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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.
Clouds are made of a lot of water. A lot of water is heavy. Clouds are heavy.
In other news, the sky is blue and grass is green.
It isn't saying much when you have to relate the measurement of weight to an elephant so the populous that reads it can grasp the magnitude of the number. In fact I find that rather pathetic...
++mse61--
I always knew that elephants could fly...
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Assume an elephant weighs about six tons, she says, that would mean that water inside a typical cumulous cloud would weigh about one hundred elephants.
Somehow it reminds me of RIAA's math equivalent.
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Error 500: Internal sig error
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.
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.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Doesn't anybody know that elephants are non-standard units? Give me something I can work with here, people. How many library of congresses would it take to equal the weight of a storm cloud?
Stephen
Fault loves the past, worry loves the future, but content enjoys the present.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
... the cloud is a witch! No wait, ducks not elephants. n/m
Who on earth is this written for? It says at the bottom that at least two people contributed to the report. The language is like that of a 4th grader. Is this what all ABC News reports look and/or sound like?
This makes the BBC seem like something written by Stephen Hawking.
A solution to the problem with music today
We are talking water. Water is very heavy. It is just that water in a cloud is in vapor form, and also floating in the sky that we sort of forget that it is still water.
And to be honest, the numbers (200,000 elephants in a storm cloud) don't shock me. Think of the destruction caused by floods, which are caused by rain. In some ways, it makes sense.
It is human nature to take shortcuts in thinking.
Cecil Adams answered this a few years back. Sure he uses 747's instead of elephants, but his answer is a bit more detailed.
I wonder if she has ever considered just how hot is the sun. Wow, its hotter than all the space heaters that have ever been made turned on in the drying closet and you locked in for the whole weekend with only a bottle of soda and some salt crackers. Although by saturday night it would feel pretty much the same.
They use elephant weights in the article to make it easier to visualize. A Hurricane is 40 million elephants. That's just so much easier to visualize than 240 million tons (cubic meters) of water.
Jason
ProfQuotes
I'd guess it weighs about as much as Vaporware.
paintball
I see no reason why most people should have some natural appreciation of what "550 tons" actually means.
Boffoonery - downloadable Comedy Benefit for Bletchley Park
Yes, and I have a car that weighs over 1 trillion fleas.
Did I mention my laptop that must weigh over 50 field mice...
Still #1 -- Lonely Gay Geek
The real question is how many midgets does an elephant weigh? If have 48 midgets per elephant, and I have 600 elephants per cloud, then....
This is my sig.
Are they Metric or Imperial elephants?
hurricanes are so destructive what with 200,000 elephants flying all over the place.
From the article "That means the water in one hurricane weighs more than all the elephants on the planet. Perhaps even more than all the elephants that have ever lived on the planet."
Assume an elephant generation is 50 years. Assume the average number of elephants in Africa at any one time is 100,000 (this will be way low historically). So, 40 million elephants are born in 400 generations, or only 20,000 years.
So there's no way this atatement "more than all the elephants that have ever lived on the planet" is correct.
When I was studying physics the lecturer was very insistent about us being able to do back of the envelope calculations - for example, how many photons does a 1.5 volt torch make on a full battery.
Cheers,
James
This opens up a whole new world of "your mom" jokes... "Your mom weighs as much as a cloud." How many people are gonna be able to figure that one out? :-D
Sure, it can do easy conversions like 1 pint in decilitres.
But can it do 1 cloud in elephants? No!
Perhaps Google isn't god after all.
