Data of the Intercosmos 24 (IC 24) satellite and the ground-based complex o
ptical and ionospheric measurements in the region of the stable auroral red
(SAR)-arc are presented. Photometric observations were carried out at the
Maimaga station (invariant latitude Lambda =56.5 degrees, geomagnetic longi
tude lambda(m)=200 degrees) and vertical incidence ionospheric soundings we
re made at Yakutsk (Lambda =55.6 degrees, lambda(m)=200 degrees) and Zhigan
sk (Lambda=60.4 degrees: lambda(m)=195 degrees) stations. It is shown that
when SAR-arc arises for the interval similar to 15 min, the local minimum o
f the F-region electron density is formed, and in the ionograms typical sig
natures of the polarization jet or SAID are observed. Simultaneously, the h
eight of the regular F2 layer increases. This evidences that strong electri
c field (E similar to 100 mV/m) exists at the F2 layer heights. In this cas
e, in addition to the SAR-arc energy sources, the effect of the ion-frictio
nal heating is turned out to be important. Simultaneous measurements aboard
the IC-24 satellite at the altitudes similar to 500 km above the SAR-arc a
lso show 3 divided by 5 times decreased electron density. The electron temp
erature elevates up to similar to 4500 K. At altitudes of 2400 km the ion d
ensity increases by 30 - 40 % and T-e rises up to 6300 K. (C) 1999 Elsevier
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