Tropically Speaking, NASA Investigates Precipitation Shapes, Sizes for Severity

Rain drops are fat and snowflakes are fluffy, but why does it matter in terms of predicting severe storms?

We've all seen fat rain drops, skinny rain drops, round hailstones, fluffy snowflakes and even ice needles. This summer, NASA researchers are going to get a look at just how much these shapes influence severe storm weather. To do it, they'll have to look inside the guts of some of the world's fiercest storms. NASA recently assembled a team of hurricane scientists from across the country to carry out high-altitude-aircraft surveillance to explore in detail how storms form, intensify and dissipate.

Earth scientists and engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., have redesigned one of their instruments, the Advanced Microwave Precipitation Radiometer, or AMPR, to better observe the different shapes of precipitation. In August and September, AMPR will fly at an altitude of 60,000 feet over the Gulf of Mexico and Atlantic Ocean. It will sit in the bomb bay of a WB-57 airplane, which is based at the NASA Johnson Space Center's Ellington Field in Houston.

AMPR will sit in the bomb bay of a WB-57 airplane, where it will scan the surfaces below to measure both how hard it’s raining and the type of precipitation being produced by a storm. (NASA/JSC)

During these flights, AMPR researchers will test a new build -- the instrument is an upgraded version of the original AMPR built at NASA Marshall in the early 1990s -- and use it to participate in NASA's upcoming hurricane study, the Genesis and Rapid Intensification Processes field campaign, better known as GRIP. The campaign involves three planes mounted with 14 different instruments, including AMPR. The instruments will all work together to create the most complete view of a hurricane to date.

Researchers hope the hurricane campaign will help them answer some of nature's most perplexing questions. As tropical storms grow, they produce massive amounts of rain -- a key element in the development of full-scale hurricanes. Scientists will use AMPR along with the other instruments, such as data from the Tropical Rainfall Measuring Mission or TRMM satellite, to figure out just how hard it's raining inside these ferocious storms, and how much of that rain is associated with the production of ice during intensification.

"If you don't know how hard it's raining or where the rain is forming in the atmosphere, you don't know hurricanes," said Dr. Walt Petersen, AMPR principle investigator and Marshall Center earth scientist. "AMPR provides us an opportunity to see their precipitation structure by using an instrument like those currently flying on, for example, the TRMM and Aqua satellites in space."

That's because AMPR doesn't just give scientists new information about hurricanes. The instrument also enables them to test equipment currently in space. Every day, numerous weather satellites orbit Earth to measure the rainfall rate of storms across the globe. They work much like AMPR except over much larger scales. Because they're so far above the Earth and moving so fast, they can take only one measurement every few miles along their track. Scientists can correct for such coarse measurements, but to do so they need highly accurate data. AMPR can take several measurements per mile, giving scientists the data they need to verify that weather satellites continue to provide accurate data.

Crashing waves in the deep ocean can generate enough energy to create a seismic "hum." (Bruce Molnia/U.S. Geological Survey)

"It's like the pixels in your computer screen," Petersen said. "When satellites take measurements, they have really big pixels, and we might lose some of the finer details of what's happening on the ground. AMPR has much smaller pixels, much higher resolution, and allows us to see a much clearer picture. It's a part of our arsenal to make sure what we're measuring from space makes sense. We'd hate to send something up and not have it accurately measure what's happening on the ground."

That information translates into better predictions of hurricane track and intensity -- how hard it's going to rain in a certain area when a hurricane hits, for example, aiding in early flood warnings.

AMPR doesn't just measure how hard rain falls. Within the last several years, the AMPR team has worked vigorously to upgrade the instrument. These upgrades will enable AMPR to more accurately detect what kind of precipitation is in the storm. By identifying the shape of the precipitation, AMPR may present scientists with recognizable signatures that define different types of precipitation. For example, varying combinations of fat or skinny rain drops, snow, ice or hail distributed throughout the depth of the storm will produce different brightness temperatures when viewed at different angles. A storm may develop and behave differently depending on these variations.

Engineers packed the 380-pound AMPR payload with a delicate set of instruments and computer hardware. AMPR gathers data by measuring the amount of microwave radiation rising from the surface beneath -- often the ocean. Because rain water is a better emitter of microwave radiation than ocean water, the radiation measured from rainfall is actually greater during a big storm. This measurement is converted to a "brightness temperature," which correlates to how much radiation is being generated. The more rain, the higher the brightness temperature.

Alternatively, if a hurricane's clouds are full of ice or hail, as they usually are, much of the microwave radiation is scattered away. The corresponding brightness temperature is much lower than the anticipated surface measurement. Scientists can use those changes to determine how hard it's raining inside a storm or how much ice a given storm might contain.

"Whether rain drops are fat or skinny, and whether ice is round or bumpy, these factors are critical when we're trying to estimate rainfall rates," Petersen explained. "Because of air drag, the rate at which these precipitation particles fall through the air depends on their thickness or shape. A fat rain drop falls more slowly than a hail stone of the same size, for example -- that factor enables you to determine rainfall rate."

This image over Southern Brazil, taken from the space shuttle by an astronaut in February 1984 and shows a mixture of cold and warm clouds. (NASA/JSC)

After the GRIP experiment ends in September, Petersen and his team will unload the data and begin analyzing it, adding their findings to the increasingly large body of hurricane knowledge.

"The GRIP experiment will give us information about how a hurricane circulates and how it intensifies. Basically we have a bunch of theories about the role of precipitation in hurricanes, and we need to test them. That's where instruments like AMPR come in."

After this summer’s hurricane study, AMPR will continue to fly in storm campaigns. It's already scheduled for a major joint NASA and U.S. Department of Energy study in April 2011 to support the Global Precipitation Measurement

Petersen loves the challenge. Storms have fascinated him ever since his junior year of high school, when lightning struck just inches away from him while he was at a drive-in movie.

"The thing that excites me is looking inside a storm that we can't fly into," he said. "We can't fly inside these big storms because they're just too nasty. The only way to get information about what's going on inside is to do what AMPR does.

"Being able to look at the guts of a storm and figure out what's going on, that's the key thing for me," he added.

