Chris from Virginia: How can CALIPSO "see" the thin, almost invisible clouds, and why is it important?
The very thin clouds are an indicator of vertical motion in the atmosphere.
And so our LIDAR technique is very sensitive because we use short pulses of light instead of using reflected sunlight,
so we can cancel out the effects of the sunlight reflecting from the Earth's surface,
and this makes it possible for us to see very thin cloud layers.
And the reason these thin clouds are important is because they can,
they can alter the temperature of the atmosphere at the altitudes and so affect the circulation of the air.