Empirical model of auroral precipitation power during substorms

Statistical study of electron precipitation features observed by the DMSP F6 and F7 spacecrafts has been performed in order to develop an energetic model of auroral precipitation during substorms. Auroral boundary positions and the average value of electron precipitation flux during all substorm phases were used to calculate the precipitation power (UA). The model enables one to obtain the average precipitation power during all substorm phases of any intensity in the AL index. At the final stage of substorm expansive phase, the global precipitation power increases from about 30 GW for the substorm of |AL|=150 nT intensity to 140 GW for the substorm of |AL|=1000 nT. A simple linear relation UA(GW)=8.4–0.12AL(nT) was deduced by averaging all subphase data points. We compared our results with the energy dissipation determined by other methods and found a good agreement with the calculations of Østgaard et al. [2002. A relation between the energy deposition by electron precipitation and geomagnetic indices during substorms. Journal of Geophysical Research 107(A9), 1246, doi:10.1029/2001JA002003] within the 0.1–100 keV electron energy range.