It’s the time of year when bright curtains of colored light –auroras –dance across the northern sky, especially between 60 and 72 degrees north and south latitude. Aurorae, named for the Roman goddess of dawn, are a natural phenomenon occurring when charged particles, mostly electrons from the sun, enter the earth’s atmosphere where they are directed toward the polar regions by the Earth’s magnetic field. As these particles enter the upper atmosphere, they collide with other atoms and molecules. During the collision, some energy is transferred to the atom or molecule which becomes excited and re-emits the energy as light as it returns to a non-excited state.

The beautiful light displays are called aurora borealis (Boreas is the Greek god of the north wind) in the northern hemisphere and aurora australis (the Latin word for from the south) in the southern hemisphere. Although aurorae happen year-round, they are usually more visible in winter because of long periods of darkness.

In simple terms, aurora intensity and frequency depends on the solar wind, the stream of charged particles emanating from the sun’s upper atmosphere. More solar wind means more charged particles that enter the earth’s atmosphere which means more aurorae. Sunspots, which are temporary, appear as dark areas on the sun’s surface and amplify the solar wind. The result is more auroral activity on earth. Solar wind is stronger with more sunspot activity, which peaks about every 11 years.

Aurora borealis are best viewed on the northern horizon on a clear night. Colors are stratified and depend on altitude, composition and density of the atmosphere because different gasses emit different colors of light when charged with energy (a principal also used with neon lights). Aurorae are typically greenish-white due to the characteristics of oxygen in earth’s atmosphere. At higher altitudes, oxygen changes and emits a red light more easily captured on film than seen with the naked eye. The bottom edge, about 100 km altitude, may be purple from a mix of red and blue emissions from nitrogen molecules.

Scientists can predict aurora activity, but not with very high accuracy. In fact, predictions are not even as good as weather forecasts. Solar wind takes a couple of days to reach earth’s atmosphere so scientists make predictions based on the sun’s behavior, but this is difficult to do in a global sense let alone for one location.

Get your daily (and hourly) aurora forecast from the University of Alaska’s Geophysical Institute http://www.gi.alaska.edu/AuroraForecast and to see what’s up in space check spaceweather.com.—Marcy Davis

Comments (0) Feb 23 2012

Illume (Photos by Peter Wasilewski)

Peter Wasilewski  retired from NASA’s Goddard Space Filght Center  in April, 2010, but he’s not resting on his laurels. Instead, he’s having a great time with his hobby – Frizion.  Pronounced fri-szhun, from the combination of frozen and vision, Wasilewski’s photographs explore the visual beauty of ice crystal formation.

“I always thought that nature, and in particular ice, has a particular fascination,” Wasilewski says. “Water and ice polymorphs are so fascinating! There are more of them than any other compound in nature – so many ice forms throughout the universe. Mars has a different surface  pressure and temperature structure so the Martian ice would be different from Earth ice. There are many other ice forms. In space, some are amorphous forms of ice.”

A planetary scientist and six-time visitor to the Antarctic, Wasilewski studied the magnetic properties of lunar rocks and meteorites. His first look at ice through the microscope came while collecting meteorites from the Allan Hills in Antarctica. This remote area in the Transantarctic Mountains acts  to collect unusually high concentrations of meteorites that have fallen into high-altitude ice fields and were subsequently transported downhill, trapped in glacial ice in a basin at the foot of the hills. From the dense, blue ice at Allan Hills, Wasilewski created his first thin section, a sliver of ice mounted on a glass slide. The method is generally used for identifying minerals in rocks. Wasilewski was curious to apply the method to ice just as glaciologists do when examining ice cores.

Morning Dragon

“Old ice, like the ice found in the glaciers near Allan Hills, is not very ‘beautiful’ under a microscope. To identify minerals, we use polarized light, which plays with light waves,” Wasilewski explains. “Minerals, including ice, show characteristic properties under polarized light, but with old ice, the crystals are too large and bulky and only clear or white light passes through. It’s with the smaller ice crystals that things get interesting.”

Wasilewski’s curiosity piqued during the 1980 Olympics in Lake Placid, New York, where he made thin sections of ice cores taken from the rink where the hockey and figure skating competitions were held. He noticed that special care was taken to ensure that particular properties of ice were taken into consideration when preparing for each event and, consequently, the ice could be used to reveal the recipe used to create the ice surface – a kind of quality assurance.

In 2001, Wasilewski founded NASA’s History of Winter program, a professional development course for upper middle school and high school science teachers. Each February, 25 teachers spend one week living at Northwood School in Lake Placid learning to use the tools and methodologies for the study of  snow and ice. Participants spend most of their time outdoors learning the science behind ice climbing, digging snow pits for snow stratigraphy exercises, drilling lake ice cores, and making thin sections of the ice.

