Mj. Ledocq et al., CHORUS SOURCE LOCATIONS FROM VLF POYNTING FLUX MEASUREMENTS WITH THE POLAR SPACECRAFT, Geophysical research letters, 25(21), 1998, pp. 4063-4066
Previous studies have used indirect evidence to argue that whistler-mo
de chorus emissions are generated near the magnetic equator. In this p
aper a spatial survey of wave normals and Poynting vectors computed fr
om three-component electric and magnetic field measurements is used to
show that chorus is generated very close to the magnetic equator. One
surprising result is that there are almost no chorus emissions propag
ating toward the magnetic equator, such as might be expected from high
-latitude magnetospheric reflections. The absence of a reflected compo
nent indicates that the chorus is reabsorbed, probably by Landau dampi
ng, before returning to the magnetic equatorial plane.