Greenhouse Effect and Diurnal Cycle
q The very strong downward emission of terrestrial radiation from
the atmosphere is crucial to main the relatively small diurnal
variation of surface temperature.
q If this large downward radiation is not larger than solar heating
of the surface, the surface temperature would warm rapidly
during the day and cool rapidly at the night.
     č a large diurnal variation of surface temperature.
q The greenhouse effect not only keeps Earth’s surface warm but
also limit the amplitude of the diurnal temperature variation at
the surface.