Which of the following gases absorbs outgoing terrestrial radiation in the long wave atmospheric window?

Correct option is C

Explanation:
The atmospheric window is a range of infrared wavelengths (around 8 to 14 microns) where little absorption by greenhouse gases occurs, allowing outgoing terrestrial (longwave) radiation to escape into space.
However, some gases can partially absorb even in this window:
· Ozone (O₃) has absorption bands in the infrared region, particularly around 9.6 microns, overlapping with the atmospheric window, thus interfering with terrestrial radiation escape.
Hence, ozone absorbs outgoing longwave radiation in the atmospheric window and contributes to the greenhouse effect.
Information Booster:
· The main greenhouse gases absorbing longwave radiation:
· Water vapour (H₂O)
· Carbon dioxide (CO₂)
· Methane (CH₄)
· Ozone (O₃)
· Ozone plays a dual role:
· Absorbs UV radiation in the stratosphere
· Absorbs infrared radiation in the troposphere
Additional Information:
· (a) Oxygen: Transparent to longwave radiation; not a greenhouse gas.
· (b) Water vapour: Major greenhouse gas, but its absorption bands are outside the central atmospheric window.
· (d) Nitrogen dioxide: Absorbs in visible and UV, not significantly in the IR atmospheric window.