Stories tagged Forces of Nature

Feb
04
2011

Dragonfly wing: Its structure is aiding wind-power researchers
Dragonfly wing: Its structure is aiding wind-power researchersCourtesy Mark Ryan
Researchers in Japan are studying the wing structure of dragonflies to help improve how micro wind turbines perform during high winds. Micro turbines are small, affordable energy converters that can be used in both urban and rural settings where giant turbines would be too expensive, too large, and too impractical. Micro turbines can be set up relatively easily in configurations of a single unit or as a bank of several units, and the energy generated can be stored in batteries.

They work on the same principle as the large turbines, but can generate power in wind speeds as low as 4 or 5 miles per hour. One fallback, though, is their generators can get overloaded when hit with high storm winds, producing more energy than the system can handle. Large turbines solve this problem by tilting their propellers - either by computer or otherwise - and adjusting their rotation speed. But that kind of technology just isn’t affordable with micro turbines.

That’s where studying dragonfly wings comes in. Aerospace engineer Akira Obata of Nippon Bunri University in Oita, Japan wondered how dragonflies were able to remain stable in flight at low speeds. He placed a plastic model of a dragonfly wing into a large tank of water laced with aluminum powder and videotaped the flow patterns. He noticed that as the water flow slowed down vortices arose on the wing’s surface that allowed the water to pass over the wing at the same speed, thus keeping it stable. But when water flow sped up the wings aerodynamics performance decreased.

So, Obata developed an inexpensive paper micro turbine with similar “dragonfly wing” bumps on its surface and it did just as he hoped. When air speeds flowing over the turbine wing increased between 15 and 90 mph, rather than speeding up its rotation and overwhelming its battery, the micro turbine curved into a conical shape that stunted rotation and kept power generation low.

New Scientist story
CNBC story on homemade micro turbine
Make your own micro turbine

Jan
31
2011

Leigh and I have safely arrive in Christchurch, preparing for our second trip to Antarctica this field season. We flew down with several folks that will be wintering over on the ice. For some, this is their first trip to the ice ever, for others, this has just become a bit routine.

The weather here is a bit chilly and overcast this evening, with a very nice forecast for the next two days. The forecast for our friends and family back home in KS is not nearly as positive. I guess that all depends on how you look at it though.

It's already been a crazy winter, and now this! I'm not going to lie, there is a part of me that really wishes I was going to be there for this one. I'm obviously a person that doesn't mind the cold weather or snow. Safe travels to everyone back in the Midwest! Stay safe and warm! We'll try to do the same down south.

Pop QUIZ: How would you describe the job of a Petroleum Transfer Engineer?

Nov
17
2010

Longevity record holder Jeanne Calment in 1895: She was only 20 years old and would live for another 102 years.
Longevity record holder Jeanne Calment in 1895: She was only 20 years old and would live for another 102 years.Courtesy Wikipedia
You know, today is Buzz contributor Thor's birthday. I'm not sure how old he is, but I think we're pretty close in age. He may be a little younger than I am. Whatever. It doesn't matter. But if he's like me, he's not just celebrating his birthday, he's complaining about it. Complaining that he just keeps getting older and older. Yeah, yeah, I know. You’re thinking: “Well, isn’t getting older better than the alternative?” Okay, I suppose it is. And I think Thor would agree. But for some life forms, it’s way, way better.

You can see what I mean over at the NOVA website's interesting interactive that goes through a list of several oldest living creatures on Earth. You’ll see that we humans get the short end of the stick, mortality-wise. Our oldest, verified member lived to be 122 years old. She was a French woman named Jeanne Calment who attributed her long existence to eating lots of chocolate and olive oil. From our normal four-score average perspective, it’s not a bad record, but it doesn’t hold a candle to some of our fungal or botanical co-habitants. Some of those have lived for thousands of years. There’s even a genus of water-borne, microscopic creatures known as Hydra that, due to its regenerative capabilities, may have achieved immortality, although all the votes aren’t in on that feat yet.

My personal favorites, however, are the bacterial spores trapped in salt crystals that have been revived and estimated to be about 250 millions of years old! That means they were living back when some Triassic archosaurs were trying to kick-start the Age of Reptiles. They also add credence to the theory that life on Earth may have originated from bacteria-bearing meteor impacts from outer space.

