Definition of "ALAN"

Skyglow is a form of artificial light at night (ALAN) whereby the atmosphere scatters light back to Earth, creating a glowing dome of diffused light that can extend hundreds of kilometres into the sea.

2021 March 16, Mattias Green, Yueng-Djern Lenn, 30-Second Oceans: 50 Key Ideas about the Sea's Importance to Life on Earth, 30 Second