“My approach is to provide content and hands-on experience. We don’t teach [the teachers] how to teach but we teach them how science is done using snow and ice,” says Wasilewski. “The science they do on site provides the basis for ground truth for NASA satellites and other weather observation data and also gives them the tools to be better science teachers. For each teacher we have at our camp, perhaps they influence 1000 students.”

Taos

It was during the 2001 History of Winter that Wasilewski ‘s Frozen  Vision began to take shape. While looking at a thin section of ice core from Cascade Lake, he noticed a spiral pattern frozen into the ice, probably related to the spiral distribution of  methane bubbles escaping from the bottom of the lake and freezing in the ice.

Since then, Wasilewski’s kitchen has become his Frizion lab. He experiments with temperature gradients and photographs the water using polarized light as it freezes. Over time, he’s learned to crudely manipulate freezing water into several categories of shapes. Variations in ice thickness create different colors.

“Like snowflakes, no two [Frizions] are the same,” Wasilewski explains. “If I had ultrapure, unagitated water I could get to -40°F before it would freeze instantly, but I cannot get there with my freezer. I’ve stayed up all night in my kitchen taking pictures because once you get into it, you can’t stop.”

Wasilewski has big plans for Frizion’s future. He currently has exhibitions at several galleries across the country including Peabody Essex Museum’s Ripple Effect, The Art of H2O,  in Salem, Massechusetts,  an extended special exhibition on water, and he has several  prints up at the Franklin Institute Science Museum in Philadelphia.

Wasilewski will continue  his involvement with the History of Winter and included his Frizions in CryoConn, a program for Alaska educators to learn about snow science spawned by the History of Winter.

Peter Wasilewski (right) with John Cogswell outside the Cogswell Gallery in Vail, Colorado. Photo: Peter Wasilewski

Over the last couple of years, Wasilewski has been experimenting with installation pieces like at the Cogswell Gallery in Vail in January, 2010, where he printed a Frizion image on clear plastic and froze it into a block of ice that became the lead into the rest of the display. Through Facebook, he’s establishing friendships with performance ice sculptors in hopes of  understanding the necessary place for Frizions in trendy ice bars and other spectacular ice displays all over the world. Wasilewski plans to experiment with his technique as well by photographing ice crystals as they begin to melt from a solid and will take photographs through large blocks of ice. He also plans to develop short stories to accompany ice-related non-Frizion art.

You can see more of Peter Wasilewski’s work at the Frizion website, the Polar Artist Group website, and on Facebook. For more information or to order Frizion prints, contact Wasilewski directly at magnetman22@gmail.com. –Marcy Davis

Comments (0) Feb 19 2012

Summit Station Turnover Update

Big House, Summit Station, Greenland

We are very pleased to write that a second Twin Otter flight, delayed for several days due to weather, flew to Summit Station today, picked up its passengers, and departed for Iceland. The Phase III staff is now home alone for the next two months. No slapstick violence though, okay guys?

Comments (0) Feb 16 2012

High winds drift snow along the back of a large building, the Science and Operations Barn, at Summit Station, Greenland. Photo: Luke Nordby

For the second consecutive day, flight operations have been cancelled for Summit Station today due to local high winds and reduced visibility. While the Twin Otter continues to wait in Kangerlussuaq, CPS Summit operations and science project managers, Tracy Sheeley and Katrine Gorham respectively, will linger with the Phase III team for another day. Since the team that tended the research station from November through early February flew out over the weekend, the pair is content to drift like the snow. Waiting for weather is existential, a beat in the rhythm of polar work, and they each have plenty they can do from Summit.

Comments (0) Feb 14 2012

One down, one to go

A quick stop on the roof of the world to drop off the last bit of science cargo, pick up the outgoing Summit staff and refuel the Twin Otter, and the Norlandair crew headed to Kangerlussuaq. Photo: Katrine Gorham

The first of two ‘take out’ flights departed Summit Station for Kangerlussuaq on Saturday, carrying the five-person, November-to-February winter crew with it. A second flight scheduled for today was canceled due to weather in Kangerlussuaq. “There is a big front moving in from the south, and the pilots are concerned about icing conditions,” wrote Tracy Sheeley, CPS operations manager for the station. As a result of the cancellation, Tracy and Katrine Gorham, our science projects manager, remain at Summit, the NSF-funded research station with our new five-person staff.

We’re delighted that our winter crew got out on time, and will keep you posted on the take-out. Stay tuned!–Kip Rithner

If you're happy and you know it, pose for a picture! Many thanks to our Phase II Summit winter crew, which is off to warmer climes and lower latitides. Photo: Katrine Gorham

Comments (0) Feb 12 2012