SUMMARY OF FIELD-ALIGNED POYNTING FLUX OBSERVATIONS FROM DE-2

Using DE 2 data of ion drift velocities and magnetic fields, we have c alculated the field-aligned Poynting flux (S-parallel to) for 576 orbi ts over the satellite lifetime. This is the first application over an extended data set of Poynting flux observations from in situ measureme nts. The data has been sorted by interplanetary magnetic field conditi ons (northward or southward IMF) and geomagnetic activity (Kp less tha n or equal to 3 and Kp >3) and binned by invariant latitude and magnet ic local time. Our general results may be summarized as 1) the average d S-parallel to is everywhere directed into the ionosphere, indicating that electric fields of magnetospheric origin generally dominate, and 2) the distribution of S-parallel to for southward IMF can be well ex plained in terms of an average two cell convection pattern, while for northward IMF a multiple cell convection pattern may be inferred. We h ave addressed the interesting question of the distribution of upward P oynting flux by binning only upward observations and found that averag e upward Poynting flux of less than 3 mW/m(2) may occur anywhere acros s the high latitude ionosphere. We have also observed a region at high latitudes in the predawn sector where the average upward Poynting flu x is of significant size and occurrence frequency during southward IMF and high Kp conditions.