With any luck, AMPR's look into hurricanes will put scientists one step closer to predicting some of the world's fiercest storms.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/news/ampr.html

GRIP 'Shakedown' Flight Planned over Gulf Coast

The first flight of NASA's hurricane airborne research mission is scheduled to take off from Ft. Lauderdale, Fla., on Tuesday, Aug. 17. NASA's DC-8 research aircraft will be making a planned five-hour flight along the Gulf Coast from western Florida to Louisiana primarily as a practice run for the many scientific instruments aboard.

Mission scientists, instrument teams, flight crew and support personnel gathered in Fort Lauderdale this weekend to begin planning the six-week Genesis and Rapid Intensification Processes mission, or GRIP. NASA's DC-8, the largest of NASA's three aircraft taking part in the mission, is based at the Fort Lauderdale airport. The two other aircraft -- the WB-57 based in Houston and the autonomous Global Hawk flying out of southern California -- will join the campaign in about a week.

The NASA DC-8 airplane on the tarmac at the Fort Lauderdale International Airport in Florida on Aug. 15 as preparations continue for its part in the GRIP hurricane experiment. Credit: NASA/Paul E. Alers

The target for Tuesday's "shakedown" flight is the remnants of Tropical Depression 5, a poorly organized storm system whose center is currently hugging the coasts of Mississippi and Louisiana and moving westward. While forecasters do not expect this storm system to strengthen significantly before it reaches landfall in Louisiana, the system offers the DC-8's seven instrument teams an opportunity to try out their equipment on possible convective storms. Rainfall rates, wind speed and direction below the airplane to the surface, cloud droplet sizes, and aerosol particle sizes are just some of the information that these instruments will collect.

Jeffrey Beyon (left) and Paul Joseph Petzar of NASA's Langley Research Center work on the Doppler Aerosol Wind Lidar (DAWN) instrument aboard NASA's DC-8 research aircraft on Aug. 15. Credit: NASA/Paul E. Alers

GRIP science team members and project managers are now meeting daily at the airport to review weather forecasts and plan upcoming flights with their counterparts in two other airborne hurricane research missions sponsored by the National Atmospheric and Oceanic Administration (NOAA) and the National Science Foundation. Instrument teams are also working on their equipment onboard the DC-8 in preparation for the flight.

The GRIP science team met on Aug. 16 in Fort Lauderdale to review weather forecasts and plan the first flight of NASA's DC-8 aircraft. Credit: NASA/Paul E. Alers

On Sunday, Aug. 15, NASA's Global Hawk completed a successful test flight over NASA's Dryden Flight Research Center in Edwards, Calif., that took the remotely piloted plane to an altitude of 60,000 feet. The last of three instruments being mounted on the Global Hawk for GRIP is being installed this week.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/news/shakedown-flight.html

M-Class Solar Flare Erupts

An M-class flare erupted in active sunspot region 1093, peaking at 1824 UTC on August 7, 2010. The eruption hurled a coronal mass ejection (CME) into space. NASA's Solar Dynamics Observatory observed the flare. The CME is not fully directed toward Earth, but some of the plasma cloud may glance the magnetosphere between August 9 and August 10, causing a geomagnetic disturbance and possible aurora.

Credit: NASA/SDO

Scientists classify solar flares according to their x-ray brightness in the wavelength range 1 to 8 Angstroms. There are 3 categories: X-class flares are major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. M-class flares are medium-sized; they can cause brief radio blackouts that affect Earth's polar regions. Minor radiation storms sometimes follow M-class flares. Compared to X- and M-class, C-class flares are small with few noticeable consequences on Earth.

For more information visit http://www.nasa.gov/topics/solarsystem/sunearthsystem/main/News080910-flare.html

NASA Lightning Research Happens in a Flash

Lightning's connection to hurricane intensification has eluded researchers for decades, and for a riveting 40 days this summer, NASA lightning researchers will peer inside storms in a way they never have before.

Earth scientists and engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., will soon fly the Lightning Instrument Package, or LIP, a flight instrument designed to track and document lightning as hurricanes develop and intensify. In August and September, LIP will fly on a remotely piloted Global Hawk airplane over the Gulf of Mexico and Atlantic Ocean at an altitude of 60,000 feet. LIP will be part of a NASA hurricane study called Genesis and Rapid Intensification Processes, or GRIP for short. The study involves three storm chaser planes mounted with 15 instruments. LIP and the other instruments will work together to create the most complete view of hurricanes to date.

Dr. Richard Blakeslee (right) and Tony Kim (left) of the Marshall Center test the electric field mills used to measure lightning produced by thunderstorms. (NASA/MSFC/D. Stoffer)

"We're now putting LIP on an aircraft that can stay in the air for 30 hours," said Richard Blakeslee LIP principal investigator and Earth scientist at the the Marshall Center. "That’s unprecedented. We typically fly on airplanes that fly over a storm for a period of 10-15 minutes. But this plane can stay with a storm for hours."

"We'll be able to see a storm in a way we’ve never seen it before," he added. "We'll see how the storm develops over the long term, and how lightning varies with all the other things going on inside a hurricane. It's the difference between a single photograph and a full-length movie. That’s quite a paradigm shift."

While scientists know an increase in lightning means the storm is changing, it remains a mystery as to whether that increase signifies strengthening or weakening. Though scientists have quite a few ideas, they lack the data to firmly establish a concrete relationship. Researchers hope LIP's upcoming flights will change that. If scientists can figure out the ties between lightning and hurricane severity, meteorologists may be able to greatly improve their short-term forecasts. Researchers have connected lightning to everything from strong winds to flooding to tornadoes, and a few extra minutes of warning time can save lives each year.

The Lightning Instrument Package will fly aboard the Global Hawk, a remotely piloted airplane that reaches altitudes of 60,000 feet, about twice the height of a commercial airliner. LIP has flown numerous times before, but will now be on an aircraft that can stay in the air for 30 hours, an unprecedented improvement. (NASA)

"We can use lightning as a natural sensing tool to see into the heart of a storm," said Blakeslee. "Lightning allows us to get at rain and other processes going on within a storm."

For Blakeslee and the rest of the LIP team, the hurricane study this fall presents a tremendous opportunity. In its nearly 15-year lifespan, LIP has flown nearly 100 missions in 10 major field campaigns, soaring over more than 800 storms. That's unparalleled for a lightning instrument, according to Blakeslee, and LIP researchers hope it will continue its long tradition of successful research.

