|Cornwall, UK Green Flash imaged by Ryszard Gorell in April 2009. ©Ryszard Gorell, shown with permission.
Almost a classical inferior mirage flash where the last sliver of sun at the horizon turns an intense green for just a second or so. This type of flash, produced by warm air beneath cooler, is photographed rather less often than the mock-mirage flash where green flashes come and go on the upper limb when it is further above the horizon. However, the inferior mirage flash is more easily seen visually.
Almost classical? Green appears each side of the main solar image earlier on. There 'might' be a narrow inversion layer very close to the horizon producing a ducted mirage.
Ryszard used a Canon 350D with cable release and drive mode set to 'burst'. Some images have been omitted. The images show that a clear sky is not necessary for a green flash.