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Name: Jamin
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Hi, Last week I was flying out of DC, and I counted 7 distinct and broad layers of clouds. How can this be? My understanding is that there are 2 major cloud formation mechanisms (Convective and Stratiform) which can occur separately or at the same time, but I do not understand how these two methods can give rise to 7 layers of clouds in the same altitude profile. Can there really be such a complex pressure profile in the atmosphere over the same height profile? Could you please refer me to other sources so that I can read up on these weather effects?


Your question is similar to one that I answered on the topic "Cloud Layers" for Jean C. You can find that answer in the Ask-A-Scientist database under "Cloud Layers".

However, you have seen an unusual number of cloud layers occurring at one time.

This is an indication of several layers of air where a low enough temperature is reached at the top of the layer to bring the air to the dew point (saturation of the air to produce clouds). This can sometimes be caused by multiple daily inversion layers being built up, one on top of another as the inversion from the previous day is isolated and lifted higher each day. Another possibility is that there was a complex frontal system in the area, such as a cold front plus an occluded front in association with a low pressure area; the stacked layers of air flowing over and under each other in such a complex system can create multiple cloud layers.

David R. Cook
Climate Research Section
Environmental Science Division
Argonne National Laboratory

Water has three phases depending on pressure and temperature.
As a gas: Steam vapor
As a liquid: Water
As a solid: Ice

Clouds are either water or ice particles.

Each phase of water has its own density. Density is the mass per unit volume of a substance. (kg/m3)

Steam vapor has the least density. Water has higher density (usually serves as the standard and is set to 1.0) Ice has an even higher density.

Clouds of water or ice will rise to a level where their density is equal to the density of that particular layer of air at that particular altitude. The seven layers you saw mark seven different density layers in the air column where the clouds are formed.

Ideally, the temperature goes down linearly as altitude increases, but more often than not there are layers of temperature inversion, where the temperature starts getting warmer as altitude increases, at least for a little bit.

So it is quite possible to have several layers of water and ice clouds at several different altitudes in the atmosphere.

Sincere regards,

Mike Stewart

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