A Policy Statement of the American Meteorological Society
(Adopted by AMS Council on 9 July 2013)
SPACE WEATHER DEFINITION. Space weather refers to the dynamic conditions on the Sun and in the space environment, in particular, in the near-Earth environment.
SOCIETAL IMPACTS OF SPACE WEATHER. As our dependence on complex, advanced technology increases, so does our vulnerability to space weather. Space weather is a global-scale phenomenon with the demonstrated ability to disrupt high-frequency radio signals, satellite-based communications, navigational satellite positioning and timing signals, spacecraft operations, and electric power delivery with cascading socioeconomic effects resulting from these disruptions. Space weather can also present an increased health risk for astronauts and well as aviation flight crews and passengers on transpolar flights. The estimated cost of an extreme space weather storm could reach up to a trillion dollars with a potential recovery time of 4–10 years.1
An extreme space weather storm is a low-probability, high-consequence event that poses risks to critical infrastructures around the world. Unlike with almost all other natural hazards, modern society lacks adequate experience in preparing for, and responding to, an extreme space weather storm. This situation is exacerbated by our heavy reliance on space-based technologies and the rapidly evolving nature of our vulnerability. A storm that degrades the electric power grid could affect not only the energy sector, but also the transportation, manufacturing, communications, banking, and finance sectors, as well as government services and emergency response capabilities.
Space weather can also impact the operation of critical infrastructure relying on space-based assets. Space weather storms can distort and disrupt signals emitted by Global Positioning System (GPS) satellites. GPS boosts productivity across many sectors of the economy, including farming, construction, mining, surveying, and a wide variety of transportation and delivery systems. Major communications networks, banking systems, financial markets, and power grids rely on GPS for precise time synchronization. These storms also degrade service from communication satellites and have triggered permanent damage to these high-value assets.
Space weather activity, while more pronounced near solar maximum— the peak of the 11-year sunspot cycle—can occur at any time; geomagnetic storms can be especially severe during the decline of the solar cycle. Many technological industries routinely take action based on space weather information in order to mitigate adverse impacts.
PREDICTING SPACE WEATHER. Industries vital to the U.S. and the global economy depend on space weather predictions for maintaining the integrity and safety of their activities. Compared with meteorology, space weather predictions suffer from both a lack of observations and limitations of even the best available space weather models to describe the complex phenomena involved. While space weather–related research and technologies are showing great promise for improving forecasts, most responses to space weather are based on current conditions, with limited advance notice. Improved space weather predictions are required to enable users and operators to develop appropriate space weather–related policies and protective measures in advance. Such actions will also help to minimize the time required to recover from any infrastructure disruption. Investments by the U.S. and the global community in space weather-related research and technologies require a sustained national commitment to improve space weather prediction capability.
RECOMMENDATIONS. The American Meteorological Society (AMS), in recognition of the importance of space weather research and services and the need to develop advanced forecasting and mitigation techniques, strongly recommends the following:
1. National Research Council, Space Studies Board, 2008: Severe Space Weather Events—Understanding Societal and Economic Impacts, The National Academies Press, 144pp.