The Guts of the Lightning Instrument Package

LIP's instruments may look simple, but they're surprisingly complex. To measure the electric field in a storm, the instrument relies on electric field mills, devices that allow scientists to measure the amount of lightning a storm produces. Originally developed at NASA, the mills look like big cans -- each about a foot long and approximately 8 inches across. As the instrument flies through the air, a plate covering each can rotates, covering and uncovering four metal disks housed inside. Uncover a disk and electricity from the storm rushes in. Cover the disk and it rushes back out. The whole process converts the electrical current from DC to AC and back to DC, allowing scientists to measure how strong a storm's electric field is, and how prone to lightning it might be. A sudden shift in the strength of the electrical field allows scientists to determine that a lightning strike has occurred.

In addition, a conductivity probe reveals how easily electrical current can flow through the storm to the upper part of the atmosphere. The probe is a small nose-cone shaped device with two sensor tubes attached to each side. As the plane flies near a hurricane, small electrical particles called ions rush through the tube, allowing the team to count them.

The instrument will measure the amount of lightning produced by hurricanes and tropical storms. Lightning’s connection to hurricane intensification has eluded researchers for decades, and NASA scientists hope the upcoming hurricane experiment will help answer some puzzling questions. (NASA)

The LIP team uses all that data to determine how much lightning a hurricane produces and where it originates within the storm. By combining that data with wind speed, rainfall rate and other information, researchers can connect how lightning relates to hurricane intensification. And because Blakeslee and his team get their data real time, they can redirect the plane as needed to improve the likelihood of quality results.

After the summer hurricane study ends in September, the team will analyze, evaluate, and eventually release the data, a process which should take several months. Following that, the Lightning Instrument Package will continue to fly in hurricane and storm studies in hopes of collecting more data. The more data, the better the forecasts, Blakeslee said -- and the nearer scientists move to understanding these powerful storms.
The Long Journey of LIP

Of course, Blakeslee and the rest of the LIP team have had to overcome their fair share of challenges.

"When we first started out, we didn’t even know if what we do now was possible," Blakeslee said. "One of my colleagues told me, 'You won’t be able to make current measurements over storms.' But I said, 'Yes we can.' And now we do."

Lightning can serve as a natural sensing tool that allows scientists to understand what else could be happening in a storm. (National Weather Service/F. Smith)

"It's a pretty rewarding feeling," he said. "The biggest challenge now is that there’s always more to study than we possibly can. We've got to pick and choose, and sometimes that can be frustrating."

But for Blakeslee, there's nothing else he'd rather do.

"Lightning is just cool," he laughed. "I've always enjoyed hands-on science, and everything about lightning measurements is hands-on science. You build the instruments. You put them on airplanes. You go out and fly them. You get back the data. And then there's the satisfaction that it’s not all abstract -- we can actually apply what we're learning to real people, real situations and real problem-solving."

For now, the LIP team looks forward with anticipation to sending their instrument out on an unprecedented journey -- hopefully one that will bring scientists one step closer to solving one of science’s biggest mysteries.

For more information about NASA storm research and upcoming study, visit:

http://www.nasa.gov/grip

For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/news/lightning.html

NASA's TRMM Satellite Sees Heavy Rainfall in Hurricane Alex

Hurricane Alex is generating some very heavy rainfall, and the Tropical Rainfall Measuring Mission satellite known as TRMM has been calculating it from its orbit in space.

As predicted by the National Hurricane Center (NHC) in Miami, Florida, Alex intensified after entering the warm waters of the southwest Gulf of Mexico.

At NASA's Goddard Space Flight Center in Greenbelt, Md., scientists created an analysis of Alex's rainfall using data captured by the TRMM satellite on June 29, 2010 at 1350 UTC (9:50 a.m. EDT). At that time the sustained winds around Alex were estimated to be 60 knots (~69 mph). Alex continued to strengthen and was classified as a hurricane early on 30 June 2010. This made Alex the first hurricane in the 2010 Atlantic hurricane season.

The rainfall analysis used TRMM Precipitation Radar (PR) data and TRMM Microwave Imager (TMI) data. The TMI data showed that a heavy band of precipitation (some areas showed rain falling at more than 2 inches per hour) was spiraling into the center of Alex's intensifying circulation. The precipitation analysis was overlaid on visible and infrared data from TRMM's Visible Infrared Scanner (VIRS). In this image a Geostationary Operational Environmental Satellite (GOES East) visible image was used to fill in locations not viewed by the TRMM satellite.

The TRMM satellite's data on June 29, 2010 at 9:50 a.m. EDT showed some heavy rain (red) falling at up to 2 inches per hour, spiraling toward Hurricane Alex's center. The yellow and green areas indicate moderate rainfall between .78 to 1.57 inches per hour. Credit: NASA, Hal Pierce

Alex is expected to continue to be a large rainmaker when it makes landfall. Rainfall accumulations are expected of between 6 and 12 inches, with isolated amounts of 20 inches.

Tropical Storm-force winds are expected to reach coastal areas in the warning areas this afternoon, while hurricane-force winds will reach the coast tonight. In addition, the National Hurricane Center noted "a dangerous storm surge will raise water levels by as much as 3 to 5 feet above ground level along the immediate coast to the north of where the center makes landfall."

By 11 a.m. EDT, Alex was still a category one hurricane with maximum sustained winds near 80 mph. Alex was located about 145 miles (235 km) east of La Pesca, Mexico and 190 miles (310 km) southeast of Brownsville, Texas. That makes Alex's center near 23.8 North and 95.5 West. Alex is moving northwest at 7 mph (11 km/hr), and has a minimum central pressure near 961 millibars.

Satellite data show that Alex is a large hurricane and the hurricane force winds extend outward up to 60 miles (95 km) from the center. Tropical storm force winds extend outward up to 200 miles (325 km) primarily to the northeast of the center.

The National Hurricane Center noted today that "Given such a low minimum pressure...the current satellite presentation and a favorable environment for intensification...the winds should increase today and Alex could reach category two before landfall."

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_alex.html

Tropical Cyclone Phet Intensifies, Coastal Oman Bracing for Strong Winds, Heavy Rains

Tropical storm Phet intensified over the last 24 hours and has grown into a full-blown and powerful cyclone. NASA's Terra satellite imagery of the storm from earlier today also revealed an eye in the storm, confirming the intensification. Residents of coastal Oman are bracing for strong winds, heavy rainfall and rough surf today and tomorrow.