Okay, so it looks like, in the general scheme of things, we humans aren’t that impressive in the long-life department. But it doesn’t bother me too much - and again I'm guessing Thor feels the same way - because with Jeanne Calment’s record of 122 years it could mean we haven’t even reached middle age yet. Happy birthday, Thor!

SOURCE
NOVA site

Nov
04
2010

You think you’re safe from the dangers of the wild just because you live in a city? This video will change your view. It was shot by a guy named Craig Kuberski, who lives within the city limits of St. Paul, MN. I know some of you were hoping you'd get to see a rogue cougar or bear mauling innocent urbanites or eating their pets, but that’s not the case here. It’s just a couple of bucks on the town and in a rut trying to catch some city girls' attention.

Rutting period is the mating season for many ruminants, (i.e. mammals like moose, caribou, bison, and deer). The rut is set-off by the shortening of daylight hours during autumn and in the case of white-tail deer (Odocoileus virginianus - which I’m pretty sure these are) can last for one to three months. During that time, male deer get all goofy and twitterpated, rubbing their antlers against trees, rolling in the dirt or mud, or battling each other – as seen in this video. Rutting season is the best time to hunt for them, and the easiest time to hit them with your car, although I don’t advise you do the latter.

As you may notice, Mr. Kubinski posted two buck fever videos on YouTube. I’ve only used the second here because it’s the better of the two, focus-wise, But if you’d also like to watch Part I, there you have it. KARE 11 also ran a story on it.

Sep
03
2010

WHY?: Clouds are hard to model, so let's show them who's boss.
WHY?: Clouds are hard to model, so let's show them who's boss.Courtesy Paige Shoemaker

Next time you look at the clouds, shake your fist and yell at those jerks for making our lives difficult. You might look crazy, but somebody needs to tell those fools.

While it's relatively easy to model temperature changes over the last century thanks to detailed records, clouds are more tricky to understand because we don't have a similar history of cloud observations, and also because they are ornery. So in order to understand how clouds work, scientists are building a body of evidence to model cloud behavior and help show how clouds will impact our weather as well as our climate in the future. I believe they also plan to show those clouds who is the boss of them.

Hurricane help!
Like a child running loose in a toy store, hurricanes have always been difficult to predict because they can unexpectedly change direction. This confounds plans for evacuation, leading some people to leave areas that are never hit, leading others to stay put and potentially face nasty weather because they don't trust the meteorologist, and leading meteorologists to keep Advil in business. But since the 90s, our ability to predict where hurricanes will make landfall has become twice as accurate. This new prescience is due to the development and use of more accurate models of how clouds work, which is in turn due to better understanding of cloud dynamics and faster computers. How about that, punk clouds?

Intensity, however, remains elusive to model. (Shh, don't let them know we have a weakness!)

Go home, son: If wily Earl thought he could outsmart the meteorologists, then he's in for a schoolin'.
Go home, son: If wily Earl thought he could outsmart the meteorologists, then he's in for a schoolin'.Courtesy NASA

"While we pride ourselves that the track forecast is getting better and better, we remain humbled by the uncertainties of the science we don't yet understand," Schott said. "This is not an algebra question where there's only one right answer."

-Timothy Schott, tropical cyclone program leader for the National Weather Service in Silver Spring, Md.

Hurricane Earl
Despite being a "forecasting nightmare," Earl ended up hitting about where it was predicted to go. This means that the right people have been evacuated to avoid injury and fatality. That's right, stick your tail between your legs, Earl.

Connecting to climate
Short-term events such as hurricanes and other storms are difficult to predict, but climate change is a whole other world of uncertainty--again, thanks to those uncouth clouds. Climate scientists are developing new tools, such as satellite technologies that show how much light different cloud types reflect and models that demonstrate localized cloud processes. These approaches look specifically at certain groups of clouds and their patterns of change to add detail to older, larger models that look at climate over larger scales.

