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

An active aurora was observed at Eureka, Canada (88.9 degrees N magnetic) following 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 on 10 January marked the beginning of an aurora which continued until at least 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 sub(z) controlling their form. When B sub(z) was positive, there were continuous polar arcs; when B sub(z) turned negative there were F-layer patches on open field lines. While the strong H 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 degrees . There was a moderate magnetic storm associated with the aurora, but the D sub(s) sub(t) index reached only -81 nT on 10 January.