NOAA Space Weather Prediction Center Radiation Advisories for the International Civil Aviation Organization

• Published in: Space weather Vol. 21; no. 7
• Main Authors: Bain, H. M., Copeland, K., Onsager, T. G., Steenburgh, R. A.
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 01.07.2023
• Subjects: Aviation; Civil aviation; Energetic particles; Flight; forecasting; Format; GOES satellites; Latitude; Modelling; operational; Particle intensity; Polar regions; Radiation; Regulatory agencies; Satellites; Solar activity; Solar radiation; Southern Hemisphere; Space weather; Storms; users; Weather forecasting; United States > US
• ISSN: 1542-7390; 1539-4964; 1542-7390
• DOI: 10.1029/2022SW003346

The National Oceanic and Atmospheric Administration's Space Weather Prediction Center (NOAA/SWPC) issues several solar radiation storm products: the long standing proton Warnings and Alerts that are based on particle intensity levels observed by the Geostationary Operational Environmental Satellites; and the more recent International Civil Aviation Organization (ICAO) radiation advisories which specify effective dose rates at aviation flight levels. SWPC ICAO advisories are supported by the U.S. Federal Aviation Administration (FAA) CARI‐7A model. In this paper we use CARI‐7A modeling results for the Ground Level Enhancement 69 (GLE69) solar radiation storm which occurred on the 20th of January 2005 to demonstrate the ICAO advisory format. For the onset and peak of GLE69, we find that a severe (SEV) radiation advisory would have been issued for altitudes above 32,000 ft, for polar and mid latitude regions of the northern and southern hemisphere. At lower altitudes, down to 25,000 ft, the moderate (MOD) radiation threshold would have been exceeded. In total, 10 ICAO radiation advisories would have been issued over 6.5 hr. From the retrospective modeling of GLE69, and feedback from users, we identify ways in which the ICAO advisories should be improved. Plain Language Summary The National Oceanic and Atmospheric Administration's Space Weather Prediction Center (NOAA/SWPC) issues products related to solar radiation storms, defined as periods when the number of energetic particles in space are elevated because of enhanced solar activity. Traditionally these products have been based on observations by NOAA's Geostationary Operational Environmental Satellite, indicating the intensity of the storm outside the Earth's atmosphere. New advisories for the International Civil Aviation Organization (ICAO) alert operators when the radiation environment at aviation flight levels is enhanced. At SWPC, ICAO radiation advisories are supported by the U.S. Federal Aviation Administration CARI‐7A model. We present CARI‐7A modeling results for a solar radiation storm which occurred on the 20th of January 2005. At the peak of the storm, we find that radiation advisories would have been issued down to 25,000 ft, for polar and mid latitude regions of the northern and southern hemisphere. The issued advisories would have been updated periodically to keep forecast users informed as to which flight levels were impacted. In total, SWPC would have been issuing ICAO radiation advisories for 6.5 hr. The results identify several ways in which the ICAO advisory format could be improved to prevent people receiving unnecessary warnings. Key Points Radiation advisories for the International Civil Aviation Organization (ICAO) provide regional information for users During GLE69 the ICAO SEVERE radiation threshold was exceeded in the polar and mid latitude bands down to 32,000 ft Based on the current format, large geographic regions are likely to receive unnecessary ICAO radiation advisories