Booyah!: Climate computer nerds prevail.
Booyah!: Climate computer nerds prevail.Courtesy Nic McPhee

The problem with the older models is that they have a low resolution that doesn't accurately represent clouds because the clouds are smaller than they can show. Think of it like Google maps--at the beginning, you're looking at the entire planet, or a whole continent--this is similar to older, low-res climate models. The new models are like zooming in on a city--you can see bus stops, restaurants, and highways. But you have to zoom out to see how these small pieces relate to the larger surroundings. In a similar way, the new high-res models are helping to inform older models--this type of work is called multiscale modeling.

Researchers at the Center for Multiscale Modeling of Atmospheric Processes (CMMAP) are developing this exact type of model. You can read about their advances here. This work is important because it brings insight into questions about whether clouds will reflect or trap more sunlight, which can have a big impact on the rate of global warming. It also helps us understand whether geoengineering projects that alter clouds will really have the intended effect. Plus it's just one more way we can pwn clouds.

Sep
02
2010

Electricity in the air: Some of our energy needs may someday come from the atmosphere.
Electricity in the air: Some of our energy needs may someday come from the atmosphere.Courtesy wvs (Sam Javanrouh)
In a paper delivered at the 240th National Meeting of the American Chemical Society in Boston, a researcher envisioned a time in the not-too-distant future when houses and buildings outfitted with the proper equipment would be able gather electric energy stored in humidity in the atmosphere that could be used to fill a community’s electrical needs.

The concept isn’t new; electrical wunderkind Nikola Tesla had a similar idea more than a century ago.

Science has long sought the answer to how electricity builds up and discharges in the atmosphere, and whether the moisture in the atmosphere could even hold an electrical charge. But Fernando Galembeck, a professor at Brazil’s University of Campinas, claims he and his research team have successfully shown that it can, and by using special metal conduits to collect that electricity, it could allow homeowners and building managers to gather and store the electricity as an alternative energy source.

”Just as solar energy could free some households from paying electric bills, this promising new energy source could have a similar effect,” Galembeck said. He terms the new method “hygroelectricity” which means “humidity electricity”. Galembeck's research could also add to our understanding of how thunderstorms form.

In their laboratory experiments, Galembeck’s research team created a simulated atmosphere densely saturated with water (humidity), which they seeded with silica and aluminum phosphate, two chemical compounds commonly found in air. As water droplets formed around the tiny, airborne chemical substances, the researchers noticed the silica took on a negative charge while the aluminum phosphate droplets held a positive charge. The charged water vapor readily condenses upon contact with surfaces such as a cold can of soda or beer, and on the windows of air-conditioned buildings or vehicles. In the process, energy is transferred onto the contact surface.

“This was clear evidence that water in the atmosphere can accumulate electrical charges and transfer them to other materials it comes in contact with,” Galembeck said.

Just as solar panels convert energy from sunlight into a usable power source, the researchers think water vapor in the atmosphere could someday be harvested for its hygroelectric energy. The rooftops of buildings in regions of high humidity and thunderstorm activity could someday be fitted with special hygroelectric panels that would absorb the charges built up in the humid atmosphere and funnel the energy to where it can be utilized, and at the same time reduce the risk of lightning forming and discharging. The technology would be best suited to regions of high humidity, such as the tropics or the eastern and southeastern U.S.

SOURCES
ScienceDaily story
Wired story
Green Diary story

Thunderstorm over Lake Harriet in Minneapolis; Could this be a new source of energy for the Upper Midwest?

Aug
28
2010

T-rex could run, but he couldn't hide: More than one asteroid impact may have wiped out non-avian dinosaurs.
T-rex could run, but he couldn't hide: More than one asteroid impact may have wiped out non-avian dinosaurs.Courtesy Mark Ryan
The meteor that created the Chicxulub Crater in Mexico's Yucatan Peninsula may have not been the only one responsible for the extinction of non-avian dinosaurs 65 million years ago. "Fern spike" evidence in another similarly-aged crater found in the Ukraine indicates at least two large impacts took place within a few thousand years of each other. Concentrations of fern spores are commonly found in the mud that fills in impact craters. The Boltysh Crater contains two layers of spores within three feet of each other, indicating not one but two impacts.

"We interpret this second layer as the aftermath of the Chicxulub impact", said Simon Kelley, co-author of the study, and professor of Isotope Geochemistry at the Open University.

Both the Chicxulub and Boltysh bolide events could have been part of a meteor shower that hit Earth at the end of the Cretaceous. The study appears in the journal Geology.

