You searched for: “atmospheric extinction
atmospheric extinction (s) (noun), atmospheric extinctions (pl)
The reduction in intensity of light from an astronomical object by absorption and scattering in the Earth's atmosphere: Atmospheric extinction increases when the object is closer to the horizon because of the greater thickness of atmosphere through which its light must travel.
This entry is located in the following units: atmo-, atm- + (page 4) sphero-, spher-, -sphere- (page 3)