Disturbance storm time index


The disturbance storm time index, also known as the Dst index or Kyoto Dst index, is a measure of the strength of the Earth's ring current.
The ring current around Earth produces a magnetic field that is directly opposite Earth's [magnetic field]; that is, if the difference between solar electrons and protons gets higher, then Earth's magnetic field becomes weaker.
A negative Dst value means that Earth's magnetic field is weakened. This is particularly the case during solar storms.
Its units are typically measured in nT.
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