SOURCE and INFO LINKS
BBC story
The K-T Extinction event

Aug
20
2010

Beating the heat in Duluth, MN: Fearless swimmers take advantage of Lake Superior's record temps.
Beating the heat in Duluth, MN: Fearless swimmers take advantage of Lake Superior's record temps.Courtesy Mark Ryan
Last week, Lake Superior, which is bordered by Minnesota, Wisconsin, Michigan, and Ontario, Canada, recorded its highest average surface temperature ever, a balmy 68.3°F. People seeking relief from a very hot summer have been flocking to the shores and beaches and actually swimming in the lake! That is so unlike the Lake Superior I remember growing up in Duluth. Sure, we liked to spend a day on the sand beaches of Park Point or lounging on the rocky outcrops along the North Shore but swimming was usually not an option. On average, Lake Superior’s overall temperature is barely above freezing (39 °F), and back then it seemed you couldn’t even wade in ankle-deep without having your breath sucked out of your lungs and thinking your feet had fallen off. Standing knee-deep in the water for even a short time was unbearable and a true test of endurance. And for guys, going any further was just plain crazy, unless you wanted verifiable (and excruciating) proof of Costanza’sTheory of Shrinkage.

Those hell-bent among us would sometimes make a mad suicide dash across the burning sands and actually dive into the frigid waters only to set off the mammalian diving reflex and cause their vital organs to start to shut down. Their only hope was if the lifeguards were watching and were properly certified in CPR.

Temperature ranges on Superior have been recorded for more than three decades. In recent years, the normal average surface temperature for Lake Superior during the month of August has been only 55°, so this dramatic rise in the average is unusual. As expected, many people are quick to point a finger at global warming as the cause for the rise. That’s not a bad guess considering the National Oceanic and Atmospheric Administration (NOAA) just proclaimed the year 2010 as the hottest on record, globally.

But physicist Jay Austin at the University of Minnesota-Duluth’s Large Lake Observatory has been closely tracking the lake’s surface temperatures, and predicted the record high back in July. He says the warm water this summer is at least partially due to a recent El Niño event that had an unusual effect on the lake this past winter.

“2009 was a very strong El Niño year,” Austin said. “And that El Niño year led to a year at least on Superior where there was very little ice.”

That lack of ice led to a quicker and earlier warm up of Lake Superior’s surface waters. The other Great Lakes showed similar increases in their average warm temperatures as well. Although ice usually forms on the lake surface during the winter months, Lake Superior rarely freezes over completely. The last time was in 1979.

The following video illustrates the contrast between last winter and the one prior to that. Each day on their Coast Watch website, NOAA posts 3 or 4 photographs taken by a satellite in geosynchronous orbit above Lake Superior. Early in 2009 I began collecting the images regularly thinking they could come in handy for a future Buzz story such as this. From March 2009 to May 2010 I collected something like 1100 satellite photos. Edited together, they make for an interesting time-lapse video that illustrates the weather patterns over the big lake from one winter to the next. At the start of the video (March 2009) ice-cover is apparent over much of the lake and can be seen building then melting away as the spring thaw brings warmer temperatures. But later in the video, as summer passes into fall and fall into winter, no ice appears at all over the expanse of the lake’s surface. Other than that I don’t know how informative the time-lapse ended up being but it’s certainly interesting to watch, particularly the wind and cloud patterns seen flowing off the lake starting in late January 2010.

"This year is just tremendously anomalous," Austin said. "This year ranks up there with the warmest water we have ever seen, and the warming trend appears to be going on in all of the Great Lakes."

The big question is what effect these warmer temperatures have on the lake’s ecology? Austin admits it’s hard to say.

"Fish have a specific range of temperatures in which they like to spawn," he said. "It may be that for some fish this very warm year is going to be great for them, but for others, like trout which are a very cold-adapted fish, it's not going to be great."

One problem for the trout could be that scourge of the Great Lakes, the jawless sea lamprey. Lampreys are invasive parasites and attach themselves to lake trout and live off their blood. It’s unknown what changes, if any, the warmer waters will have on their life-cycle. They may lay eggs faster and in larger quantities, increasing their populations, and their impact on the trout species.

