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2 Space Weather Impacts in Retrospect
Pages 16-28

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From page 16...
... , who opened the session with an overview of the principal kinds of space weather disturbances and illustrated their effects on modern technological systems with examples that included the wellknown Quebec blackout during the magnetic superstorm of March 1989 and the disruption of the Anik communications satellites in 1994, as well as some less well known events such as the disruption of Allied radars in 1942 by an intense solar outburst and the brief high-frequency communication outage experienced by Air Force One en route to China during a solar event in 1984. She ended her talk with a comparison of the magnitude of historical solar energetic particle (SEP)
From page 17...
... Because electricity is critical to maintaining modern lifestyles, the consumer surplus from electricity is generally believed to be very large relative to expenditures. As a result, interruptions in electricity supply are believed to be very costly in terms of lost consumer surplus.
From page 18...
... In Koza's opinion, the power system is more vulnerable to a severe geomagnetic storm during a period of light load with unusually heavy transfer patterns, as is prevalent in the middle of the night during the spring and the fall. Loss of multiple facilities at lighter loads, and high levels of long-distance transfers between low-cost but more distant generating plants and load centers, set up the potential for voltage collapse with minimal ability for mitigation.
From page 19...
... Koza indicated that the forecasts were invaluable, namely that their value warranted a ranking of 10 out of 10. One of the committee members noted that Koza's assessment of increased power grid vulnerability during the spring and the fall was troubling given the well-documented evidence6 that major space weather events are more likely during the spring and fall (Figure 2.3)
From page 20...
... 20 SEVERE SPACE WEATHER EVENTS -- UNDERSTANDING SOCIETAL AND ECONOMIC IMPACTS 120 Number of Events Classified as Kp8 or Kp9 100 80 60 40 20 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month FIGURE 2.3  Incidence of Kp8/Kp9 events by month, 1932-2007, based on an analysis of 222,072 observations. SOURCE: Data from World Data Center for Geomagnetism.
From page 21...
... This model takes the three-dimensional ionosphere FIGURE 2.5  The WAAS architecture. SOURCE: Leo Eldredge, Federal Aviation Administration, "Space Weather Impacts on 2.5 Eldredge.eps the Wide Area Augmentation System (WAAS)
From page 22...
... In this situation, integrity, or assured accuracy, is not available in the affected areas, and WAAS can only be used for two-dimensional guidance for a nonprecision approach and landing in these regions throughout the duration of the ionospheric disturbance. Eldredge noted that because of the thin shell model's vulnerability, space weather "presents the largest limitation to vertically guided service." While horizontal navigation guidance was continuously available, vertical navigation guidance was unavailable for approximately 30 hours during the three to four large geomagnetic storms experienced in October 2003.
From page 23...
... SOURCE: Leo Eldredge, bitmap Federal Aviation Administration, "Space Weather Impacts on the Wide Area Augmentation System (WAAS) ," presentation to the space weather workshop, May 22, 2008.
From page 24...
... Bodeau stressed that access to space weather data is critical to finding the cause of anomalies and failures, which is the first step in making satellites more resistant to space weather events. Bodeau indicated that there have been numerous studies correlating satellite anomalies with space weather.
From page 25...
... that occur episodically around solar maximum. Of major concern to the spacecraft industry are the periodic enhancements of the magnetospheric energetic electron environment associated with high-speed solar wind streams emanating from coronal holes during the declining phase of the solar cycle (see Figure 5.13)
From page 26...
... However, high-rate and real-time GPS analysis is rapidly improving in detecting seismic surface waves and co-seismic displacement,13,14,15 and brief or partial loss of tracking because of space weather during a critical event could certainly degrade applications with societal and economic impacts, such as tsunami warning systems. During the subsequent question-and-answer session, Moore was asked about the value of space weather forecasts.
From page 27...
... 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.
From page 28...
... Gendt, The International GPS Service (IGS) : Celebrating the 10th anniversary and looking to the next decade, Adv.


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