Global model of low frequency chorus (fLHR < f < 0:1fce) from multiple satellite observations

Whistler mode chorus is an important magnetospheric emission, playing a dual role in the acceleration and loss of relativistic electrons in the Earth's outer radiation belt. Chorus is typically generated in the equatorial region in the frequencyrange 0.1 - 0.8fce, where fce is the local electron gyrofrequency. However, as the waves propagate to higher latitudes, significant wave power can occur at frequencies below 0.1fce. Since this wave power is largely omitted in current radiation belt models we construct a global model of low frequency chorus, fLHR < f < 0.1fce, using data from six satellites. We find that low frequency chorus is strongest, with an average intensity of 200 pT2, in the pre-noon sector during active conditions at mid latitudes (20o < |λm| < 50o) from 4 < L∗ < 8. Such mid-latitude, low frequency chorus wave power will contribute to the acceleration and loss of relativistic electrons and should be taken into account in radiation belt models.

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