Stories tagged Earth and Space Science

Sep
13
2010

Double rainbow
Double rainbowCourtesy Joe
Double rainbow close-up
Double rainbow close-upCourtesy Joe
This past July I was Up North at the family cabin in northern Minnesota and saw this amazing rainbow. It by far and away was the brightest rainbow I had ever seen. And, in addition, there was this second, fainter rainbow, to the right (seen in this picture).

I was very curious about this second rainbow and wanted to see how that was possible. And where did I learn my answer? Right here on Science Buzz thanks to mdr! Here's the scoop from his blog on this topic from a few years ago:

Basically, rainbows are the result of sunlight being once reflected and twice refracted by raindrops. Certain conditions are required. First and foremost, the viewer needs to be located between the sun and rain clouds. A ray of sunlight enters an individual drop of water and is refracted (bent) as it enters, then reflected from the back of the drop, and refracted again as it exits the drop. The refractions cause the white sunlight to divide into separate colors. Each color refracts in slightly different amounts, red the least, and violet the most. A particular raindrop will reflect red light because it is positioned at just the right angle from your eye (42°). This is known as the “rainbow ray”. Another droplet located at a slightly different position will reflect blue light to your eye. Now multiply this by the innumerable suspended water droplets that make up a rain cloud, and you have a rainbow.

The main colors in a primary rainbow will have red at the top followed by orange, yellow, green, blue, indigo, and violet. An easy way to remember the order is to note that the first letter of each color spells out the name ROY G. BIV.

The rainbow I witnessed had a second, fainter rainbow just above the first. This is the result of some light being reflected twice, and at a higher angle. The colors in a secondary arc are reversed with red on the bottom and violet on top.

Thanks mdr!

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
31
2010

This kid is sitting on a fortune!: That balloon will put him through college, assuming he doesn't blow it all first on candy and blackjack.
This kid is sitting on a fortune!: That balloon will put him through college, assuming he doesn't blow it all first on candy and blackjack.Courtesy Lars Plougmann
Y’all ever see Mad Max? Or Mad Max 2: The Road Warrior? Or even Mad Max 3: Beyond Thunderdome?

Some of you surely have, and I salute you. For the rest of you, the short description is this: a handsome young Australian actor, who we should just assume is now dead, played a lone wanderer, drifting across a post-apocalyptic wasteland. During the course of his adventures, he meets Tina turner, a really weird looking pilot (twice?!), a grunting, boomerang-throwing feral child, a man named Toe-cutter, and an awesome giant/little person team (sort of like Jordan and Pippen, but more inclined towards stranglings). It’s all very exciting! But the most important part of the Mad Max trilogy is this: he lives in a world without gas. Everybody was so busy blowing each other up that they forgot to be careful with their oil, so by the time Max rolls around, people are freaking out trying to get a few more drops of “the precious juice” for their dune buggies and flame throwers.

And so we come to our news item, and this afternoon’s future-dread focus: helium. If you look at the Mad Max summary and pretend “gas” refers to helium gas instead of gasoline, and if you replace “dune buggies” with “scanning equipment,” and “flame throwers” with “party balloons,” it’s a pretty decent analogy.

See, we’re running out of helium. And when it’s gone, it’s gone forever.

The above statement brings to mind two points (at least for me):
1) No we aren’t. Shut up.; and
2) Even if we are running out of helium, who cares? I can fill up my party balloons with air, or Cheesewhiz, or something.

If you read the article linked to above (or one of the many articles on the subject that came out last week), you’ll find that the answer to point 1 is, yeah, we kinda are, and the answer to point 2 is, it’ll be sad to see floating party balloons go, but they’re the least of our problems. It’s all dune buggies and flame throwers from here on out.

The problem is that helium is non-renewable. We talk about oil being non-renewable, but helium is even more non-renewable. See, helium only comes from fusion reactions (hydrogen atoms slamming together to form heavier helium), or from radioactive decay (heavier elements breaking apart at the atomic level to form lighter helium). Hydrogen fusion only happens in stars (scientists are trying to replicate it as an awesome source of nuclear energy, but don’t hold your breath), so all of the helium on our planet comes from underground, where gases from radioactive decay have become trapped.

We’ve got a nice big planet here, and we’ve got lots of helium, but we’ve just been farting it away, and once helium is released into the atmosphere, it’s gone to us for good. And we’re currently farting away helium at such a tremendous rate that the gas could be all but unavailable within a couple generations. The reason for this is that it’s actually official policy to fart away helium. (More or less.)

