Black aurora

spaceweb@oulu.fi - last update: 18 February 1997, 1100 UT (RR)

Black aurora is a lack of auroral emission in a small, well-defined region within an otherwise uniform, diffuse background or within auroras exhibiting a degree of shear behaviour intermediate between that of diffuse and discrete aurora (e.g., Davis, 1978). It appears to be a common feature of the midnight sector during late substorm recovery phase (Trondsen and Cogger, 1997).

References

Davis, T. N., Observed microstructure of auroral forms, J. Geomagn. Geoelectr., 30, 371-380, 1978.
Trondsen T. S. and L. L. Cogger, High-resolution television observations of black aurora, J. Geophys. Res., 102, 363-378, 1997.