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Mid Level Clouds

Clouds

Beginning of Module


Created by UW-Madison, 2002
 Mid-level clouds offer scientist information about the middle part of the troposphere. Recall that the troposphere is the lowest part of the Earth’s atmosphere where conditions support living organisms, although the stratosphere, mesosphere, and thermosphere also play their part supporting life on earth.
We use the prefix "alto" to indicate mid level clouds.
Altostratus clouds develop when the middle layers of the atmosphere are moist and are lifted slowly, they rarely block out the sun and are fairly uneventful, although may be the precursors of a rain event.

Altocumulus clouds tell a completely different story. The presence of altocumulus clouds in the sky means that convection is occurring quite high up. In the summer, altocumulus clouds that rises up in little castle-like turrets (castellanus) may be a precursor to severe weather.


Altocumulus clouds from below
Visible satellite image
IR satellite image
The first satellite image is a visible image using reflected light, the second satellite image is an IR image that measures thermal energy.

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