Boffoonery - downloadable Comedy Benefit for Bletchley Park
Clouds are composed primarily of small water droplets and, if it's cold enough, ice crystals. The vast majority of clouds you see contain droplets and/or crystals that are too small to have any appreciable fall velocity. So the particles continue to float with the surrounding air. For an analogy closer to the ground, think of tiny dust particles that, when viewed against a shaft of sunlight, appear to float in the air. Indeed, the distance from the center of a typical water droplet to its edge--its radius--ranges from a few microns (thousandths of a millimeter) to a few tens of microns (ice crystals are often a bit larger). And the speed with which any object falls is related to its mass and surface area--which is why a feather falls more slowly than a pebble of the same weight. For particles that are roughly spherical, mass is proportional to the radius cubed (r3); the downward-facing surface area of such a particle is proportional to the radius squared (r2). Thus, as a tiny water droplet grows, its mass becomes more important than its shape and the droplet falls faster. Even a large droplet having a radius of 100 microns has a fall velocity of only about 27 centimeters per second (cm/s). And because ice crystals have more irregular shapes, their fall velocities are relatively smaller. Upward vertical motions, or updrafts, in the atmosphere also contribute to the floating appearance of clouds by offsetting the small fall velocities of their constituent particles. Clouds generally form, survive and grow in air that is moving upward. Rising air expands as the pressure on it decreases, and that expansion into thinner, high-altitude air causes cooling. Enough cooling eventually makes water vapor condense, which contributes to the survival and growth of the clouds. Stratiform clouds (those producing steady rain) typically form in an environment with widespread but weak upward motion (say, a few cm/s); convective clouds (those causing showers and thunderstorms) are associated with updrafts that exceed a few meters per second. In both cases, though, the atmospheric ascent is sufficient to negate the small fall velocities of cloud particles. Another way to illustrate the relative lightness of clouds is to compare the total mass of a cloud to the mass of the air in which it resides. Consider a hypothetical but typical small cloud at an altitude of 10,000 feet, comprising one cubic kilometer and having a liquid water content of 1.0 gram per cubic meter. The total mass of the cloud particles is about 1 million kilograms, which is roughly equivalent to the weight of 500 automobiles. But the total mass of the air in that same cubic kilometer is about 1 billion kilograms--1,000 times heavier than the liquid! So, even though typical clouds do contain a lot of water, this water is spread out for miles in the form of tiny water droplets or crystals, which are so small that the effect of gravity on them is negligible. Thus, from our vantage on the ground, clouds seem to float in the sky.
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
There are 10 kinds of people in the world. Those who understand binary and those who don't.
I, for one, welcome our new meteorologist overlords!
Here in Japan it gets so humid that sometimes it rains without any clouds in the sky. I have always thought that was interesting.
A 500 square meter area got an average rainfall of 3cm
500 * 100 = 50000 square cm
3cm * 50000 cm^2= 150000 cm^3
Pure Water having a specific gravity of 1.00
150,000 cm^3 * 1.00 = 150,000grams or 150Kg
Using the imperial system we have to resort to using inches, hands, feet, arms, britney spears, elephents, and the odd library of congress.
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It took quite a lot of research, but I did find out how much a flea weighs. It is approximately one millionth of a pound, or .000001 pounds. So, 1 trillion times 1 millionth of a pound would be... 1,000,000 pounds! It's closer to weighing as much as one billion fleas.
Paul Anderson
"I drank WHAT?!" -- Socrates
550 tons is the weight of all the electrons that have been inconvenienced, although momentarily, by people who read this stupid article online, and then couldn't keep from posting on /. about how asinine it was. (Oops).
For that many electrons, we could have downloaded ourselves a few Libraries of Congress. Too late now, they're all wasted. We'll have to get the 20,000 CD-ROM worth of data delivered to our door by an elephant.
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Is that what professionial journalism has come to?Why must people keep abusing the phrase, "begs the question?" It does not mean "causes us to question" or "makes me wonder." Just because MANY people keep making the same mistake does not make it so.
</grammar nazo>
That post was not insightful. It was just the combination of certain letters and punctuation that made it appear insightful.
Try skydiving trough a cloud. The do indeed look fluffy and soft from an airplane, but when you fall trough them at 200-280kmh, it feels quite different.. All those small droplets hitting your bare skin feels like hundreds or thousands of small nails, and larger drops can be be painful trough thin clothing as well..
Not to mention hail within clouds. Hail is really, really painful. Skydivers really don't like hail. At all.
