Morphology of the D-region in northern Scandinavia during the campaigns MAC/SINE and MAC/EPSILON in 1987

Abstract

The morphology of the lower ionosphere was examined by the riometer and ionosonde networks in Scandinavia during the campaigns MAC/SINE and MAC/EPSILON. The campaigns were carried out during 1987 when the solar activity was low. The minimum sunspol number 14 was observed in 1986. The sunspot number was already increasing during the year 1987, while the Ap-value and riometer absorption were still decreasing. During the campaign MAC/SINE the rockets were launched during quiet periods, and during the campaign MAC/EPSILON during more disturbed periods. The variations in ionospheric parameters, ionospheric absorption and foF2 are presented for the campaign periods. Some interesting events are pointed out.