Fig. 9From: Dependence of mesospheric Na and Fe distributions on electron density at AreciboAll-sky images of the O(1S) 557.7-nm airglow emission obtained using the PSU imager located at Arecibo: a a typical image taken on the night 17–18 March at 02:49 h (AST) showing wave activity with a superimposed pink line that indicates the phase progression; b an image representing data taken at 02:51 h (AST) for the consecutive night 18–19 March 2004Back to article page