| Auroral Electrojet Index Designed to Provide a Global Measure, l-minute Intervals,
of Auroral Zone Magnetic Activity |
| The Auroral Electrojet index (AE) 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. These indices are computed from a network of geomagnetic observations,
some recording digitally and others as analog, which encircle the northern auroral
zone. The AE computation uses horizontal magnetic field measured at 1-minute intervals.
AE plus the supplemental indices AL, AU, and AO are contained in this data file. For
earlier years, the AE indices were derived at 2.5 minutes. Also, hourly mean indices
are calculated. |
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