Space Weather Operations, Research, and Mitigation (SWORM) Task Force provided the National Science and Technology Council (NSTC) oversight over the NSWP. The NSWP, before being deactivated in 2015, provided SWORM with vital input in developing a National Space Weather Strategy (NSWS)21 and Space Weather Action Plan (SWAP)22 that was released in October 2015.23 These activities have resulted in cooperation between academia, industry, international partners, and more than 20 diverse government agencies to amass data and models on how to deal with a Carrington-level Event.

The goals of the NSWS are to establish benchmarks for space weather events; enhance response and recovery capabilities; improve protection and mitigation efforts; improve assessment, modeling, and prediction of impacts on critical infrastructure; improve space weather services through advancing understanding and forecasting; and increase international cooperation. The SWAP identifies approximately 100 activities with associated deliverables and timelines to achieve the goals identified in the NSWS. The SWAP assigns each activity to at least one federal agency and emphasizes the need for collaboration with industry, academia, and other nations. SWORM was given an unfunded mandate to carry out these activities and thus achieve the goals of NSWS. As of June 2017, 80 percent of these activities have been completed.

In addition to the SWW, a variety of meetings in recent years have been held in order to bring the space weather community together. The American Meteorological Society occasionally holds Space Weather Conferences, with the latest in 2016. The international Committee on Space Research (COSPAR) hosted a SW Roadmap meeting in India in 2016. This enhanced visibility of space weather issues, combined with the “near-miss” of 2012, got the attention of the White House, resulting in the signing of an October 2016 executive order intended to begin officially coordinating national efforts to prepare for a major space weather event.

So far, space weather has been an ideal example of how the federal government should approach complex, far-reaching issues—it is now up to the new administration to follow through.

Furthermore, on May 2, 2017, the Senate passed the “Space Weather Research and Forecasting Act,”24 the first bill specifically focusing on space weather issues; a nearly identical bill, H.R. 3086, was introduced in the House on June 27, 2017, where it is expected to pass as well. The bills essentially codify much of the NSWS and SWAP, giving those activities the weight of a congressional mandate. For example, it directs the National Science and Technology Council (NSTC) to establish a Space Weather Interagency Working Group (SWIWG), coordinated by the Office of Science Technology and Policy (OSTP), with the primary goal of establishing cross-agency benchmarks defining space weather events. However, it is an authorization bill, not an appropriations bill, so funds are not allocated to achieve the stated goals of improving the nation’s ability to “prepare, avoid, mitigate, respond to, and recover from potentially devastating impacts of space weather events.”

Building upon the work of the NSWP and SWORM, the SWIWG should be able to publish final benchmarks within 18 months as required by the bill, but it is up to the new administration to follow up on this by providing funding to implement the activities called out in the SWAP. However, the proposed fiscal year 2018 budget calls for the elimination of the USGS geomagnetism program that monitors changes in Earth’s magnetic field, providing data that help NOAA and the USAF track magnetic storms.25

So far, space weather has been an ideal example of how the federal government should approach complex, far-reaching issues—it is now up to the new administration to follow through with the next steps before the “near-miss” event of 2012 becomes a reality.


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  2. R.-C. Carrington, “Description of a Singular Appearance seen in the Sun on September 1, 1859,” Monthly Notices of the Royal Astronomical Society 20 (1859), 13-15.
  3. M.A. Shea & D.F. Smart, “Compendium of the eight articles on the ‘`Carrington Event` attributed to or written by Elias Loomis in the American Journal of Science, 1859–1861”, Adv. Space Res., 38 (2006) 313–385.
  4. “March 13, 1989 Geomagnetic Disturbance”.
  5. “Biggest ever solar flare was even bigger than thought”, American Geophysical Union, March 15, 2004.
  6. Severe Space Weather Events: Understanding Societal and Economic Impacts: A workshop Report (2008).
  7. Baker, et al., “A major solar eruptive event in July 2012”, Space Weather, 11 (2013), 585-591.
  8. Near Miss: The Solar Superstorm of July 2012.
  9. R. J. Pirjola & D. H. Boteler,“Geomagnetically Induced Currents in European High-Voltage Power Systems”, CCECE. 1263-1266, May 2006.
  10. Makhosi, T., G. Coetzee, “GENERATOR TRANSFORMER DAMAGE IN ESKOM NETWORK”, EPRI Workshop on Transformers and Geomagnetic Currents, Washington DC, Sept 23, 2004.
  11. Lloyd’s 360° Risk Insight Briefing: Space Weather, July 8, 2011.
  12. Solar storm knocks out flight control systems in Sweden.
  13. M.A. Kelly, et al., “Progress toward forecasting of space weather effects on UHF SATCOM after Operation Anaconda”, Space Weather, 12 (2014), 601-611.
  14. D.J. Knipp, et. al, “The May 1967 great storm and radio disruption event: Extreme space weather and extraordinary responses”, Space Weather, 14 (2016), 614-533.
  15. Space Plasma Physics: The Study of Solar-System Plasmas.
  16. M. Bonadonna et al, “The National Space Weather Program: Two decades of interagency partnership and accomplishments”, Space Weather, 15 (2017), 4-25.
  17. Geo-Magnetic Disturbances (GMD): Monitoring, Mitigation, and Next Steps.
  18. P. Riley, "On the probability of occurrence of extreme space weather events.", Space Weather 10 (2012), SO2012.
  19. Fixing America’s Surface Transportation Act.
  20. Solar Storm Risk to the North American Electric Grid.
  21. A National Space Weather Strategy.
  23. S. Jonas & E.D. McCarron, “White House Releases National Space Weather Strategy and Action Plan”, Space Weather, 14 (2016), 54-55.
  24. S. 141: Space Weather Research and Forecasting Act.
  25. “Trump’s proposed 2018 budget takes an ax to science research funding”.