NASA's Terra satellite flew over Tropical Cyclone Phet at 06:55 UTC (2:55 a.m. EDT or 6:55 p.m. local time/Pakistan). The Moderate Resolution Imaging Spectroradiometer instrument, or MODIS captured a visible image of Phet at that time, and noticed an eye in the center of the storm's circulation. Satellite imagery indicates the eye is about 12 kilometers (7 miles) in diameter.

NASA's MODIS instrument captured a visible image of Phet at 06:55 UTC (2:55 a.m. EDT or 6:55 p.m. local time/Pakistan) on June 2, and indicated the eye is about 12 kilometers (7 miles) in diameter. Credit: NASA Goddard/ MODIS Rapid Response Team

At 0900 UTC (9 p.m. local time/Pakistan), Tropical Cyclone Phet had maximum sustained winds near 110 knots (126 mph) with gusts to 135 knots (155 mph). It is now considered a major cyclone (equivalent to a Category 3 hurricane on the Saffir-Simpson hurricane scale). It is about 560 miles southwest of Karachi, Pakistan, near 17.7 North and 60.6 East. It is moving to the northwest near 5 knots (6 mph). Cyclone-force winds extend to 35 miles from the storm's center, while tropical-storm force winds extend as far as 75 miles from the center. It is creating very rough seas on the Arabian Sea with waves as high as 18 feet.

Cyclone Phet is a threat to coastal Oman, India (Gujarat), and Pakistan (Sindh and Balochistan). The Joint Typhoon Warning Center (JTWC) has forecast the storm to continue intensifying and to approach Oman on its way to a weekend landfall in southeastern Pakistan between Karachi and to the border with India.

RSMC New Delhi warns that gale force winds will be experienced along the Oman coast today and tomorrow as Phet continues to move through the Arabian Sea.

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_phet.html

Hurricane Season 2010: Tropical Storm Phet (Northern Indian Ocean)

Tropical Cyclone Phet Threatens the Indian and Pakistani Coastlines

NASA satellite imagery confirmed that Tropical cyclone 03A has intensified quickly in the last 24 hours, and as a result, the storm has been renamed Tropical Storm Phet. Phet is located in the Arabian Sea, Northern Indian Ocean, and is threatening the Indian and Pakistani coastlines.

NASA's Aqua satellite flew over Tropical Storm Phet on June 1 at 9:11 UTC (5:11 EDT) and captured an infrared image of the cloud top temperatures. The image indicated large areas of high, cold cloud tops, as cold as -63 degrees Fahrenheit, indicating strong convection.

At 1500 UTC (11 a.m. EDT) on June 1, Tropical Storm Phet had maximum sustained winds near 55 knots (62 mph) with higher gusts. Phet was located about 550 miles south-southwest of Karachi, Pakistan, near 16.8 North and 62.2 East. Phet is moving to the northwest near 6 knots (7 mph).

NASA's Aqua satellite flew over Tropical Storm Phet on June 1 at 9:11 UTC (5:11 EDT) and captured this infrared image of the cloud top temperatures. The purple color indicates high, cold cloud tops, as cold as -63 degrees Fahrenheit, indicating strong convection. Credit: NASA JPL, Ed Olsen

Current landmasses threatened by Phet include: India (Gujarat), Pakistan (Sindh and Balochistan).

Phet is forecast to continue strengthening and turn northeast later this week. The Joint Typhoon Warning Center forecasts landfall by the end of the week in the border area between India and Pakistan.

Regional warnings are already in effect for the Indian and Pakistani coastlines from Thursday on. The Indian Meteorological Department's Regional Specialized Meteorological Center noted on June 1, "Under the influence of this system, fairly widespread rainfall with isolated heavy to very heavy falls would commence over coastal areas of Gujarat from June 3 and increase thereafter. Squally winds with speed reaching 55-65 kmph (34-40 mph) (with higher gusts) would commence along and off Gujarat coast from June 2 and increase gradually." For updated forecasts, visit: www.imd.gov.in

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_phet.html

Sailor Reflects on NASA Technology That Saved His Life

Just seven days after setting sail for a tiny island off the eastern tip of Puerto Rico on Dec. 26, 2009, Missourian Dennis Clements thought his life was over; his crippled 34-foot Fiberglas sailboat -- buffeted for four days by gale-force winds and high seas -- had capsized, tossing him into the frigid waters of the North Atlantic Ocean.

A storm capsized Dennis Clements's boat off the coast of Cape Hatteras, N.C., in January. Clements owes his rescue to the crew of the U.S.S. Dwight D. Eisenhower, as well as to NASA satellites and a 406 MHz beacon. Video credit: NASA's Goddard Space Flight Center

"At one point, I saw the mast pointed straight down to the bottom of sea, and the boat continued to roll," he said. "I was shaken loose somewhere underwater and when I reached the surface, I could see my boat about 30 feet away... I could see her stand up... She righted herself. She was heavily flooded. There was still a piece of sail and I saw it catch the wind. I saw her sail away and leave me there. And I was alone in the dark, and in the storm, 250 miles from the shore... As I floated there, I knew this was the end. This was how it would end for me."

Today, Clements considers himself fortunate.

Thanks to NASA technology, the Search and Rescue Satellite-Aided Tracking (SARSAT) program managed by the National Oceanic and Atmospheric Administration (NOAA), and the bravery of military rescuers, Clements was ultimately plucked to safety by a Navy seaman who had been dispatched from the U.S.S. Dwight D. Eisenhower. It was the only vessel within a hundred miles of Clements' location able to respond to the Coast Guard's call for help and attempt the rescue, which took only four minutes once the Navy helicopter arrived on the scene. "It was the bravest thing I've ever seen," Clements said.

A Coast Guard rescue swimmer from Air Station Atlantic City prepares to enter the water off of Atlantic City, N.J., during a water rescue training exercise Sept. 28, 2006.Credit: U.S. Coast Guard photo by PAC Tom Sperduto

In a sense, Clements dramatic rescue began years earlier when he bought a 406 MHz Emergency Position Indicating Radio Beacon (EPIRB), designed for maritime use. When his sailboat, "Gloria Adios" had taken on water, the beacon activated, transmitting an emergency distress signal that NOAA weather satellites equipped with NASA-developed repeaters then relayed back to NOAA-operated ground stations. While Clements battled the storm, which was slowly but surely overwhelming his sailboat, a chain reaction had already been set in place before the rogue wave had even capsized his boat.

