In a manner relating to or characteristic of the atmosphere; with respect to atmospheric conditions.
From 'atmospherical' + '-ly' (adverb-forming suffix). Developed to describe actions or conditions evaluated through the lens of atmospheric science.
When meteorologists talk 'atmospherically,' they're using science-speak to mean 'when you look at what's happening in the air and weather,' which is actually pretty specific!
Complete word intelligence in one call. Free tier — 50 lookups/day.