Stories tagged atmosphere

It turns out that our best predictor for earthquakes may be high in the sky rather than deep underground. Before the recent quake in Japan, the atmosphere above its epicenter heated dramatically as a result of radon released from Earth's crust during smaller movements. This radioactive gas triggered condensation of water in the air, which released a large amount of heat.

Mar
29
2011

By the way, when you read about the gigatons of carbon emissions that human activities emit each year, it's helpful to have some perspective:

Let's talk gigatons--one billion tons. Every year, human activity emits about 35 gigatons of [carbon dioxide] (the most important greenhouse gas). Of that, 85% comes from fossil fuel burning. To a lot of people, that doesn't mean much -- who goes to the store and buys a gigaton of carrots? For a sense of perspective, a gigaton is about twice the mass of all people on earth, so 35 gigatons is about 70 times the weight of humanity. Every year, humans put that in the atmosphere, and 85% of that is power. Large actions, across whole nations and whole economies, are required to move the needle.

By comparison, our atmosphere is small--99.99997% of our its mass sits below the Karman line, which is often used to define the border between Earth’s atmosphere and outer space. At 62 miles above Earth's surface, it’s about as high as the distance between St. Paul, MN, and Menomonie, WI.

The oceans also absorb some of that carbon dioxide, but not without consequence.

Of course, the great part about being responsible is having capability--if our inventions bring about such transformations in the air and oceans, then couldn't we be inventive enough to reduce their negative impacts?

It's Friday, so it's time for another Science Friday video. Science Friday
Science Friday
Courtesy Science Friday
"Engineer James Bird estimates that he watched thousands of bubbles pop while he was getting his Ph.D. at Harvard University. With the help of high-speed cameras, Bird and his colleagues discovered that when interfacial bubbles--bubbles resting on water or a solid--pop, they give birth to a ring of baby bubbles. The discovery, published in Nature, has implications for soda drinkers and global climate estimates."
May
26
2010

I enjoy working with our team to develop on-line interactive education activities. We are in the final testing of whose goal is to teach about the balance of global water, land coverage, atmosphere and cloudiness required to create a "liveable planet". If you want to play with it and give us feedback - here is the link:

http://profhorn.meteor.wisc.edu/wxwise/climate/makeplanet.html
The goal is to make a habitable planet by adding enough water, atmosphere and clouds to reach a global average temperature of about 15°C (59°F). You can mix and match, add or remove.

* Drag (and drop) an item from the right side to the left to add that element
* Drag (and drop) from the left are back to the right to remove that element
* HINT You must put at least 3 clouds by the planet!!

There is a timer to see how fast you can make the planet livable.

Dec
10
2009

Wondrous lights in the sky!: But, no, this isn't it. This is the Hard Rock Cafe, one of the other signs of the apocalypse.
Wondrous lights in the sky!: But, no, this isn't it. This is the Hard Rock Cafe, one of the other signs of the apocalypse.Courtesy otubo
Early this week, the good people of Norway looked up from their frantic vitamin D foraging into the dark, pre-dawn sky above the city of Tromsø to see a bizarre spectacle. A massive, glowing spiral hung in the sky, its eerie light reflecting from the frosty hair and pale, cod oil-smeared faces of the people below. Some of the understandably bewildered Tromsønians cowered before the surreal apparition, crouching behind boulders and rusted car hulks, while others boldly hissed and flailed at it, scratching ineffectually at the frigid air with fingernails worn to milky stubs from pawing at packed snow to reveal the tender lichen beneath. All were afraid, for they knew that what they beheld was surely the beginnings of an inter-dimensional portal, or the atmospheric wake of an alien spacecraft (if not somehow both.)

I should perhaps mention, at this point, that my understanding of Norway and Norwegians is fairly limited. I do know that Tromsø is 300 km north of the Arctic Circle, so when I said “pre-dawn” I was being a little poetic—Tromsø won’t see sunrise until mid-January. So, to arrive at my conception of a citizen of Tromsø in December, I took what I’m like, in St. Paul, MN, on a pretty chilly December 10th, and moved that image up to the 69th parallel. I imagined something like Gollum, but wearing a fur parka. This doesn’t quite mesh with reality, but I’m pleased with it.