Sometime after the beacon began transmitting the emergency alert, SARSAT equipment located hundreds of miles away received the signal and had begun processing it to determine its precise location. The U.S. Coast Guard, which is responsible for at-sea rescues, received the alert and searched the NOAA Registration Database to determine whether the beacon had been registered. Luckily for Clements, he had done so, providing emergency contact numbers and other information that the Coast Guard used to contact Clements' family.

The database is a vital part of the SARSAT program. "We use the database to provide critical information to help expedite the search process, especially if the location of the beacon is not immediately known," said Mickey Fitzmaurice, a space systems engineer for the SARSAT program, the organization that operates the U.S. component of the COSPAS-SARSAT system now comprised of 40 nations.

The beacon on Clements' boat was an older model and did not encode GPS location data, with its signal. However, the ground-station equipment used the Doppler effect from its low-Earth-orbiting weather satellites to help pinpoint the location of the signal. This can take a little time depending on where the satellites are located at the time of the incident. While the SARSAT system calculated the location of the signal, a Coast Guard search and rescue controller was on the phone calling to find out if Clements had gone to sea and where he was headed. From this information, a more precise location could be provided to the rescuers.

A variety of emergency beacons used to transmit distress signals. All 406 MHz beacons can and should be registered, and Search and Rescue authorities encourage owners of these beacons to do so as registration will help rescue forces find persons in distress faster in an emergency. http://www.beaconregistration.noaa.gov/ Credit: NASA/Goddard/Rebecca Roth

Given the harrowing weather conditions the night Clements was rescued, Fitzmaurice said it fortuitous that Clements had registered his beacon. The U.S. Coast Guard was able to confirm the validity of Clements’s distress signal. Therefore, the U.S. Coast Guard and U.S. Navy personnel involved in his rescue were not unnecessarily exposed to life-threatening conditions due to a false alert.

"The beacon registration information can help save lives, not only the person in distress, but also the rescuers," said LCDR Kathy Niles, U.S. Coast Guard SARSAT Liaison Officer. "NOAA's database currently contains about 275,000 registrations which, unfortunately, are only about 75 percent of the beacons out there."

Since his rescue on Jan. 2, 2010, Clements has had time to reflect on the technology and people who saved his life. "I'm very glad I had that beacon," he said. "I knew it was a satellite system and somewhere there were people monitoring it, but I didn't know it was a weather satellite. It really is a wonderful system that they have come up with," he said. "It speaks volumes about the United States of America in the things that matter to us as a nation, that we would invest time, resources, and manpower (into technologies) that save people's lives."

Now, NOAA, NASA, the U.S. Coast Guard, and U.S. Air Force officials say they are working together to develop and new and improved search and rescue system, called the Distress Alerting Satellite System (DASS).

Engineers at the NASA Goddard Space Flight Center in Greenbelt, Md., are developing next-generation search and rescue technologies that will more quickly detect and locate distress signals generated by 406 MHz beacons installed on aircraft and vessels or carried by individuals. That's because NASA plans to install the repeaters on Global Position System (GPS), a constellation of 24 spacecraft operating in mid-Earth orbit, and not weather satellites.

"A few years ago, we looked to see how we could improve the system and we concluded that the international search and rescue community would benefit from new technology installed on GPS," said NASA Search and Rescue Mission Manager David Affens. "We would be able to identify distress signals faster and with a greater level of precision. In the end, this will save more lives, reduce risk to rescuers, and save money because less time will be spent searching."

Inside the Search and Rescue Mission Office at NASA's Goddard Space Flight Center in Greenbelt, Md. Credit: NASA/Goddard/Debbie McCallum

The improved response time is made possible because of the coverage provided by a constellation of satellites encircling the globe. With a mid-Earth orbit search and rescue capability provided by GPS, one emergency signal goes off, and at least four satellites will be in view. Almost instantly, processing of the signal can begin to determine its precise location."

Although the current system is effective, as evidenced by Clements' rescue and those of 27,000 others worldwide since the system became operational in the mid-1980s, a satellite may not be in position to pick up a distress signal the moment a user activates the beacon. Furthermore, weather satellites in geostationary orbit cannot independently locate a beacon unless it contains a navigation receiver that encodes and transmits its position -- a capability not offered on most units. "Right now, it can take an hour or more before we can even act on a signal," Fitzmaurice said.

The new GPS-based system is now being tested. Currently, nine GPS satellites are flying the proof-of-concept technology and an additional 12 are planned. Goddard is conducting testing to fine tune the technology before transitioning to a final system after 2015, which will be deployed on the Air Force’s Block III GPS satellites.

"The bottom-line here is that within one minute, we'll know where the distress signals come from," Fitzmaurice said. "It is the future."

For more information visit http://www.nasa.gov/topics/technology/features/search-rescue2010.html

Copernicus

800 million years ago an impactor struck the eastern extent of Oceanus Procellarum, the "Ocean of Storms." The bright-rayed crater Copernicus was formed: the crater now considered representative of many lunar craters created during the Copernican period on the Moon.

Copernicus crater is 93 km wide. LOLA data reveals that its crater rims reach almost 300 m above the lunar mean elevation level, while its floor rests near -1700 m. The blue areas contained within the interior purple of the impact crater in this LOLA image reveal Copernicus’s three central peaks.

Image credit: NASA/Goddard

Spacing between tracks of LRO orbits is larger near the equator than the poles. This spacing leads to greater interpolation of equatorial data and lowers the resolution of LOLA images, including this image of Copernicus, created in this region of the Moon.

Related Links:

› LOLA instrument Web site

For more information visit http://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lola-20100430-copernicus.html

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NASA's New Eye on the Sun Delivers Stunning First Images

NASA's recently launched Solar Dynamics Observatory, or SDO, is returning early images that confirm an unprecedented new capability for scientists to better understand our sun’s dynamic processes. These solar activities affect everything on Earth.

Some of the images from the spacecraft show never-before-seen detail of material streaming outward and away from sunspots. Others show extreme close-ups of activity on the sun’s surface. The spacecraft also has made the first high-resolution measurements of solar flares in a broad range of extreme ultraviolet wavelengths.

