Study on Revision to NOAA's Space Weather Scales

The U.S. National Oceanic and Atmospheric Administration (NOAA) introduced the Space Weather Scales in 1999 to communicate expected space weather conditions and their possible effects on people and systems. The scales characterize geomagnetic storms, solar proton radiation storms, and solar flare x-ray emissions, each of which can imperil physical infrastructure, assets, and human health. The aviation, electric utilities, and satellite operations sectors, among others, depend on timely and accurate space weather products based on the Space Weather Scales. The Space Weather Scales trigger actions and initiate hazard preparedness and mitigation operations. Since 1999, the Space Weather Scales have remained unchanged despite rapid growth in the size and needs of the user community. The growth of traditional users and emergence of new users of space weather hazard communication has revealed gaps and shortcomings in the Space Weather Scales.

Society’s increased reliance on systems that can be affected by space weather warrants a careful consideration of the revision and improvement of space weather hazard communications, including the Space Weather Scales. Space weather hazards are often global and require strong international coordination of standards for measurement and communication. The transboundary nature of space weather hazards, along with the wide-spread adoption of Space Weather Scales by the international community, suggests that any revision to Space Weather Scales should occur in partnership with key commercial sector and international stakeholders.

On behalf of the NOAA Space Weather Prediction Center (SWPC), the IDA Science and Technology Policy Institute (STPI) conducted research and analyses on the use of Space Weather Scales to guide NOAA’s review and potential revision of the Space Weather Scales. STPI conducted interviews, facilitated workshops, administered surveys, and analyzed request for information data from the public, private, academic, U.S. government, and non-governmental organization communities. This included input from key stakeholders in the international space weather community and different space weather hazard communication user sectors, such as aviation and emergency management.

In this paper, we will discuss our research methodology and findings. The findings are organized by the current scales (G-Scale, S-Scale, R-Scale) as well as input from the community on potential new scales and considers the multitude of minor and major revisions that could improve the effectiveness of the scales and space weather hazard communication.