A huge portion of the world’s helium has been mined from the American Southwest, and for a long time we were actually pretty good at storing it—we pumped it back underground into a huge system of old mines, pipes and vats near Amarillo, Texas, in a facility called the US National Helium Reserve. We stored the helium because it was strategically useful to the country—it was vital for rocket operation during the Cold War. But in 1996, a law was passed requiring the helium to be sold off, all of it, and by 2015. I’m not totally clear on the reason for the law. I suppose the idea was that the Cold War was over, and by selling the helium, the US National Helium Reserve could be paid for (sort of a Gift of the Magi kinda thing, but whatever.) Congress, however, decided that the price of the sold helium would remain the same until it was all gone, so even as available helium became scarce, it would never be more expensive.

This broke the law of supply and demand, and having this vast, vast supply of helium go on sale for cheap meant that all the helium in the world had to be cheap too. Helium has become so cheap, in fact, that there’s no economic incentive for recycling it—recapturing it after use is so much more expensive than just buying new helium, people have just been letting the used helium drift away, where we’ll never be able to reclaim it. Normally, when a resource becomes more scarce, its price will go up, and people will be better about using it. (For an example, see gas prices and fuel efficiency in cars.) Not so with helium, thanks to that 1996 law. And pretty soon, say some scientists, we’ll be running out of the precious gas.

The “precious” part is there because helium is useful for a lot more than party balloons. (Although they’re ok too.) The properties of helium make it an excellent coolant for medical scanning equipment, and the sort of detectors used in super colliders. It’s also used in telescopes, diving equipment, rockets (NASA is a huge user—and waster—of helium), fusion research, and airships. (And don’t laugh about that last one—as the price of fuel goes up, the prospect of eventually moving cargo with lighter-than-air aircraft, like blimps and zeppelins, is becoming more likely. And hydrogen is a little bit too explodey to be a great alternative lifting gas.)

Helium is so desired, and is being wasted at such a rapid rate, claims Robert Richardson (a Nobel Prize-winning physicist, whose research was on helium), that a single helium-filled party balloon ought to cost about $100.

That’s right: $100. It’s that, or we keep going until there’s no helium left. And then... it’s Thunderdome. You know the rules—there are none.

Aug
31
2010

This is not climate: It is weather. Also, it is breakfast.
This is not climate: It is weather. Also, it is breakfast.Courtesy Lori Geig
Well, no, I won’t literally shout it into your brain. First of all, I’m writing this in the near past, and it’s difficult to shout in this medium anyhow. Also, even if we were right next to each other at the same time, I’d really be shouting into one of your ears, or possibly into your face. To shout into your brain, I’d need some sort of saw, or a hammer, and I’d definitely need your cooperation. (I’m just that kind of guy.) So the shouting thing is out.

But it’s really important that you understand the difference between weather and climate, or folks are going to take advantage of your confusion. They’ll do it with op-eds and obnoxious little bumper stickers instead of with a hammer, but it will still be unpleasant in the end.

So here’s the thing: weather and climate are not the same.

See, you may say to yourself, “I know the difference between weather and climate. I’m smrt!” And you may very well be smert, but there’s a decent chance that you still let weather fool you into thinking it’s climate. As this article in the NY Times points out, plenty of samart people still confuse the two concepts, or at least use one (weather) to make points about the other (climate).

Let’s be different. Let’s be truly smaret people, and get this cleared up once and for all. Weather is not the same thing as climate.

Weather is day-to-day, climate is year-to-year, or decade-to-decade, or century-to-century. Weather is immediate, and we feel it acutely, so it weighs on our minds. But it isn’t climate, which is so long-term that even very smar people tend to miss the point.

The East Coast had a frigid snowy winter, so global warming must be myth, right? But the Midwest and Russia have been having a hot hot summer, so we must be in the burning grip of global warming, right? No. If either is the case, a cold winter or a hot summer isn’t the evidence for it.

Back in the year 1991, there was a blizzard on Halloween. If was off the hooook! I was a jawa, or something, and I trick-or-treated my way through about two and a half feet of snow. Crazy, right? But does that crazy Halloween blizzard mean that October is a very snowy month in Minnesota? Of course not! Who would even think that?

What if we (Minnesotans) got a couple solid weeks of rain right now, at the tail end of summer? That would be a damp way to spend the Labor Day weekend. But would it mean that Minnesota is on its way to becoming a rainforest. No, no it wouldn’t. A rainy couple weeks, or even a whole rainy summer, is weather. Climate is weather (temperature, wind, humidity, atmospheric pressure, precipitation, etc) averaged out over years and years. I’m sorry if your birthday was ruined by a freak firestorm, but that doesn’t have a thing to do with climate, so stop making that demonstration sign with a picture of your cake melting.

