The ionospheric response to the CME event of 6-11 January 1997

An active aurora was observed at Eureka, Canada (88.9 degrees N magnetics f ollowing the arrival at the magnetopause of the shock front resulting from the solar Coronal Mass Ejection of 6 January 1997. This onset at 02:20 UT o n 10 January marked the beginning of an aurora which continued until at lea st 15:00 UT on 11 January, as viewed from both Eureka and the CANOPUS site at Ft Smith (67.8 degrees N magnetic). There were enhanced OI 630 nm polar F-region emissions throughout this period, with the IMF B-z controlling the ir form. When B-z was positive, there were continuous polar arcs; when B-z turned negative there were F-layer patches on open field lines. While the s trong H-beta observed over Ft Smith (240 R) in addition to the extended 630 nm emissions and their persistence over two days suggested a red aurora of global proportions, it apparently did not extend to latitudes below 60 deg rees. There was a moderate magnetic storm associated with the aurora, but t he D-st index reached only - 81 nT on 10 January. (C) 1999 Elsevier Science Ltd. All rights reserved.