Crossword answers in top half of the grid? Not exactly (8,6)
I believe the answer is:
northern lights
But I can't explain it at all! Could you help me understand?
(Other definitions for northern lights that I've seen before include "Blackpool illuminations?" , "Celestial phenomenon" , "a must-see for Arctic cruisers?" , "What flickers in the sky" , "overhead display" .)