Speaker
Description
Solar activity events release vast amounts of energy,
including radio waves, X-rays, ultraviolet radiation, and energetic
particles, which interact with the Earth's ionosphere and can disrupt radio
wave propagation, affecting radio communications. They can either
enhance reflections, enhancing long-distance terrestrial communications,
or cause signal degradation and absorption, respectively depending on
whether the increased ionization affects the upper or lower layers of
the ionosphere. In the first case, the solar cycle modulates the Maximum
Usable Frequency (MUF), the highest frequency usable for radio
communication between two Earth-based points. The Auger Engineering
Radio Array (AERA) of the Pierre Auger Observatory was developed to
measure the radio emission from extensive air showers in the 30-80 MHz
band. We examine the impact of solar activity on AERA data collected
over approximately 11 years. We report the detection of different types
of solar radio bursts and we investigate how increased solar radiation -
particularly in the X-ray and extreme ultraviolet bands - also affects
measurements in the AERA energy band. Our results show a remarkable
correlation between the MUF and the broadband noise observed in the
30-40 MHz frequency range. Radio blackouts are also observed in AERA
spectrograms in coincidence with those reported by the National Oceanic
and Atmospheric Administration (NOAA). These findings highlight the
complex interplay between solar activity and radio wave propagation,
which is also relevant for cosmic-ray detection.
| Collaboration(s) | Pierre Auger Collaboration |
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