Green Tech

Arctic sea ice is not only shrinking in coverage area; it's also thinning, according to a report and satellite images jointly released on Monday by NASA and the NASA-supported National Snow and Ice Data Center at the University of Colorado.

The Arctic basin is covered in a thick semipermanent sea ice, which is covered in thin seasonal ice caps that are built up each winter, only to melt away again each summer.

The 2009 Arctic summer-melting season is starting out with a substantial amount of thin seasonal ice and an unusually small amount of the thick sea ice, making it more vulnerable to melting, according to the NSIDC's report.

"Thin seasonal ice--ice that melts and refreezes every year--makes up about 70 percent of the Arctic sea ice in wintertime, up from 40 (percent) to 50 percent in the 1980s and 1990s. Thicker ice, which survives two or more years, now comprises just 10 percent of wintertime ice cover, down from 30 (percent) to 40 percent," according to the report from the University of Colorado team led by Charles Fowler.

At left, median image of sea ice thickness at the end of each February cycle. On right, the sea ice thickness for 2009.

(Credit: Chuck Fowler and Jim Maslanik, University of Colorado/NSIDC)

The findings should not be entirely surprising to those who have been following NASA and the NSIDC's research. In September 2008, the groups issued a joint report that the Arctic's thick permanent ice was at one of the lowest levels on record, in terms of coverage area.

A team led by Ron Kwok of NASA's Jet Propulsion Laboratory is further examining sea ice data to determine if there's a correlation between the reduction in sea ice coverage area and the changes in thickness and volume.

"Sea ice thickness has been hard to measure directly, so scientists have typically used estimates of ice age to approximate its thickness. But last year, a team of researchers led by Ron Kwok of NASA's Jet Propulsion Laboratory in Pasadena, Calif., produced the first map of sea ice thickness over the entire Arctic basin," according to NASA's report.

Kwok's team is using data from NASA's IceSat (Ice, cloud, and land elevation satellite) to measure Arctic sea ice thickness and volume for 2003 to 2008, to see if there's is a correlation between sea ice coverage area and volume.

So far, the team has reached the same conclusion as Fowler's group.

"The older, thicker sea ice is declining and is being replaced with newer, thinner ice that is more vulnerable to summer melt," Kwok said in a statement.

"With these new data on both the area and thickness of Arctic sea ice, we will be able to better understand the sensitivity and vulnerability of the ice cover to changes in climate," he said.

Images chronicling the change in sea ice coverage area in the Arctic from NASA's QuikScat satellite taken each January 1 since 1999. NASA noticed a 40 percent decrease between 2005 and 2007. Now Kwok's team is looking at thickness and volume.

(Credit: Ron Kwok, NASA/JPL)

NASA has issued a preliminary report confirming environmentalists' fears of disappearing sea ice at the Arctic.

Sea ice is the thick permanent ice formed by frozen ocean water that remains even as seasonal ice melts away in the summer. In the past, it has covered about 60 percent of the Arctic.

The sea ice at the Arctic has now been found to have melted away by as much as half, according to a preliminary report issued Tuesday by NASA and the NASA-supported National Snow and Ice Data Center at the University of Colorado.

"According to NASA-processed satellite microwave data, this perennial ice used to cover 50 to 60 percent of the Arctic, but this winter it covered less than 30 percent," NASA said in a statement.

It is the second-smallest amount of coverage since NASA began monitoring the situation in 1979. The Artic's sea ice coverage this September is about 33 percent below average, compared with the record low of 39 percent below average recorded in 2007.

At this time, neither NASA nor the National Snow and Ice Data Center have made suggestions as to the possible cause for the change. A thorough analysis of the data is scheduled to be released the first week of October, according to NASA.

NASA image showing ice levels (in white) for September 12, 2008, at the Arctic. The orange line indicates the average amount of ice coverage for that day between 1979 and 2000. The black cross is the geographic North Pole.

(Credit: National Snow and Ice Data Center)

Team Lambada, a UFM-13 Lambada, a motor glider sport plane, won $33,000 in NASA's challenge for quietest plane.

(Credit: Stefanie Olsen/CNET News)

SONOMA COUNTY, Calif.--When it comes to flying, being green isn't easy.

Here at NASA's second annual General Aviation Challenge this weekend, one of the main prizes was the so-called "green prize," which challenged two-seater planes to fly a 400-mile-long course logging at least 30 miles to the gallon. None of the four planes entered won the $50,000 prize; the best attempt achieved 28.8 miles per gallon. (NASA's ultimate goal is to get the green prize to at least 100 miles per hour and the equivalent of 100 miles per gallon.

