Posts by: Margaret Harris

Bad weather? Blame Santa

By Margaret Harris in Chicago

If you’re fed up with floods in England, sick of snow in the US or mystified by mild temperatures in Scandinavia, blame it on Santa Claus. That’s the message coming from atmospheric scientist Jennifer Francis, whose “Santa’s revenge” hypothesis suggests that the weather weirdness that we’re currently seeing at middle latitudes could be linked to recent warming in the Arctic.

Francis’ theory begins with the polar jet stream, the high-altitude “river of air” that flows over parts of the northern hemisphere. This jet stream owes its existence to the temperature differential between the Arctic region and middle latitudes: because warm air expands, that temperature differential produces a “hill” of air with (for example) England at the top and Greenland at the bottom. The Earth’s rotation means that air doesn’t flow straight down this hill; instead, it curves around, producing the west–east flow seen in animations like the one in this video from the NASA Goddard Science Visualization Studio.

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Burning the midnight gas

Satellite image showing dots of light from flared natural gas in North Dakota

The light from natural gas flares burning in North Dakota’s Bakken oil field can be seen from space. (Courtesy: NASA Earth Observatory)

By Margaret Harris in Chicago

The environmental risks of shale-gas production are real, but the things people worry about most aren’t necessarily the ones that cause the most damage. That was the message of this morning’s AAAS symposium on “Hydraulic Fracturing: Science, Technology, Myths and Challenges”, which featured talks on the social implications of hydraulic fracturing as well as the risks of water and air contamination.

Hydraulic fracturing, or “fracking”, involves drilling a well and filling it with a high-pressure mixture of water and other chemicals. These high pressures cause nearby rock formations to fracture, releasing trapped oil and gas. According to the first speaker, energy consultant David Alleman, fracking and horizontal drilling have “revolutionized the energy picture in the US”: a few years ago, the country imported 60% of the oil it consumed, but today the figure is just 30%.

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Eye-catching exhibits

By Margaret Harris, Physics World, in Washington, DC

No trip to the AAAS meeting would be complete without a tour of the exhibit hall, which for the past two days has been buzzing with visitors to “Family Science Days”, a public outreach-oriented event running in parallel with the more technical seminars.

One of the most eye-catching exhibits was the National Oceanic and Atmospheric Administration’s Science on a Sphere, which pretty much does what it says on the tin. The Sphere is the brainchild of Alexander McDonald, director of NOAA’s Earth Systems Research Laboratory, and there are now over 250 datasets that can be displayed on it. In this photo, it’s illustrating the shock waves that spread around the globe after the Boxing Day tsunami of 2004, but I also saw depictions of ocean currents, aeroplane flight paths, global temperatures and the past week’s weather. According to exhibitor Jana Goldman, there’s even one in a science fiction museum in Seattle, Washington that displays the (hypothetical) features of a (fictional) alien planet — so it’s definitely a versatile beast!

Another exhibit that got a lot of traffic was the US Department of Energy’s set of bicycle-powered light bulbs, which is designed to teach kids (and maybe some adults) about the differences between voltage and current, and to demonstrate in a very physical way how much power it takes to light up an incandescent 50W bulb compared to fluorescent and LED bulbs. The young gentleman in this photo, for example, was having real trouble getting the incandescent bulb to give off any light, but despite being a little too short for the pedals, he managed the LED bulb just fine.

For the bigger kids, exhibitor Steve Eckstrand keeps a 12V, 300W hairdryer on hand. “They can usually get the 50W bulb working just fine, and one girl did manage to pedal hard enough to get a faint glow out of the 100W bulb,” he says. “But nobody can do more than get the hairdryer sort of gently warm.”

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