Fig. 12
From: Post-sunset rise of equatorial F layer—or upwelling growth?
A composite plot of h’f curves (at integer plasma frequencies) for KTB (bold lines) and CPN (thin lines) for 27 March 2006. First upward arrow marks the time when upwelling was seen over CPN. Second arrow (20 min later) marks the time when EPB was observed with EAR and when a mild upwelling was observed over KTB