system, a key infrastructure in which interruptions in supply can have major economic consequences. Specifically, the March 1989 geomagnetic space storm resulted in a major blackout in the Hydro-Quebec power grid and also contributed to power grid anomalies throughout North America. In the opinion of Frank Koza of PJM Interconnection, power grids such as PJM are most vulnerable to space weather during periods of light load with unusually heavy electricity flows from generating plants to load centers, as is prevalent in the middle of the night during the spring and the fall. This assessment of increased power grid vulnerability during the spring and the fall was found to be troubling given the well-documented evidence that major space weather events are more likely during the spring and fall. Given this coincidence between power grid vulnerability and the incidence of major space weather events, it was not surprising that Koza indicated that PJM places a high value on space weather forecasts.

Evidence was also presented that space weather has impaired the provision of GPS. One notable example was the FAA’s inability to provide its GPS-augmented vertical aviation navigation guidance for approximately 30 hours during the large geomagnetic storms in late October 2003. This vulnerability is expected to persist over the next decade. The value of improved space weather forecasting may be less significant in this case than with respect to electric power, since aviation safety can be maintained by increasing vertical separation standards. However, there may be considerable interest by airlines and passengers in forecasts of severe space weather events because of the impact of these events on the capacity of the aviation navigation system. Among the important societal applications of GPS, Angelyn Moore noted that high-rate and real-time GPS analysis is rapidly improving in detecting seismic activity, which in turn can have applications for tsunami warnings.

This workshop session also provided an overview of the economic value of services provided by satellites and how the provision of those services can be threatened by adverse space weather conditions. Michael Bodeau of Northrop Grumman indicated that numerous studies have correlated satellite anomalies with space weather. Specifically, more than half the anomalies experienced in 2003 occurred during the large geomagnetic storms in late October 2003. The economic impacts of these anomalies have ranged from minor to highly significant depending on the nature of the impact and whether substitute services were available. The value of improved space weather forecasts is dependent on the nature of the satellite service and the extent to which operators can mitigate the potential damage to a satellite by changing operations.



1. For more information about the concept of consumer surplus, see N.G. Mankiw, Principles of Microeconomics, Fourth Edition, 2007, pp. 138-142.


2. de Nooij, M., C.C. Koopmans, and C.C. Bijvoet, The value of supply security: The costs of power interruptions: Economic input for damage reduction and investment in networks, Energy Economics 29(2), 277-295, 2007.


3. See


4. Electricity Consumers Resource Council, The economic impacts of the August 2003 blackout, 2004, available at


5. This estimate is based on forecasted load and day-ahead reference prices.


6. For example, C.T. Russell and R.L. McPherron, Semiannual variation of geomagnetic activity, J. Geophys. Res. 78, 92-108, 1973.


7. Office of Aviation Policy and Plans, FAA Long-Range Aerospace Forecasts: Fiscal Years 2020, 2025, and 2030, September 2007, p. 10.


8. The glide path of a descending airplane passes through a “decision height” at which the pilot must decide to abort or complete the landing. Category I precision conditions exist when the decision height is 200 feet or above and the runway visual range is 2400 feet or greater.


9. Bedingfield, K.L., R.D. Leach, and M.B. Alexander, Spacecraft System Failures and Anomalies Attributed to the Natural Space Environment, NASA Reference Publication 1390, August 2006, pp. 1 and 5.


10. Encounters with high-speed streams recur approximately every 27 days during the declining phase of the solar cycle, corresponding to the rotation period of the Sun. The geomagnetic disturbances associated with them are referred to as “recurrent” geomagnetic storms, which differ from CME-driven storms in both their cause and phenomenology. See J.E. Borovsky and M.H. Denton, Differences between CME-driven storms and CIR-driven storms, J. Geophys. Res. 111, A07S08, 2006, doi:10.1029/2005JA011447. Instruments in space and on the ground monitor the substorm and energetic electron environments,

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