Figure 3
From: A case study on occurrence of an unusual structure in the sodium layer over Gadanki, India
Sodium concentration on 18 to 19 March 2007 (NARL, Gadanki). (a) Height-time-concentration map (or lidargram) of the Na atoms during 18 to 19 March 2007 in the altitude 80- to 105-km range of over NARL, Gadanki. (b) Lidargram showing the distribution of Na atoms in the 90- to 105-km altitude showing the ‘λ image ’ structure with concentrations exceeding 2,500 atoms cm−3 saturated to highlight the structure. (c) Sequence of Na concentration profiles. (d) The column density of Na atoms between 93 and 100 km.