Photometric studies of the great red aurora March 13 and 14, 1989.

Extended photometric coverage of the great red aurora of March 13 - 14, 1989 was obtained at the Rabbit Lake Observatory located in northern Saskatchewan, at an eccentric dipole latitude of 65.3°. The aurora was active much of the time and its brightenings were accompanied by poleward expansions to as far north as the observatory. Combining these observations with those at low latitudes suggest a large auroral expanse from an equatorward edge of about 30° to a poleward edge of about 65° magnetic latitude. One key value of the optical data was the semicontinuous monitoring of major auroral emission intensities. The measurements along with related worldwide observations will assist in gaining a better understanding of the magnetospheric conditions producing such major widespread auroras.