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Desert Diary
Climate/Cloud Weight


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Ah, to be a cloud, floating weightlessly, wafted here and there by gentle breezes. Well, considering spring winds, maybe not gentle breezes, but surely clouds don't have a weight problem. Or do they? After all, clouds are made of water droplets, and water's heavy.

Although clouds come in all sizes, we can make a few assumptions to see just how nebulous they really are. Let's take a pretty good sized one, and mentally harass it into a sphere with a radius of a kilometer, since it's a lot easier to figure out the volume of a sphere than trying to take into account all the bulges of a real cloud. There's one more problem though. Clouds vary a lot in their density, so a cubic meter of cloud can hold between about 1/10 of a gram to over 5 grams. OK, let's pick a figure of 1 gram. The 4 billion cubic meters of our tame cloud, then, weighs 4 billion grams, or 4 million kilograms—or in English, about 8,800,000 pounds! Fluffy? I think not!
pen and ink


Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.

Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.


Chihuahuan Desert monsoon clouds. Fluffy? Photograph by A. H. Harris.



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