How can satellites measure the Earth’s surface temperature when higher layers of the atmosphere are hotter?

Question

How can satellites measure the Earth’s surface temperature when higher layers of the atmosphere are hotter?

In: 2

Answer 1

I’d compare it to watching a distant object through fog:

The fog will block some of the light coming from the object. It will also send some light your way, making it even harder for you to get a clear picture.
But depending on the opacity of the fog and your distance to the object, you can identify it perfectly fine. You automatically sort the information hitting your eye to be either relevant to your question (what’s that object?) or just some noise from the fog.

In a very similar way, the sattelite will see the infrared radiation (IR) from the ground slightly reduced, beause greenhouse gases absorb a part of it. It will also see some IR emitted from the higher layers of the atmosphere.
But both effects are predictable or pretty small (because of low air density especially at high altitudes), so they can be filtered out, leaving you with a signal that reflects actual ground temperature fairly well.