At any rate, these hearty, enlightened Scandinavians (or slippery tundra goblins, whichever you prefer) saw this in the sky recently. Click on that. It’s interesting.

What was it? Alien attack? The Eye of Sauron? (JK. The Eye of Sauron was fiery. Y’all know that.) A woooormhole? Is the aurora borealis fed up with being harmless?

No. It turns out that the remarkable effect was caused by something much more mundane: a malfunctioning rocket. Specifically, it was a Russian missile test failure. A submarine in the White Sea test-fired a Buluva nuclear-capable missile, and the darn thing malfunctioned, said the Russian Ministry of Defense. In its death throes, the missile made some neat-o clouds in the upper atmosphere, and they apparently caught the light in a pretty way.

Here’s a video explaining how such things work. (This was released before the official Russian explanation, I think.)

So there you go. Nothing to worry about. Just an ol’ malfunctionin’ Ruskie nukular missile.

Er… what?

Jun
07
2009

The King of All Clouds: ... here to rule the skies
The King of All Clouds: ... here to rule the skiesCourtesy akakumo
Did you know that mathematical equations can calculate the temperature, wind speed, and humidity of clouds? Well, the Center for Multiscale Modeling of Atmospheric Processes (CMMAP, pronounced “see-map”) is using these equations and developing a revolutionary approach to climate modeling that will help us understand the roles of clouds today and in the future.

So what is climate modeling exactly? Good question. Think of a giant grid that covers the globe, with cells the size of Delaware. Within each grid, the mathematical equations that I mentioned above are used to predict weather forecasts and climate simulations. But there’s a problem with this grid system: the clouds are much smaller than the cells used in the global models, thus creating a large source of uncertainty in today’s climate models.

CMMAP has come up with a solution to this problem called multi-scale modeling framework (MMF). Their radical new approach will simulate realistic cloud processes in a tiny-fraction of each Delaware-sized cell, greatly improving the climate model. In order to represent each small-scale process, scientists have invented equations that define the temperature and moisture content in a cloud based on the atmospheric conditions in the entire grid cell. Though this is quite an advancement from the technologies of the past, there is still work to be done to accurately represent clouds in the climate model. As developments in MMF continue, CMMAP could potentially hold the key that is necessary in unlocking the mystery to understanding the weather and climate.

If you’d like to learn more about the formation of clouds or more research that CMMAP is conducting, check out the links!

Oct
03
2008

What on earth am I supposed to do with this thing?: A pterosaur considers his situation.
What on earth am I supposed to do with this thing?: A pterosaur considers his situation.Courtesy John Conway
Paleontology, y’all, paleontology. We’ve got these bones, these fossilized bones. And they’re nice bones, don’t get me wrong, but sometimes they leave a little to be desired when it comes to reconstructing the nitty gritty and sticky details of what living dinosaurs (and pterosaurs, ichthyosaurs, mosasaurs, therapsids, etc) were actually like. A skeleton can give us a good idea of a creature’s general shape; it can show where the muscles went (more or less), what sort of food it ate, how it probably moved—that kind of thing. But how did they behave? What color were they? Exactly how strong were they? There are a whole slew of questions that get to be a little tricky.

So, how do paleontologists go about answering these questions? They get creative, they study all the tiniest details of the fossils, and, sometimes, they look to living animals for analogy—that is to say, if an animal alive today that lives in a similar environment to that of an extinct animal, and has a similar body type to the extinct animal, you might be able to base knowledge of the extinct animal on what you know of the living animal.

It’s a valuable avenue of study, but dinosaurs and their ilk were pretty different, after all, so how far do you think can we take analogies to living creatures?

And now on to the news item.

A Japanese researcher has opened up his sass-box and gotten all up in the faces of paleontologists around the world. Pterosaur specialist paleontologists are particularly fired up, and they’re a dangerous bunch. “Peer review” among pterosaur specialists, as I understand it, involves switchblades, and the majority of the community sports eye-patches.