"These initial images show a dynamic sun that I had never seen in more than 40 years of solar research,” said Richard Fisher, director of the Heliophysics Division at NASA Headquarters in Washington. "SDO will change our understanding of the sun and its processes, which affect our lives and society. This mission will have a huge impact on science, similar to the impact of the Hubble Space Telescope on modern astrophysics.”

A full-disk multiwavelength extreme ultraviolet image of the sun taken by SDO on March 30, 2010. False colors trace different gas temperatures. Reds are relatively cool (about 60,000 Kelvin, or 107,540 F); blues and greens are hotter (greater than 1 million Kelvin, or 1,799,540 F). Credit: NASA

Launched on Feb. 11, 2010, SDO is the most advanced spacecraft ever designed to study the sun. During its five-year mission, it will examine the sun's magnetic field and also provide a better understanding of the role the sun plays in Earth's atmospheric chemistry and climate. Since launch, engineers have been conducting testing and verification of the spacecraft’s components. Now fully operational, SDO will provide images with clarity 10 times better than high-definition television and will return more comprehensive science data faster than any other solar observing spacecraft.

A movie of the March 30, 2010, solar prominence eruption, as seen by SDO. Credit: NASA/Goddard

SDO will determine how the sun's magnetic field is generated, structured and converted into violent solar events such as turbulent solar wind, solar flares and coronal mass ejections. These immense clouds of material, when directed toward Earth, can cause large magnetic storms in our planet’s magnetosphere and upper atmosphere.

SDO will provide critical data that will improve the ability to predict these space weather events. NASA's Goddard Space Flight Center in Greenbelt, Md., built, operates and manages the SDO spacecraft for the agency’s Science Mission Directorate in Washington.

“I’m so proud of our brilliant work force at Goddard, which is rewriting science textbooks once again.” said Sen. Barbara Mikulski, D-Md., chairwoman of the Commerce, Justice and Science Appropriations Subcommittee that funds NASA. “This time Goddard is shedding new light on our closest star, the sun, discovering new information about powerful solar flares that affect us here on Earth by damaging communication satellites and temporarily knocking out power grids. Better data means more accurate solar storm warnings.”

This image compares the relative size of SDO's imagery to that of other missions. Credit: NASA

Space weather has been recognized as a cause of technological problems since the invention of the telegraph in the 19th century. These events produce disturbances in electromagnetic fields on Earth that can induce extreme currents in wires, disrupting power lines and causing widespread blackouts. These solar storms can interfere with communications between ground controllers, satellites and airplane pilots flying near Earth's poles. Radio noise from the storm also can disrupt cell phone service.

More "Hello, SDO!" videos from NASA Goddard's Scientific Visualization Studio. Credit: NASA/Goddard/Chris Smith

SDO will send 1.5 terabytes of data back to Earth each day, which is equivalent to a daily download of half a million songs onto an MP3 player. The observatory carries three state-of the-art instruments for conducting solar research.

The Helioseismic and Magnetic Imager maps solar magnetic fields and looks beneath the sun’s opaque surface. The experiment will decipher the physics of the sun’s activity, taking pictures in several very narrow bands of visible light. Scientists will be able to make ultrasound images of the sun and study active regions in a way similar to watching sand shift in a desert dune. The instrument’s principal investigator is Phil Scherrer of Stanford University. HMI was built by a collaboration of Stanford University and the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, Calif.

The Atmospheric Imaging Assembly is a group of four telescopes designed to photograph the sun’s surface and atmosphere. The instrument covers 10 different wavelength bands, or colors, selected to reveal key aspects of solar activity. These types of images will show details never seen before by scientists. The principal investigator is Alan Title of the Lockheed Martin Solar and Astrophysics Laboratory, which built the instrument.

The Extreme Ultraviolet Variability Experiment measures fluctuations in the sun’s radiant emissions. These emissions have a direct and powerful effect on Earth’s upper atmosphere -- heating it, puffing it up, and breaking apart atoms and molecules. Researchers don't know how fast the sun can vary at many of these wavelengths, so they expect to make discoveries about flare events. The principal investigator is Tom Woods of the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. LASP built the instrument.

"These amazing images, which show our dynamic sun in a new level of detail, are only the beginning of SDO's contribution to our understanding of the sun," said SDO Project Scientist Dean Pesnell of Goddard.

SDO is the first mission of NASA's Living with a Star Program, or LWS, and the crown jewel in a fleet of NASA missions that study our sun and space environment. The goal of LWS is to develop the scientific understanding necessary to address those aspects of the connected sun-Earth system that directly affect our lives and society.

For more information visit http://www.nasa.gov/mission_pages/sdo/news/first-light.html

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See Spot on Jupiter. See Spot Glow.

New thermal images from powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot, enabling scientists to make the first detailed interior weather map of the giant storm system.

The observations reveal that the reddest color of the Great Red Spot corresponds to a warm core within the otherwise cold storm system, and images show dark lanes at the edge of the storm where gases are descending into the deeper regions of the planet. These types of data, detailed in a paper appearing in the journal Icarus, give scientists a sense of the circulation patterns within the solar system's best-known storm system.

"This is our first detailed look inside the biggest storm of the solar system," said Glenn Orton, a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., who was one of the authors of the paper. "We once thought the Great Red Spot was a plain old oval without much structure, but these new results show that it is, in fact, extremely complicated."

New thermal images from powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot. Image credit: NASA/JPL/ESO and NASA/ESA/GSFC

Sky gazers have been observing the Great Red Spot in one form or another for hundreds of years, with continuous observations of its current shape dating back to the 19th century. The spot, which is a cold region averaging about 110 Kelvin (minus 260 degrees Fahrenheit) is so wide about three Earths could fit inside its boundaries.

The thermal images obtained by giant 8-meter (26-foot) telescopes used for this study -- the European Southern Observatory's Very Large Telescope in Chile, the Gemini Observatory telescope in Chile and the National Astronomical Observatory of Japan's Subaru telescope in Hawaii -- have provided an unprecedented level of resolution and extended the coverage provided by NASA's Galileo spacecraft in the late 1990s. Together with observations of the deep cloud structure by the 3-meter (10-foot) NASA Infrared Telescope Facility in Hawaii, the level of thermal detail observed from these giant observatories is comparable to visible-light images from NASA's Hubble Space Telescope for the first time.

