September 20, 2009, 17:00 PDT

Busy bees

Feeling the sting of climate change

Of all the millions of insect species in the world, the honey bee is arguably one of the most charismatic. These creatures are best known for producing prodigious amounts of honey, the sweet amber substance they create by digesting and regurgitating sugar-rich nectar found within the petals of flowering plants. Then there's the dancing: they perform a range of complex "waggle" dances to communicate. But they also happen to be the workhorse of our agricultural system, pollinating crops ranging from almonds to watermelons to peaches. In the U.S., for example, they contribute more than $14 billion to agriculture each year.

Now — thanks to an innovative project conceived by Wayne Esaias, a NASA oceanographer and keen beekeeper — bees have yet another role: that of climate data collectors.

When honey bees search for nectar, colony scouts tend to scour far and wide and sample the area around a hive remarkably evenly, regardless of the size of the hive. And that means they excel at keeping tabs on flowering ecosystems in ways that even a small army of scientists could not.

The key information that bees collect relates to the nectar flow, which in the mid-Atlantic region tends to come in a burst in the spring. Major nectar flows, typically caused by blooms of tulip-poplar and black locust trees, leave an unmistakable fingerprint on beehives — a rapid increase in hive weight sometimes exceeding 20 lbs per day. When a nectar flow finishes, the opposite is true: hives start to lose weight, sometimes by as much as 1 lb a day.

Esaias, who works at NASA's Goddard Space Flight Center in Maryland, has been studying this cycle of beehive yo yo dieting in the U.S., as he explains in the video above. By combining hive weight changes with space satellite data that reveal vegetation change on the ground, along with other data that go back to the 1920s, he has found that the timing of spring nectar flows has undergone extraordinary change. "Each year, the nectar flow comes about a half-day earlier on average," says Esaias. "In total, since the 1970s, it has moved forward by about month in Maryland." In an interesting demonstration of citizen science, Esaias has set up a network of amateur beekeepers — HoneyBeeNet — who use industrial-sized scales to weigh their hives each day. While the majority of sites are in Maryland, HoneyBeeNet now has sites in more than 20 states. With a little help from people, a birds eye view from space, and a lot of help from honeybees, we might be able to get a handle on just how climate change is affecting our ecosystems.

Oh, and if you're interested in a slightly different take on the honeybee dance, check out the video below.

Adapted from an article by Adam Voiland, NASA Earth Science News Team.

September 17, 2009, 17:00 PDT

Pick of the pics

Louisiana silt

Pick of the pics

This striking image is the result of silt, which appears blue as the Mississippi River flows off the southern coast of Louisiana and into the Gulf of Mexico. The brightness and shade of blue depends on the density of the silt and the depth of the silt-carrying currents in the water. The small bright dots in the scene are fishing boats and oil platforms. The picture was taken by NASA's Landsat 7 satellite on December 28, 2002.

September 9, 2009, 17:00 PDT

Silver lining

Breakthrough in cloud watching

Heads in the clouds: Dr. Raymond Dickie (left) and Professor Robert Cahill (right) with their new cloud-watching device. Courtesy of Queen's University Media Services.
Heads in the clouds: Dr. Raymond Dickie (left) and Professor Robert Cahill (right) with their new cloud-watching device. Courtesy of Queen's University Media Services.

Those white fluffy objects you see in the sky are not as innocuous as they might seem. Clouds exert an enormous influence on our weather and climate. For starters, they carry water — and lots of it — around the world, driving the Earth’s water cycle. Second, they help to balance the Earth’s "energy budget” — by either reflecting the sun’s energy back out into space (low clouds) or acting as a “blanket” that traps heat in the atmosphere (high clouds).

The 64 million dollar question is this: Just how big an effect can clouds have on the climate? Even small changes in the amount of clouds in the sky could alter the climate as dramatically as anticipated increases in greenhouse gases have been predicted to do. There are also complicated “cloud-climate feedbacks” to contend with: changes in climate that are caused by clouds can, in turn, give rise to further changes in clouds, and so on and so forth. It’s enough to give scientists, who are trying to predict future climate change by developing state-of-the-art climate models (akin to weather forecasts), a serious headache.

