Summary of field‐aligned Poynting flux observations from DE 2
Summary of field‐aligned Poynting flux observations from DE 2
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DOI：
10.1029/95gl00570
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发表时间：
1995-07
影响因子：
5.2
通讯作者：
J. B. Gary;R. Heelis;J. Thayer
中科院分区：
文献类型：
--
作者：
J. B. Gary;R. Heelis;J. Thayer
Using DE 2 data of ion drift velocities and magnetic fields, we have calculated the field-aligned Poynting flux (S∥) for 576 orbits over the satellite lifetime. This is the first application over an extended data set of Poynting flux observations from in situ measurements. The data has been sorted by interplanetary magnetic field conditions (northward or southward IMF) and geomagnetic activity (Kp≤3 and Kp>3) and binned by invariant latitude and magnetic local time. Our general results may be summarized as 1) the averaged S∥ is everywhere directed into the ionosphere, indicating that electric fields of magnetospheric origin generally dominate, and 2) the distribution of S∥ for southward IMF can be well explained in terms of an average two cell convection pattern, while for northward IMF a multiple cell convection pattern may be inferred. We have addressed the interesting question of the distribution of upward Poynting flux by binning only upward observations and found that average upward Poynting flux of less than 3 mW/m² may occur anywhere across the high latitude ionosphere. We have also observed a region at high latitudes in the predawn sector where the average upward Poynting flux is of significant size and occurrence frequency during southward IMF and high Kp conditions.