How much does all the spam sent on the internet each day weigh?
/dev/null
Is there any place big enough to store it?
Yes:
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Has anyone converted these figures into units we Brits can understand. Normally area here is expressed as multiples of the area of Wales (Jack Straw, the foreign secretary, uses this a lot). For smaller areas we use the Football (Soccer) pitch. Volume is a bit trickier as there is not a fixed unit but the volume of something is described by how many of the relevant objects would be needed to fill the Albert Hall. As for weight we need it as multiples of the England Pack (That's the eight guys in the scrum for you non-rugby players). So come on british mathematicians, your country needs you. How many England Packs does a typical raincloud over Lords Cricket Ground weigh, how many of them would be need to fill the Albert Hall and what fraction of the area of Wales would it cover ?
No but, yeah but, no but...
You get the giant stepladder and I'll get the big bucket and scales...
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If they did, they would fall out of the sky. They have a mass, but no weight. Weight is the measure of the downward force a mass exerts. That is why you don't weigh as much on the moon. You have the same mass, but less weight. Clouds float, so they are weightless. If clouds had weight, you would need skyhooks to keep them up in the air.
This is courtesy the Scientific American website. There is more information out there.
Seems like nobody mentioned this before. Here seems to be a better source for the answer.
My cats ate my karma. They also wrote this comment.
Ehh... Actually, 6 tons is exactly 6000 kilograms.
Ehh...what do you expect from a physicist? Actually I'd have expected that he'd said something like "6 tons are well in the range of 10^4 kilograms"....
According to the recents changes at the DMCA, you are not allowed to reverse engineere a cloud to know it's composition. Doing so can force you to pay up to 250,000$ per violation, and 6 month in prison. Think twice when you do such things
Clouds float because the water droplets in them are tiny, and have a large surface-to-volume ratio. If the force caused by the friction of rising air currents on the droplet's surface is larger than the weight of the droplet, the droplet rises with the air. When the droplets increase too much in size, it rains.
And what if the air in the cloud isn't rising? Then the water droplets fall, very slowly. If they are too small to cause rain, when they reach lower layers of the atmosphere they evaporate, because air lower down is, normally, warmer.
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?
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MASS != WEIGHT
"Times may change, but standards must remain the same." - George Carlin.
a square meter is 100x100 square cm or 10000. So you have 500 * 10000 * 3 / 1000 = 15000kg
So a square km getting 3cm of rain would be 2000 times that (1000^2/500) which is 30 million kg.
In Soviet Russia, hot grits put YOU down THEIR pants.
Skydivers really don't like hail. At all.
:)
They are lucky then that they haven't hit any of the elephants yet
--Grandpa Simpson
The Simpsons Episode 2F31 "A Star is Burns"
In fact:
The 100,000 elephants is low even for today. And as recently as 1970 there were an estimated 1.5 million wild elephants in Africa alone.
Fifty years isn't a bad guess for generations. this article puts life-span at 60 years... but, ater factoring in early mortality, historical average life was probably much, much lower.
Continuing back-of-the-envelope calculations:
Let's say that an average historical elephant population was two million...
... and average life-span was twenty years...
... and assuming an historical period of, say, ten thousand years...
Silly article.
If you add up molecular weights and use the gas laws (PV=nRT), youll find that water vapor -- which is what clouds are made of, until they rain out -- is lighter than air.
The gas laws tell you basically that when P and T and R are constants, as they are in any small region of the atmosphere, the volume is proportional to the number of moles of gas that you have. I don't know how many cubic meters of gas make up a mole, up in the clouds, but I know it's a constant, and... a mole of N2 (nitrogen gas, which makes up 60% of the air) weighs 28 grams, and a mole of O2 (oxygen) weighs 32 grams, and a mole of CO2 (carbon dioxide) weighs 44 grams. But a mole of H20 weighs in at only 18 grams. So, water is lighter than air.
This is why barometric pressure decreases when clouds are overhead.
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