Evaluation of SuperMAG auroral electrojet indices as indicators of substorms and auroral power

[1] We use magnetometer chains collaborating with SuperMAG to derive SME, a generalization of the auroral electrojet indices calculated from 100 or more sites instead of the 12 used in the official auroral electrojet indices, AE(12) = AU(12) − AL(12). We investigate how these various indices relate to nightside auroral power by using both particle (DMSP) and image (Polar Ultraviolet Imager (UVI)) data. The best correlation is between SME and total nightside auroral power, namely, r = 0.86. Hence, nearly 3/4 of the minute-by-minute variance in nightside power can be determined by SME alone. Interestingly, although the geophysical meaning of AE(12) has sometimes been challenged, we show that even that index…

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  National Aeronautics and Space Administration

  Award: NNX08AM32G