Lake Superior has probably passed through its peak time for temperature this summer so more than likely the 68.3°F record will stand for the rest of the year. If you want to keep track you can go to the Michigan Sea Grant website where you can follow all the Great Lakes’ daily surface temperatures. But who knows? This summer may not be the height of the 30-year warming trend. Let’s see what next year has in store.

Personally, I’m concerned these warm water temperatures will spoil us. Being able to endure extremely cold temperatures is a Minnesota tradition, and helps build character. It makes you tough and able to withstand all sorts of adversity as well as the harshest of elements. Which brings to mind the time when my wife (then girlfriend) and I were in Glacier National Park and decided to go for a swim in St. Mary’s Lake. There were only a few other people goofy enough to be swimming in the glacial lake at the same time. It didn’t surprise us to learn they were all from Minnesota.

We were so proud of ourselves.

SOURCES and INFO
Minnesota Public Radio story
Lake Superior facts
More about Lake Superior
Great Lakes info

Aug
16
2010

Another tidal generator: But this one is hiding underwater. This is why I didn't know what they look like.
Another tidal generator: But this one is hiding underwater. This is why I didn't know what they look like.Courtesy Fundy
Along with wind and solar, harvesting power from tidal forces comes up a lot in discussions of alternative energy sources.

Was that a horrible sentence? I think it was. What I meant to say is this: we can generate electricity from tides, and lots of it. "Tidal power" is often brought up alongside solar power and wind power, but while I can easily picture windmills and solar panels, I'm not always sure what sort of device we'd use to harness the power in the tides.

This sort of device! For those of you too afraid to click on a strange link (who knows... I could be linking to an image like this!), the article depicts something that looks sort of like a thick, stubby windmill, with blades on its front and back. It's a tidal turbine, and at 74 feet tall and 130 tons it's the world's largest. It should be able to supply electricity to about 1,000 households. Pretty impressive.

Tidal turbines, apparently, are so productive because water is so much denser than water, and so it takes a lot more energy to move it. An ocean current moving at 5 knots (that's a little shy of 6 miles per hour, for the landlubbers) has more kinetic energy, for example, than wind moving at over 217 miles per hour.

At least according to that article, the United States and Great Britain each have enough tidal resources (areas where this kind of generator could be installed) to supply about 15% of their energy needs.

More info on the tidal turbine, which I am calling "the Kraken," because it's big, underwater, and will occupy your mind for only a very short time.

Aug
11
2010

Petermann Glacier ice island: Map supplied by Andreas Muenchow.
Petermann Glacier ice island: Map supplied by Andreas Muenchow.Courtesy Public domain
A massive chunk of ice - 100 square miles of it – broke away from Greenland’s Petermann Glacier last week. The ice island is about 500 feet thick and contains enough fresh water to supply our entire nation’s tap water demands for 4 months and then some.

Just what the free-floating slab of ice will do next is anyone’s guess. Some scientist, such as Andreas Muenchow, a professor of ocean science and engineering at the University of Delaware are concerned it could get wedged in by actual islands dotting the Nares Strait between Greenland and Canada and jam up shipping lanes there.

"The newly born ice island may become land-fast, block the channel, or it may break into smaller pieces as it is propelled south by the prevailing ocean currents,” Muenchow said. “From there, it will likely follow along the coasts of Baffin Island and Labrador, to reach the Atlantic within the next two years."

A similar, huge slab of ice broke away from Greenland’s Ward Hunt Ice Shelf in 1962, and pieces of it became stuck in channel islands in the Nares Strait which is located about 600 miles south of the North Pole.

Muenchow has been keeping a watchful eye on the Petermann Glacier for the past several years and said he was expecting a calving to take place because the ice shelf had been growing. However, he wasn’t expecting one so large.

Although recent trends show a rise in global temperatures, Muenchow stops short of blaming the ice slab on climate change. "Nobody can claim this was caused by global warming. On the other hand nobody can claim that it wasn't," he said.

The Petermann Glacier is an ice shelf situated in northern Greenland covering an area of about 40 miles. The new ice island amounts to about twenty-five percent of the ice sheet. The following video from last summer shows why scientists were expecting last week’s event.

SOURCES
CNN story
Canadian Ice Service page
Story on Yahoo
Nares Strait Meteorological Modeling page