Afternoon auroral spots - last update: 1 July 1996, 1530 UT (RR)

The post-noon reagion (around 14 MLT) seems to have a special significance in magnetospheric physics. The other R1 field-aligned current maxima occurs there (see also Bythrow et al, 1994), and measurements have shown strong particle precipitation occurring there (McDiarmid et al., 1975; Evans, 1985). These relate to a general enhancement of auroral intensity within this region (Snyder and Akasofu, 1976; Shepherd et al., 1976; Cogger et al., 1977; Murphree et al., 1981; Meng and Lundin, 1986). It is possible that this activity is somehow also linked with the nightside substorm activity (Lui et al., 1987).

The auroral activity consists often of separate bright spots with uniform spacing, estimated to be about 1.5 hours of local time by Lui et al. (1987). Similar spots have also been seen in the nightside, and they may correspond to deformed auroral arcs (folds etc.) when seen from the ground.


See also: