Talk of Pavle ARSENOVIC

(BOKU) "Solar Storms and Earth’s Shield: What Happens When the Magnetic Field Weakens?" Located about 15 to 35 km above the surface, it acts as a natural shield that prevents dangerous levels of UV radiation from reaching the ground. The ozone layer can be depleted by Solar Particle Events (SPEs), which are short-lived bursts of high-energy particles which can enter the Earth’s atmosphere and disrupt its chemistry. Currently, the Earth’s geomagnetic field deflects most of these particles, limiting their impact to the polar regions. However, geological records demonstrate periods throughout Earth’s history where the geomagnetic field was significantly weaker. During those periods, ionizing particles can enter Earth’s atmosphere at lower latitudes and damage the ozone layer, resulting in increases in surface UV radiation. We provide the first detailed simulations of the impacts of extreme SPEs, and we show that under current geomagnetic field conditions there would be major impacts on atmospheric ozone levels and surface UV radiation levels, posing risks to human health. However, we also demonstrate that in previous periods when the geomagnetic field weakened, the effects of solar storms would pose major risks to human health, and the stability of multiple climatic- and ecosystems. This study confirms the vulnerability of our environment to space weather, emphasizing the need to prepare for future events.