| Auroral Electrojet Index Designed to Provide a Global Measure, Hourly Intervals, of
Auroral Zone Magnetic Activity |
| The Auroral Electrojet (AE) index is designed to provide a global quantitative measure
of auroral zone magnetic activity produced by enhanced ionospheric currents flowing
below and within the auroral oval. Ideally, it is the total range of deviation at
an instant of time from quiet day values of the horizontal magnetic field (H) around
the auroral oval. The hourly AE, AL, AU, and AO indices were derived from hourly scaled
values of magnetic horizontal intensity or the means of indices measured at finer
sample increments (2.5 or 1.0-minute). These indices are derived from a network of
geomagnetic observations that encircle the northern auroral oval. |
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