This scientist, Katsufumi Sato of the University of Tokyo, is saying that pterosaurs (all of the huge extinct flying reptiles) probably maybe couldn’t actually, you know… fly.

Oh no you di’en’t!

Says Sato: Yes, yes I did. Specifically, what the scientist did was place accelerometers on the wings of a couple dozen sea birds on the Crozet Islands. The accelerometers measured, more or less, the flapping force and speed of the birds’ wings.

Among the birds studied were wandering albatrosses, which have the largest wingspans of any living birds. Large seabirds like this have often been used as analogies for pterosaurs for their somewhat similar body shapes. Many pterosaurs probably lived in a similar habitat to modern seabirds as well.

Albatrosses fly by riding shifting wind currents, and by flapping their wings when the wind isn’t suitable, or is absent entirely. Sato found that the seabirds he studied have two flapping speeds, a faster speed for taking off, and a slower speed for staying aloft in the absence of wind. He also noticed that, as this flapping speed is limited by the birds’ strength, it decreases in heavier birds with longer wings.

According to the calculations Sato based off of this data, birds (or pterosaurs) weighing more than about 90 pounds would be unable to fly without using wind currents—they simply wouldn’t be able to flap their wings fast enough to stay in the air. There were certainly pterosaurs that size and much smaller, but a lot of flying reptiles were probably a great deal larger than that (a very conservative estimate for the quetzalcoatlus, for example, would have it weighing around 220 pounds).

The article I read on this research doesn’t get into Sato’s hypothesis much more than that, but I’d assume that this means that larger pterosaurs would then also be unable to take off from anywhere other than, say, a cliff face. I wonder if the implication is also that they wouldn’t be doing any flying at all; that medium to large pterosaurs wouldn’t even be gliding on wind currents because, at some point, they’d need to gain some altitude on their own steam.

But, whatever the specifics, them’s fightin’ words, and pterosaur specialists the world over are no doubt sharpening their boot-spikes, and wrapping their fists in chains.

Is it a valid analogy? Maaaaybeeee… But I’m betting against it. There have been some interesting theories lately about how the largest of the pterosaurs may not have flown as much as we used to think, but they don’t imply that they couldn’t fly at all. In fact, the study I’m thinking of would further distance pterosaurs from large seabirds in terms of behavior and their ecological niches (making any analogies a little less apt).

Other scientists argue that in addition to anatomical and physiological differences that should be considered, the atmosphere of the Mesozoic was, on the whole, somewhat denser, and had higher concentrations of oxygen—factors that would have allowed flight for larger, heavier animals. Actually, I recommend checking out the discussion following the article. There are a bunch of explanations of how pterosaurs could have flown, despite what this study suggests. But, if you do go, bring your knives—they’re an angry bunch.

Australian scientists studying albedo--the amount of sunlight reflected off the Earth—have created a flat cardboard kangaroo 105 feet tall. Photographing the image from space will give clues to how the Earth’s atmosphere heats up and cools down.

Oct
14
2007

Fitting that something called a "bore" would be found in Iowa: Photo by NASA.  Minnesota trash-talk by Gene
Fitting that something called a "bore" would be found in Iowa: Photo by NASA. Minnesota trash-talk by Gene

Colliding masses of air over Des Moines, Iowa on October 3 formed waves of clouds known as an undular bore. (Time-lapse video at the link.)

What happened was an approaching thunderstorm plowed into a mass of stable, cold air, like the prow of a ship plowing through the water. This set up huge waves in the air, which rippled over Des Moines. Winds would whip around 180° as the waves rolled by.

Scientists think these types of waves may be more common than we know, and may play a big role in violent weather.

Jul
11
2007

Venus and Mars are alright tonight: They may not teach us much about conditions on Earth, but they provide hours of entertaining temperature conversion!  Photo of Venus (left) from NASA; photo of Mars (other guy) from the Library of Congress.
Venus and Mars are alright tonight: They may not teach us much about conditions on Earth, but they provide hours of entertaining temperature conversion! Photo of Venus (left) from NASA; photo of Mars (other guy) from the Library of Congress.

As Science Buzz's resident global warming skeptic, I've taken a lot of shots at Al Gore over the years. Today, however, I find myself in the unusual position of having to defend him against unfair attacks. Somewhat.

