Basic Facts About the Aurora

The Energy in the Auroral Light Show

The auroral lights, we see, are indicators that energy is being pumped into the upper atmosphere from space weather disturbances. However, it is only the tip of the iceburg. Only 4% of the energy that is hitting the high latitude atmosphere shows up as the auroral lights. The other 96% heats the neutral atmosphere, causing it to expand, and increases the production of ions in the ionospheric layers.

Compared to the Energy Bombarding the Earth

But if you compare the energy hitting the upper atmosphere to the amount of energy actually contained in the solar wind disturbance raging in the space surrounding the Earth, you begin to understand the true value of the Earth's magnetic shield. Only a few percent of the solar wind energy finds its way into the Earth's atmosphere. This means that only a few tenths of 1% of the energy hitting the Earth's magnetosphere shows up as auroral lights. Small as this sounds, the energy of one auroral storm (~100 million kilowatts) exceeds the total power-generating capacity of the entire United States during the same time interval.




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