One of the most intriguing findings shows the most intense orange-red central part of the spot is about 3 to 4 Kelvin (5 to 7 degrees Fahrenheit) warmer than the environment around it, said Leigh Fletcher, the lead author of the paper, who completed much of the research as a postdoctoral fellow at JPL and is currently a fellow at the University of Oxford in England. This temperature differential might not seem like a lot, but it is enough to allow the storm circulation, usually counter-clockwise, to shift to a weak clockwise circulation in the very middle of the storm. Not only that, but on other parts of Jupiter, the temperature change is enough to alter wind velocities and affect cloud patterns in the belts and zones.

"This is the first time we can say that there's an intimate link between environmental conditions -- temperature, winds, pressure and composition - and the actual color of the Great Red Spot," Fletcher said. "Although we can speculate, we still don't know for sure which chemicals or processes are causing that deep red color, but we do know now that it is related to changes in the environmental conditions right in the heart of the storm."

Unlocking the secrets of Jupiter's giant storm systems will be one of the targets for infrared spacecraft observations from future missions including NASA's Juno mission.

For more information visit http://www.nasa.gov/topics/solarsystem/features/jupiter20100316.html

90Q: A Curious Short-Lived "Tropical" Cyclone in the Southern Atlantic

Tropical cyclones typically don't form in the Southern Atlantic because the waters are usually too cool. However, forecasters at the Naval Research Laboratory noted that a low pressure system off the coast of Brazil appeared to have tropical storm-force winds yesterday.

On Wednesday, March 10 at 1400 UTC (9:00 a.m. ET) "System 90Q" was located near 29.8 degrees South latitude and 48.2 degrees West longitude, about 180 miles east of Puerto Alegre, Brazil. The Naval Research Laboratory said on March 10 the system had maximum sustained winds near 39 mph (35 knots) but has weakened today below the tropical storm-force winds threshold.

The GOES-12 satellite captured this visible image of System 90Q at 14:45 UTC (9:45 a.m. ET) on March 10, 2010. 90Q is the small circular area of clouds (lower left center). Credit: NASA GOES Project

The Geostationary Operational Environmental Satellite, GOES-12 captured a visible image of System 90Q at 14:45 UTC (9:45 a.m. ET) on March 11, and it appeared as a small circular area of clouds off the Brazilian coast. GOES is operated by the National Oceanic and Atmospheric Administration, and NASA's GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md. creates some of the GOES satellite images.

System 90Q continues to move away from the Brazilian coast and is expected to be absorbed in a mid-latitude cold front in the next couple of days.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_90Q.html

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Hurricane Season 2010: Tropical Storm 17P (Southern Pacific)

Seventeenth South Pacific Tropical Cyclone Forms

On February 21, the seventeenth tropical depression formed in the South Pacific Ocean. Today, February 22, the storm has strengthened into Tropical Storm 17P (TS 17P) with maximum sustained winds near 39 mph, and it was about 740 miles east-northeast of Pago Pago.

The Geostationary Operational Environmental Satellite, GOES-11 captured a visible image of the storm at 1800 UTC (1 p.m. ET) February 22. The storm does not appear well organized. TD 17P was located near 9.6 South latitude and 159.0 East longitude, and was moving south-southwest near 4 mph (3 knots). TS 17P was creating 15 foot-high waves in open waters.

GOES-11 captured a visible image of the Tropical Storm 17P at 1800 UTC (1 p.m. ET) February 22. Credit: NOAA/JTWC

Although TS 17P is expected to continue tracking in open waters its winds and surf may impact some land areas. So, regional warnings have been posted for the Northern Cook Islands. Currently, a gale wind warning is in effect for Penrhyn and an alert is in effect for Rakahanga, Manihiki and nearby islands.

TS 17P is in an area of wind shear, and that's limiting any intensification of the storm. It is expected to strengthen a little more over the next couple of days however, before it dissipates later this week.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2010/h2010_17P.html

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Riding out the Snow Storm Inside Goddard to Carry on the Mission

Hundreds of ground crew workers at NASA Goddard Space Flight Center in Greenbelt, Md. have been working since Friday afternoon to keep buildings safe and ensure essential employees are there to support the Space Shuttle Endeavour (STS-130) mission and the launch and operation of the Solar Dynamics Observatory (SDO). Crews continue to work very hard to make sure the Center is ready to return to normal operations once this storm is over.

Civil servants, contractors, and subcontractors are working together using hundreds of front loaders, Bobcats®, snow plows, dump trucks, and shovels to clear roads and sidewalks on Center.

The biggest challenge to handling this storm is finding a place to put all the snow, according to Eric Holmes, Goddard Facility Manager. “We hauled over 2,000 thousand truckloads of snow and dumped it behind Building 28,” said Holmes. “We’ve built ‘Mount Goddard’.”

Emergency planning began last Wednesday, February 3, when Holmes received a weather report from AccuWeather about the storm. “We made sure we had enough fuel, rock salt, and magnesium chloride,” said Holmes. “About 250 tons of rock salt was delivered to the Center on Thursday. We also made sure contractors and Government personal were prepared.”

Goddard Space Flight Center gates. Credit: NASA/Eric Holmes, Goddard Facility Manager.

Crews will live inside Building 4 for the duration of the storm. There is a full kitchen and hundreds of cots and air mattresses set up.

We were prepared to open the Center this week," says Holmes. "However, because of the surrounding county roads, Center management thought it would be safer for employees to stay home."

Space Shuttle and Solar Dynamics Observatory Mission Support

“Employees have staffed the Network Integration Center (NIC) 24 hours a day since last Friday,” says Jim Bangerter, Network Director for Human Space Flight at Goddard Space Flight Center.

Crews piles tons of snow behind building 28. Credit: NASA/Eric Holmes, Goddard Facility Manager.

Goddard provides critical communications for human spaceflight missions. The Goddard team provides data to Johnson Space Center’s Mission Control Center that allows them to monitor the performance of thousands of systems on the Shuttle, send flight commands and navigational instructions, relay science data, support voice communications between the astronauts and mission control along with video and live television feeds.

In addition to the Shuttle, Goddard also provides critical mission support to the Solar Dynamics Observatory through its entire mission from Building 14’s Mission Operation Center. The Center is fully staffed and ready to monitor and control the spacecraft through its initial orbits, using the orbital data provided to them by the Flight Dynamics Facility (FDF).