Maybe it seems obvious, but we still tend to use weather as a substitute for climate even when we think we understand it. Consider the concept of “Global Warming’s Six Americas.” A report from Yale University has found that people can be placed into six groups regarding their feelings on climate change: alarmed, concerned, cautious, disengaged, doubtful, or dismissive.

People who fall into the extreme categories, the freaking-out “alarmed” and the denying “dismissive,” typically aren’t swayed by day-to-day weather—they might use it to further their own arguments, but they (rightly) don’t let it affect their perceptions of long-term climate behavior.

Everyone else, the various shades of undecided, however, is influenced by the local weather, often subconsciously.

Say what?! Clever people that we are, we still allow the wrong evidence to influence our opinions on huge, important issues?! We have to be smaearter than that! So whenever your jerky aunt or your shrill uncle are trying to tell you that the Christmas heat wave or the frosty July mornings are evidence for or against global warming, run the information through your own brain, and when your brain tells you that you need to consider years and years worth of information before you can make that call, you can tell them to shove it.

Of course climate is made up of weather—lots and lots and lots of weather—but, as an author of a report on the subject puts it, making generalizations about climate based on weather “is like asserting how the economy is doing by looking at the change in your pocket. It’s relevant, but not that relevant.”

I like to think of it another way, too. Like, in Home Alone, just because Kevin Mcallister’s family called him “such a disease,” and left him home alone that one time, it didn’t mean that they didn’t really love him. To actually switch to a climate of non-love, the Mcallisters would have to call Kevin a disease every day for years and years, and maybe even stop feeding him.

Or just because Hulk Hogan opened Pastamania in 1995, it would be a mistake to say that the nation was in a climate of true pasta-love, let alone pastamania. Far from it.

To say the climate is changing, or not changing, you have to look at the weather data over many years. So do that, instead of forming opinions on whatever is bugging you on a particular day. Don’t be a chump. Be smart.

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
03
2010

Aurora borealis above Lake Harriet in Minneapolis, MN: The white streak visible in the lower right of the timed exposure is an aircraft taking off from the Minneapolis-St. Paul airport.
Aurora borealis above Lake Harriet in Minneapolis, MN: The white streak visible in the lower right of the timed exposure is an aircraft taking off from the Minneapolis-St. Paul airport.Courtesy Mark Ryan
Old Sol could be stirring up the atmosphere this evening with a display of northern lights (aurora borealis). Scientists have recorded a significant burst of plasma shooting from the Sun’s surface that could mean we earthlings are in for a light show tonight or early Wednesday morning. The solar wind particles are headed right toward us, and when they reach the Earth’s magnetic field they’ll interact with atoms of nitrogen and oxygen in the atmosphere and - hopefully - produce glowing sheets and fingers of green, red, blue, or even yellow in a wonderful display in the northern skies. The southern hemisphere experiences the same phenomenon but down there it’s known as the aurora australis (southern lights).

Lately, here in the Twin Cities, the air has been supersaturated with humidity so I don’t know how crisp a view we’ll get but it could be worth stepping outside tonight to see what’s up.

SOURCE and LINKS
CNN.com report
Univ. of Alaska’s Geophysical Institute Aurora Forecast page
Michigan Tech’s Aurora page
Solar flares

Jul
30
2010

A new record hail stone fell on 23 July 2010 near Vivian SD!

It is 8-inch in diameter hail stone and weighs 1.9375 pounds.

The old record heaviest U.S. hailstone was a 1.67-pound found near Coffeyville, KS on Sep. 3, 1970. The old record for the largest diameter hailstone was 7 inches found in Aurora, NE on June 22, 2003. This Aurora, NE hailstone still holds the U.S. record for circumference: 18.75 inches. The Vivian, SD hailstone circumference was only 18.5".

Here is a photo of the stone

Hail is precipitation in the form of large balls or lumps of ice. Hailstones begin as small ice particles that grow primarily by accretion. The production of large hail requires a strong updraft that is tilted and an abundant supply of supercooled water. Because strong updrafts are required to generate large hailstones, it is not surprising to observe that hail is not randomly distributed in a thunderstorm; instead it occurs in regions near the strong updraft. Supercell thunderstorms, in which the strongest updrafts are created with help from the mesocyclone, often produce the largest hail.
Eventually, though, the weight of the hailstone overcomes the strength of the updraft, and it falls to earth. The curtain of hailstones that falls below the cloud base is called the hailshaft. These regions are often said to appear green to observers on the ground, although recent research suggests that heavy rain as well as hail can create this optical phenomenon. As the storm moves, it generates a hailswath, a section of ground covered with hail.

