The Influence Of Solar Activity On High-Frequency Communications: A Systemic Risk To Global Communication

Radio blackouts, phenomena resulting from the interaction between solar activity and the Earth's ionosphere, constitute an invisible and underestimated societal risk with significant potential to impact High-Frequency (HF) communications. Such communications are vital for the safety and operation of aircraft, maritime vessels, broadcasting systems, emergency services, and amateur radio networks. This study was conducted by seventh-grade elementary school students from a public school in Santa Catarina, Brazil, as a research project within the Civil Defense in Schools Program. Its objective was to record the frequency and intensity of radio blackouts, aiming to assess the viability of a low-cost approach for Disaster Risk Reduction (DRR) education by integrating space weather risks into the educational environment. The methodology employed consisted of data collection from May to December 2025 using the Space Weather application. Data were recorded whenever the application issued a notification regarding an event occurrence. These events were classified according to the official nomenclature of the National Oceanic and Atmospheric Administration's (NOAA) Space Weather Prediction Center (SWPC), which categorizes solar flares into three classes (C, M, and X) and radio blackouts on an intensity scale from R1 to R5. An average of 12 monthly occurrences were recorded, including a high-intensity X2.62-class blackout in May, which was registered and reported by various news outlets. The results confirmed the fluctuating nature of solar activity during the analyzed period. While it was not possible to directly correlate the recorded events with specific communication failures documented in amateur radio logs, NOTAMs, or NAVAREA Warnings, the study underscores the relevance of promoting research and employing low-cost tools for the educational monitoring of space weather phenomena. This approach effectively illustrates the connection between solar activity and the vulnerabilities of modern technological infrastructure. By overlaying blackout-affected areas with major air and maritime routes, the systemic nature of this risk is reinforced. For future work, it is recommended to correlate these observational records with communication failures effectively reported by critical sectors, aiming to deepen the understanding of operational impacts.