The general vibe that one picks up depending on the population and activity of felines in the area.
"I'm lovin' the catmosphere around here."
"Hey, dude. You pickin' up on all this catmosphere?"
The smell of cat in a residence. Varies from barely detectable (1 cat) to retch inducing (10 plus). In extreme cases the catmosphere can penetrate clothing leaving the lingering odour of sadness.
Have you ever seen Catwoman? No, but I've smelled her catmosphere, and I had the flu at the time!