The shoe-in to win the green prize--a team with a novel "omnivore" biodiesel engine capable of flying on french fry oil--pulled out of the race at the last minute because of a mechanical problem.

"Ironically, our biggest advance this year was with a plane that didn't fly," said Andy Petro, head of NASA's Centennial Challenges, a series of government-sponsored competitions that support space exploration and aviation technologies in private industry. Petro was referring to the team Kantankeros Katana's dual biodiesel and gas engine, which could conceivably run on everything from automobile gasoline to kerosene. Contest organizers have said that a biodiesel-engine plane could go 900 miles on 25 gallons.

Despite this year's letdown, NASA plans to retool its contest next year to focus primarily on fuel-efficient aviation, according to Petro.

"Next year, we'll be emphasizing fuel efficiency as the ultimate goal with planes that maintain the characteristics of practical aircraft," he said. The prize money will be up to $400,000 at next year's event.

The Cafe Foundation, a nonprofit group of flight test engineers, hosted the aviation challenge here at the Charles M. Schulz Sonoma County Airport in California. The races ended Saturday and the winners were announced Sunday.

Apart from the green prize, NASA awarded about $100,000 of its total $300,000 allotted for the second annual challenge, less money than what was doled out last year. One of the biggest prizes it granted was $50,000 for aircraft safety to the lone returning competitor, the Slovenian-built Pipistrel known as Virus. The plane, which was the big winner at the 2007 event, had added such precautions as a cabin integrated with Kevlar and an installed ballistic parachute system, or a deployable rocket that would launch a parachute 100 feet above the plane in the event of an emergency.

NASA also awarded prizes for competitors' ability to fly quietly--a characteristic that's of increased importance as planes land nearer to communities. The Pipistrel, for example, used a carbon-fiber propeller on its aircraft this year to reduce its noise by at least 10 percent, but that shift cut the plane's fuel-efficiency by as much as 50 percent. The "Prius of airplanes," the 100-horsepower-engine Pipistrel typically can go as fast as 170 mph and get 50 miles to the gallon.

The Slovenian-built Pipistrel won prizes in NASA's aviation challenge for safety, shortest take-off, and quietest cabin.

(Credit: Stefanie Olsen/CNET News)

Overall, NASA has staked a total of $2 million for the five annual aviation contests. (Last year, NASA awarded $250,000 in prize money.) In 2005, the challenges were originally devised as a way to advance so-called personal air vehicles, or PAVs, so that in the future, people could beat gridlock by commuting in a two-seater plane with zero emissions. NASA backed away from that Jetsons-like view of the future this year by changing the contest to promote general aviation technologies, such as the development of tech for unmanned aircraft.

One of the keys to a vision of PAVs is energy efficiency. The CAFE Foundation has said that it expects to see its first electric airplane competitor by 2009--and at least one of the contestants is on track to deliver on that expectation.

Pipistrel plans to begin selling the first commercially produced, two-passenger electric aircraft, the Taurus Electro by the end of the year. On one charge, the Taurus glider is expected to travel as much as 1,000 miles in a day. It will cost $133,000. (Pipistrel's Virus costs about $110,000.)

Geoff Stevenson, a mechanical engineer and owner of the biodiesel plane, a modified Diamond DA20-A1, said that he and his brother had to pull their craft from the contest because its air inlet temperature sensor was broken. It wasn't communicating with the on-board computer. They also had yet to test fly the plane. Still, he thought it would have been competitive in the green prize and they plan to race next year.

"The push to develop a diesel engine is worthy because of the limited availability of aviation leaded fuels," Stevenson said. He added that he and his brother spent about $15,000 on the 12 year old air frame, and another $3,500 to develop the engine.

One of the more encouraging signs of this year's race, Petro said, was that engineers from the Slovenian sport-plane company Pipistrel showed up and modified their craft to specifications of the challenge. For example, they added insulation to the cabin to cut down on noise and installed an electronic engine and flight management system to improve the plane's safety. The flight management system, which draws on GPS and satellite systems, would act as a guide to the pilot in the event of bad weather.

Part of the goal of the aviation challenge is to get the aircraft industry thinking about innovations in fuel-efficiency, safety, and noise reductions.

"We don't expect revolutionary advances at this stage. But we are making incremental steps in that direction," Petro said.

NASA's Jet Propulsion Laboratory released images on Wednesday depicting offshore wind energy potential around the world.

Gathered from almost 10 years of satellite data, the wind maps can be used by offshore wind energy developers to measure which sites have the best resource.

