St. Elmo's fire

St. Elmo's fire was, according to the Fourth Doctor, a phenomenon that caused "a sort of halo effect around the masts of ships" at sea. He suggested that a phenomenon of that kind explained why Leela saw him ringed in light after the Swarm attacked his TARDIS. (TV: The Invisible Enemy)

The appearance of the London Eye when activated by the Nestene Consciousness (TV: Rose, PROSE: Operation Mannequin) during the Dummy Massacre in March 2005 was compared on the Who is Doctor Who? website to fireworks and St. Elmo's fire. (PROSE: Dummy Massacre)

Behind the scenes
St. Elmo's fire is misspelled as "St. Elmose fire" in Dummy Massacre.