Hailstorms can severely damage crops, automobiles, and roofs. Sometimes the swath can be so big you can see it on the ground from a satellite

Jun
23
2010

So, this spacecraft that was launched over seven years ago to collect a sample off an asteroid is back? I didn't even know it had left! I am way out of the loop on the activities of the Japan Aerospace Exploration Agency (JAXA) and if this mission is any example, they are doing some sweet stuff.

A Light in the Sky: Hayabusa streaked across the sky through the clouds as it re-entered Earth’s atmosphere over the Woomera Test Range in Australia. In Kingoonya, the spacecraft’s re-entry was visible to the human eye for 15 seconds.
A Light in the Sky: Hayabusa streaked across the sky through the clouds as it re-entered Earth’s atmosphere over the Woomera Test Range in Australia. In Kingoonya, the spacecraft’s re-entry was visible to the human eye for 15 seconds.Courtesy NASA/Ed Schilling
was launched on May 9, 2003 with the intent of it flying to an asteroid, photographing the bejesus out of it, then "landing" on it, collecting a sample and finally returning to Earth. And it did make it to the asteroid and back - returning to Earth on the 13th of June.

Hayabusa did have some troubles along the way – losing a miniprobe to deep space, the failure of two reaction wheels, the failure to properly land and collect a sample (though a sample may still have been obtained)… It was not a flawless mission, but to achieve what they did is no small feat - pretty amazing if you ask me.

Here are some links to learn more.
The JAXA main site.
Hayabusa JAXA mission page.

Jun
17
2010

NCED researchers studying delta dynamics in coastal Louisiana
NCED researchers studying delta dynamics in coastal LouisianaCourtesy National Center for Earth-surface Dynamics
The Mississippi River has turned out to be a big, muddy, silent hero in the fight to save Louisiana's wetlands from the oil spill.

It turns out that many scientists believe that the flow of fresh water from the Mississippi River into the Gulf of Mexico has thus far kept the oil slick offshore and out of wetlands.

Guerry Holm, a researcher with the National Center for Earth-surface Dynamics (NCED) tells me that the flow of the Mississippi River has been at a relatively high stage for the past two months and that the river's high volume of freshwater has acted as a hydrologic barrier, keeping oil from moving into the Mississippi Delta wetlands from the sea. Holms is now studying how two river characteristics—the slope of the water surface from the river delta to the sea and the time it takes water to move through a wetland to the sea—help mitigate oil contamination of the wetlands.

Holm is collaborating on the research with NCED Principal Investigator Robert Twilley, who is also busy addressing an immediate concern: the flow of the Mississippi tends to drop seasonally, starting in June. If that happens and Mississippi water flow into the delta decreases, Twilley, Holm, and others worry that oil will reach more of the wetlands sooner.

To address these concerns, some area scientists are proposing to shift the flow of water between the Mississippi and a river in Louisiana it feeds called the Atchafalaya. Twilley supports the idea: "We've been in conversation with U.S. Army Corps of Engineers and the state [of Louisiana] about how to manage the river as a protection system," Twilley reports.

Unfortunately, the river flow adjustments may be difficult to accomplish for political reasons. The diversion structure used to control flow between the Mississippi and Atchafalaya Rivers is controlled by Congress. Earlier proposals to send more water down the Mississippi have been met with resistance.

Jun
15
2010

Internal BP documents were released today that seem to highlight decisions by the company to forgo safety precautions in favor of saving money and cutting time in drilling the now-leaking oil well. One of the documents, an email message from an engineer working on the project, refers to it as a "nightmare well," language that the press has really picked up on.

I'm hesitant to fixate too much on a phrase like "nightmare well," because the hyperbolic language used in informal emails isn't always super helpful if taken literally (e.g., "It smells like someone microwaved a goat in the break room. I'm gonna die. If I find out who did that, I will challenge them to a knife duel, ala Steven Seagal and Tommy Lee Jones in Under Siege. The first Under Siege, I mean.") But it does seem like the drilling of that well wasn't the best run operation, to say the least. Hopefully the investigation will determine the extent of BP's responsibility for the accident that caused the leak (or, possibly, the lack thereof).

The documents will very probably be brought up during Tony Hayward's (the CEO of BP) testimony to congress later this week. Should be interesting.