Atmosphere traps outgoing ir traps remitted light not incoming. Air pressure drops as you go up. Atmpsphere filter and buffer of incoming solar radiation. 90 percent of gas is in lower 15 16 km and most is less dense above that. Longer ev lower energy shorter wv more energy. Sun emits higher energy and is absorbed in higher atmosphere. Different parts of em radioatation penetrate different depths ingra and visible go deep and uv in stratosphere is uv where ozone layer is. Trop is thicker at equator then at poles and defined by temperature gradient and when inversion occurs. Plus 15 at surface and drops in trop bc radiation absorbed surface of planet ir and drops off. The trop and start inverts and increases again is bc ozone layer absorbing uv radiation. Meso not do a whole lot temp drops off a bit. As thermosphere warms up bc gamma and high energy radiation absorbed.