Tr. Robinson et al., FIRST EISCAT OBSERVATIONS OF THE MODIFICATION OF F-REGION ELECTRON TEMPERATURES DURING RP HEATING AT HARMONICS OF THE ELECTRON GYRO FREQUENCY, Journal of atmospheric and terrestrial physics, 58(1-4), 1996, pp. 385-395
Results are presented from recent ionospheric F-region modification ex
periments in which the heater induced anomalous absorption and electro
n temperature changes were measured for a variety of heater frequencie
s which included the third and fourth harmonics of the electron gyro f
requencies. The results indicate that there are strong minima in the r
esponses of both anomalous absorption and electron heating in the vici
nity of the two harmonic frequencies. These new observations provide e
vidence for the view that anomalous electron heating in the presence o
f small scale field aligned plasma irregularities dominates over colli
sional heating at high latitudes.