In an editorial last Sunday, Gore stated:

“Consider this tale of two planets. Earth and Venus are almost exactly the same size, and have almost exactly the same amount of carbon. The difference is that most of the carbon on Earth is in the ground - having been deposited there by various forms of life over the last 600 million years - and most of the carbon on Venus is in the atmosphere.

As a result, while the average temperature on Earth is a pleasant 59 degrees, the average temperature on Venus is 867 degrees. True, Venus is closer to the Sun than we are, but the fault is not in our star; Venus is three times hotter on average than Mercury, which is right next to the Sun. It's the carbon dioxide.”

This got a bunch of bloggers to thinking. George Reisman went to a NASA website and found an interesting comparison:

PLANET Venus Earth Mars
CO2 IN ATMOSPHERE 96% 0%* 95%
AVERAGE TEMPERATURE 867˚F 59˚F -81˚F

*Not quite true: Earth’s atmosphere is 0.035% CO2.

So, planets with lots of carbon in their atmosphere can be either broiling hot or icy cold.

(Another writer, Evan Kayne, complained (seventh item) the comparison isn't fair; Reisman didn’t take into account the fact that the atmosphere on Mars is only 1.3% as thick as Earth’s. James Taranto of the Wall Street Journal re-did the calculations, and concluded that frigid Mars still has 34x as much CO2 per cubic foot of atmosphere as the Earth does.)

So far, Al isn't looking too good. But then, blogger David Downing thought he'd discovered another problem. According to the NASA site, Mercury has an average temperature of 452˚ Kelvin, while Venus has an average temp of 726˚ Kelvin. That’s only 1.6 times hotter, a far cry from what Gore had claimed!

Wait a minute. What’s this “Kelvin” scale and why is Downing using it? Well, all temperature scales measure energy. And on the Kelvin scale, 0 degrees means “no energy AT ALL.”

This makes it very easy to compare the energy in different systems. In Celsius, 0 degrees doesn’t mean “zero energy;” it means “the amount of energy in frozen water” -- which may seem chilly to you and me, but at a molecular scale, it’s got plenty of heat. (0 degrees Fahrenheit is apparently the amount of energy in a mix of ice, water, and ammonium chloride.) Comparing 25˚F to 50˚F is tricky, because the scale doesn't stop at 0. As any Minnesotan knows, it goes wayyyyy lower than that!

(It’s kind of like saying “Mike is five years older than me; Vic is 10 years older than me; therefore, Vic is twice as old as Mike.” That would only be true if I were 0 years old. If I were, say, 47, then Mike would be 52 and Vic would be 57, and the differences would be much less impressive.)

So, Downing assumed Gore must have been working in Fahrenheit, and believed that if Venus is 867˚F and Mercury is 289˚F, then Venus is three times hotter. Ha ha, what a silly mistake! I was all prepared to poke fun at Al for this glaring error, until I realized – Mercury isn’t 289˚F. According to NASA, it’s a toasty 354˚F.

So, where did Al get 289˚F? I looked in a bunch of sources -- no one was even close. Wikipedia listed Mercury at a mere 26˚F. (The side facing the Sun broils; the side turned away freezes; this is an average.)

But then I noticed -- 26˚F is 270˚K. And Wikipedia lists Venus at 735˚K . Using the proper Kelvin scale, that works out to 2.7 times hotter than Mercury. Not quite 3 times, but in the ballpark. And, to be fair, Wikipedia gives Mercury a range of temperatures, and “3x hotter” fits comfortably within that range.

So, it turns out Gore was closer to being right than he’s given credit for. He WAS working in the proper Kelvin scale. He was just relying on figures from Wikipedia rather than from NASA.

I don’t know if all this has taught us anything about global warming. But man, have I learned a lot about planetary atmospheres, temperature scales, and math! Thanks, Al!

UPDATE: Evan Kaye had claimed that the atmosphere on Mars is only 2% as thick as Earth's. James Taranto, using figures from the NASA site linked to above, calculated that it is actually 1.3% as thick as Earth's. We have corrected the figure.