Engineers in northern Ireland have now come to the rescue. Professor Robert Cahill and colleagues at Queen’s University Belfast have designed a high-performance electronic gadget, known as a “Frequency Selective Surface (FSS) filter”, which can detect heat radiation in the sky up to a very high frequency — regardless of how those heat waves are polarized. Polarization is an important characteristic of many types of waves (light, radio, heat waves, for example) and describes the orientation of the wave oscillations as the waves travel along. Up until now, spaceborne instruments have only been able to pick up heat waves of one particular polarization at a time from gases in the Earth’s atmosphere. The new FSS filter will pave the way towards more complicated cloud imaging that has until now been impossible. Plans are already afoot to integrate the technology into next-generation atmospheric probes that will be launched by the European Space Agency (ESA) next decade.

September 8, 2009, 17:00 PDT

No such thing as fireproof

'A question of when we would burn, not if'

NASA researcher William Patzert studies our climate and our oceans. And has a penchant for loud shirts!
NASA researcher William Patzert studies our climate and our oceans. And has a penchant for loud shirts!

“The history of California is written in great fires.” So says Dr. William Patzert, a climatologist and oceanographer based at NASA’s Jet Propulstion Laboratory (JPL) in Pasadena, Calif. Patzert is one of thousands of southern Californian residents who have been affected by the wildfires that erupted in the Angeles National Forest two weeks ago.

In an article in the Pasadena Star-News, Patzert argues that southern California was actually very lucky, as driving winds could have made the fire much, much worse. Here’s an excerpt:

"I'm stressed out and exhausted. My Sierra Madre neighborhood has been blanketed by ash and smoke. We've closed up everything and set the air conditioner at 80 degrees, but the smoke smells have seeped in and my sleep has been restless. My nerves and I'm sure many others, are on edge. But, driving into JPL one morning last week, I took a deep breath ... cough, cough ... and realized how much worse all this could have been. Yep, I might not be driving into JPL, if Santa Ana winds had propelled this mammoth fire out of the Angeles National Forest and into the crowded foothill neighborhoods. Wind-driven and out of control, this immense fire would have been a full-blown disaster."

Click here to read the full story.

September 2, 2009, 17:00 PDT

Under fire

Turning a corner in battle against L.A. inferno

Feeling the heat. Last week, the fires raged in the foothills around NASA's Jet Propulsion Lab (JPL). Courtesy of Brent Buffington, JPL.

Feeling the heat. Last week, the fires raged in the foothills around NASA's Jet Propulsion Lab (JPL). Courtesy of Brent Buffington, JPL. Hi-res image

One of the largest blazes in southern California’s history is now 38 percent contained, according to the latest reports, but we will have to wait for another couple of weeks until the fire is completely contained.

The "Station Fire" broke out on August 26, 2009, in La Cañada Flintridge, Calif., just a few miles from NASA’s Jet Propulsion Laboratory (JPL). It was started by a combination of factors: Triple-digit temperatures, extremely low humidity, dense vegetation that has not burned for several decades, and years of extended drought. As of this morning, the blaze had burned 145,000 acres (227 square miles) of the Angeles National Forest, destroyed 64 houses, forced tens of thousands of people to evacuate their homes, and caused the deaths of two firemen who were involved in a crash whilst trying to escape rapidly advancing flames. Photos of the inferno are available here (taken by NASA's TERRA space satellite) and here (from locals on the ground).

On Monday, JPL, which is located in La Cañada Flintridge, was shut down because of the proximity of the fire and air quality concerns, but was back up and running a day later. Nearby, the flames began to inch up Mount Wilson, home to the famous Mount Wilson Observatory and numerous communications and broadcasting towers. Los Angeles County Fire Inspector Edward Osorio told reporters from the Los Angeles Times that firefighters are "pretty confident [that] Mount Wilson is going to be OK," following a concerted effort to set backfires and drop thousands of gallons of fire retardant on the mountaintop.

The causes of wildfires are multi-faceted. But scientists are beginning to think that there is a firm link between fires and climate change. According to a 2006 paper published in Science, wildfire activity in the western U.S. has increased markedly since the mid-1980s, with more frequent large fires and longer fire seasons. "The greatest increases [in wildfire activity] occurred in mid-elevation, northern Rockies forests, where land-use histories have relatively little effect on fire risks," wrote the researchers. They ultimately concluded that more frequent wildfires "are strongly associated with increased spring and summer temperatures and an earlier spring snowmelt" — all changes that have been linked to global warming.