A new study has revealed a surprising connection between lightning strikes on Earth and electron showers in the planet's inner radiation belt. Researchers discovered that electromagnetic waves generated by lightning can trigger these showers, challenging previous understanding of the inner radiation belt's dynamics.
The discovery emerged from an analysis of decades of data collected by the SAMPEX satellite, which detected bursts of high-energy electrons entering Earth's atmosphere. While scientists expected these events to originate from the outer radiation belt, where chorus waves are known to knock electrons out of place, the study found that some events originated from the inner radiation belt.
This finding is significant because chorus waves are not prevalent in the inner radiation belt. Further investigation revealed that lightning-generated whistlers, electromagnetic waves produced by lightning strikes, can interact with electrons in the inner radiation belt, triggering the observed electron showers.
However, the study also found that lightning alone was not sufficient to cause these events. Only lightning that occurred after geomagnetic storms, disturbances in Earth's magnetic field caused by solar activity, resulted in the electron bursts. This suggests a complex interplay between Earth's weather and space weather in shaping the inner radiation belt.
The discovery sheds new light on the dynamic nature of Earth's radiation belts and the interconnectedness of Earth and space. It also highlights the importance of considering unexpected observations and re-evaluating existing theories in scientific research.