How Much Does A Cloud Weigh?

MyNameIsFred writes "ABC News is running an article revealing unexpected facts about weather formations. Ever wonder how much a cloud weighs? What about a hurricane? A meteorologist has done some estimates and the results might surprise you..." Reports that include the phrase "more than all the elephants on the planet" are always welcome.

I am not a meteorologist

[drinkypoo]

Or a physicist, or really a member of any pertinent field, but it seems to me that the last bit, about all the elephants ever, is pretty bogus science.

"What we're doing is weighing the water in one cubic meter theoretically pulled from a cloud and then multiplying by the number of meters in a whole hurricane," she explains.

That makes no sense at all. A cloud is very little like a hurricane except that it involves water, air, and differentials of temperature and pressure.

More accurate methods

[StewedSquirrel]

Perhaps a more accurate method would be to extrapolate from the amount of water actually present in a cloud. A "cloud" isn't some well-defined object containing a set density of water. I'm sure a big puffy white one has a LOT less water than a big mean dark one that is the same size.

Then again, when we're talking about clouds... they're just concentrations of moisture that happen to refract and reflect visible light. The air has moisture everywhere. What exactly is the difference in moisture content between a cloud and a "really wet day" in the jungle?

I've seen it rain with very little cloud cover... So while we're at it, why not just weigh the air?

Or we could get around to other even more pointless activities... ANYTHING to get you on /. :-)

Stewey

Re:Target Audience?

[Anonymous Coward]

Most news is written at the 4th grade level... generaly speaking. This would include NBC / CBS / ABC, though I think USA today is written at the 3rd grade level.

It's sad but true.

Cloudless Skies

[chiasmus1]

I've seen it rain with very little cloud cover... So while we're at it, why not just weigh the air?

Here in Japan it gets so humid that sometimes it rains without any clouds in the sky. I have always thought that was interesting.

Re:NEWS ALERT (Summary)

[fiezk]

The cloud is however not heavier than the air surrounding it. The 'surprising' thing about this is how much mass a cubic meter of air really weighs.

Ridiculous

[WebMasterJoe]

We're measuring the weight of clouds? Come on, how about the mass? And the density? ...And I guess the volume, just to round out that formula. The density of a cloud is very very low, less than the air around it (which is why it floats). The article is just a piece of pop science - useful trivia if you're trying to impress drunks at a frat party, but not the sort of thing intelligent people want to start their mornings with.

But it did get me thinking - since the clouds are less dense than air, there is less mass per cubic foot (or meter or whatever), so is the air pressure under a cloud lower? I know low pressure is indicative of a warm/cold front; are the two related?

Re:Ridiculous

[mudrat]

The air pressure below a cloud is not less than the pressure just outside the cloud's 'shadow'. Think of a bath of water. For example, if you float a rubber duck in it then the pressure below the duck will not be less than the surrounding pressure. This is because the pressure at a depth in a fluid is not related to the shape of the container - only to the depth (and other stuff, like temperature).

If you don't belive me then float something large (like a container ship) in a swimming pool, swim up to the edge of the space under it and observe that you don't get sucked in.

So no, the low pressure associated with some weather phenomena is in no way related to the weight of the clouds. In fact, I would guess that clouds would tend to increase pressure by reflecting sunlight back into the space and cooling the atmosphere beneath them.

Re:550 tons

[Idarubicin]

550 tons of electrons;
divided by 9.1E-34 tons per electron;
divided by 6.02E23 electrons per mole;
divided by 96485 moles of electrons per amp.second;
divided by 3600 seconds per hour;
multiplied by 110 volts distribution;

Gives 318 kWh in 550 tons of electrons, delivered to your door in North America, or twice as much energy in Europe.

If you're drawing 400 watts for computer and modem;
and you wasted fifteen minutes on this story;

That's only 3200 readers to use up 550 tons of electrons. Of course, since we're using alternating current, those readers had to return the electrons for reuse by other /.ers. :D