Geophysical Research Letters
American Geophysical Union
A hot spot (or spots) can occur in the high‐latitude ionsophere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time‐magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m−1. For electric fields of the order of 100 mV m−1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 °K at 160 km, and decreases with altitude in the F‐region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions.
Schunk, R. W., and J. J. Sojka (1982), Ionospheric hot spot at high latitudes, Geophys. Res. Lett., 9(9), 1045–1048, doi:10.1029/GL009i009p01045.