Red and white colors indicate high wind energy is available while blue color reflects lower energy.

(Credit: NASA Jet Propulsion Laboratory.)

The best sites, depicted in red, have a steady and high wind speed for most of the year. Offshore wind turbines have the advantage of not having wind blocked by buildings or land formations.

Wind energy could supply 10 percent to 15 percent of the world's electricity needs, said Paul Dimotakis, chief technologist at NASA's Jet Propulsion Laboratory.

Dimotakis said offshore wind turbines could produce electricity cheaper than solar energy could.

There are no offshore wind farms in the United States, but many expect that it's a matter of time before one will be built. New types of turbines are being developed so that they can be anchored farther offshore.

The Cape Wind project, though highly criticized, is moving forward in its approval process. And a project led by Bluewater Wind off the coast of Delaware was recently approved by the state legislature.

Earlier this week, oil prospector T. Boone Pickens announced the Pickens Plan, which set the goal of getting 20 percent of U.S. electricity in 10 years from land-based wind turbines in the middle of the country

Satellites flying in this formation can analyze the chemicals in and behaviors of clouds close to Earth.

(Credit: NASA)

New methods of using satellites to examine clouds are helping scientists to understand how pollution influences rainfall.

Researchers from the National Aeronautics and Space Administration have used a group of satellites known as the Afternoon Constellation, or A-Train, to peer into the chemical composition and behaviors of clouds.

"Typically, it is very hard to get a sense of how important the effect of pollution on clouds is," Anne Douglass, deputy project scientist for NASA's Aura satellite, said in a statement. "With the A-Train, we can see the clouds every day and we're getting confirmation on a global scale that we have an issue here."

Until recently, scientists generally have paid less attention to clouds than to views of Earth, which the clouds can block.

Five satellites orbiting 8 minutes apart were able to make almost simultaneous observations. Each satellite played a different role, such as looking at carbon monoxide levels, rainfall patterns, or the size of particles of ice in clouds.

The presence of carbon monoxide in clouds indicates aerosols and smoke coming from land-bound pollution sources including power plants and forest fires.

Polluted South American clouds made less rain than cleaner clouds, according to work by scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Ice was found to be smaller in clouds laced with aerosol, preventing rainfall during the parched season between June and October.

However, for reasons that remain unclear, rainy seasons in South America and South Asia appeared to be less influenced by aerosol levels in clouds.

The five satellites used are Aqua, Aura, CloudSat and CALIPSO from NASA, and France's PARASOL.

Findings were presented at the Joint Assembly of the American Geophysical Union in Fort Lauderdale, Fla.

This image shows the alternating periods of stronger and weaker rainfall, called a Madden-Julian Oscillation. Blue and red represent high and low rainfall across the equatorial region of the Earth. The 1987-1988 season had particularly pronounced MJO activity, and MJOs are strongest in the Indian Ocean region.

(Credit: NASA)

SAN FRANCISCO--Scientists are trying to peer a bit further into the future than the typical five-day weather forecasts available today.

Forecasting weather is a notoriously tough challenge that combines physics modeling, data collection, and computer processing--and unlike many scientific problems, pretty much everyone on the planet cares how well it's done. But forecasts today peter out after a few days, leaving a cloud of uncertainty (forgive me) that only lifts when it comes to predicting seasonal weather phenomena such as El Nino.

Scientists are now getting a handle on intermediate-term forecasts by computer models of a particular type of large-scale weather phenomenon called a Madden-Julian Oscillation discovered in the early 1970s. These MJOs are linked to phenomena including Atlantic hurricane seasons and South Asian monsoons, and modeling them with a computer can "provide new predictions with lead times of one to three weeks," said Duane Waliser, principal scientist for water and carbon cycles at NASA's Jet Propulsion Laboratory, speaking today at the American Geophysical Union conference here.

When MJOs occur, rainfall alternates between periods of greater and lesser intensity, typically with each period lasting 40 to 50 days and the pattern gradually traveling east across the planet, Waliser said. Although they take place at equatorial latitudes, their effects extend farther north and south into the middle latitudes, Waliser said.

Only recently have MJO computer models become very good at predicting the actual phenomena, he said.

"Five to ten years ago, you would have been hard-pressed to find any models that represented it that well at all," Waliser said. Now, though, multiple institutions are working on the problem, and scientists actually have a choice of models.

One problem with using MJOs to predict medium-term weather, though, is that they are only intermittent phenomena that take place roughly two to six times per year. "If it's there, we have something to go on. If it's not, then we don't."