Building 28 parking on Saturday. Credit: NASA/Joan Dunham, Flight Dynamics Support Services (FDSS) Operations Domain Lead, a.i. solutions.

Pre-storm planning for Shuttle and SDO mission support began early last week. Contractors secured rooms at the Greenbelt Holiday Inn and Greenbelt Marriott hotels. They also made sure they had 4-wheel-drive vehicles. Employees packed extra food, water, and shovels. “Several people who did not have to work over the weekend volunteered to drive people between the hotels and Goddard during the storm,” said Melissa Blizzard, Human Space Flight Operations Center Manager. Blizzard works in the NIC. “I was amazed by how people pulled together to help one another during this storm.”

“We could not say enough about the work the ground crew is doing at Goddard,” said Joan Dunham, Flight Dynamics Support Services Operations Domain Lead with a.i. solutions, a contractor at the FDF. “Crews spent a lot of time clearing snow from parking lots and sidewalks from behind Building 28. It’s like plowing an ocean,” said Dunham, “They cleared one area and more snow fills in.”

Dunham adds that on Friday night, February 5, about a dozen dump trucks, bulldozers, and Bobcats® worked to clear the Building’s parking lot. They also kept a backup generator clear of snow. Building 28 houses the Flight Dynamics Facility and NASA Television operations. Both facilities are critical to mission operations.

Bangerterscar.jpg Jim Bangerter’s car Monday morning. Credit: NASA

Bangerter stayed in the NIC from Friday afternoon to Monday morning. Bangerter lives in Annapolis, Md. and didn’t want to take a chance on the roads. He slept on a couch in the Mission Management Area. “It was kind of like the old days, before some our operations were moved to White Sands, NM a few years ago,” said Bangerter. “We used to camp out at Goddard during storms like this.”

NASA Goddard contractors did a great job planning for this storm. “Nobody missed a shift,” Bangerter said. “Everyone was able to focus on the Space Shuttle launch. I am deeply grateful for those who put themselves in harm’s way to make sure our crews were able to get to work safely.”

Friday and Saturday night snow removal crews made it possible to access the Building. There were several cars in the parking lot and crews cleared snow around everyone’s cars. Crews helped Bangerter dig his car out of the snow Monday morning.

Flight Dynamics Facility Staff inside building 28. Credit: NASA/Joan Dunham Flight Dynamics Support Services (FDSS) Operations Domain Lead, a.i. solutions.

“The streets and sidewalks inside Goddard are pretty good compared to the streets outside Goddard,” said Melissa Blizzard. “Crews are plowing continuously.”

Many mission support personal were able to take a break after the Space Shuttle launch. Several dozen, however, were right back at Goddard for the Solar Dynamics Observatory launch.

Meanwhile, ground crews continue to clear snow from sidewalks and roads around Goddard. They will be working through the storm until Goddard is able to open again. “We are a very big team here,” said Holmes. “Everyone is goal-oriented here. We recognize we are part of history.”

For more information visit http://www.nasa.gov/centers/goddard/news/features/2010/blizzard.html

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Hurricane Season 2009: Tropical Storm David (Southern Indian Ocean)

Tropical Storm David Forms and Romps in the Southern Indian Ocean

Tropical Storm David formed over the weekend and as a depression, has been romping around the open waters of the Southern Indian Ocean and will continue to do just that. David is located approximately 580 nautical miles west-southwest of Diego Garcia, near 11.3 degrees South and 63.8 degrees East.

AIRS captured a visible image of David on December 21, 4:17 a.m. ET and David didn't appear to be well organized, although the storm is now strengthening. Credit: NASA JPL, Ed Olsen

David has been tracking in a westward direction, but it now changing course and moving east-southeast near 7 mph. David's maximum sustained winds are near 46 mph, and the storm may strengthen over the next couple of days.

Animated infrared satellite imagery, such as that using NASA's Atmospheric Infrared Sounder (AIRS) instrument on the Aqua satellite, indicates slight improvement in organization over the past 12 hours despite moderate northwesterly vertical wind shear. AIRS captured an infrared and visible image of David on December 21 at 09:17 UTC (4:17 a.m. ET) and noticed that David had some high thunderstorm tops indicating strong convection and strong thunderstorms with heavy rainfall. The cloud tops were as cold or colder than minus 63 degrees Fahrenheit!

AIRS captured an infrared image of David on December 21, 4:17 a.m. ET and noticed that David had some high thunderstorm tops (purple) indicating strong convection and strong thunderstorms with heavy rainfall. The cloud tops were as cold or colder than minus 63 degrees Fahrenheit! Credit: NASA JPL, Ed Olsen

On December 21 at 1504 UTC (10:04 ET) the Tropical Rainfall Measuring Mission (TRMM) satellite, a satellite managed by NASA and the Japanese Space Agency, flew over David to analyze the storm's rainfall. The image showed convective banding, that is, bands of thunderstorms, wrapping from the north of the storm into the south of the storm. Microwave imagery, however, such as that from NASA's Aqua satellite showed that David's low-level circulation is partially exposed, opening the storm up to wind shear, which could weaken it.

David is forecast to keep moving east-southeast for the next 72 hours and then turn southwestward while intensifying slightly. David poses no threat to land.

Text credit: Rob Gutro, NASA's Goddard Space Flight Center

For more information visit http://www.nasa.gov/mission_pages/hurricanes/archives/2009/h2009_David.html

NASA Gets Up-Close Look at Far Corner of the Globe

The Arctic remains in the mind a pristine wonderland. The landmasses that jut into the Arctic Circle are covered by tundra and primeval forest; the pole is covered in ice. The whole environment seems detached from human influence entirely. But the scientific record tells a different story.

A months-long airborne campaign in 2008 gave scientists a new look at how everyday human behaviors in Europe, North America and Asia are affecting the Arctic, the most rapidly changing region on Earth and a major regulator of the planet's climate. The data show human fingerprints all over the Arctic in the form of polluted exhaust from factories and smoke from fires often set by human hands. Observations from the ground have long recorded some of this impact, and satellites in low-earth orbit provide a different view, but scientists had not undertaken a detailed, airborne study of this magnitude in years.

The mission provided a new view of how pollution from industrializing Asian countries influences the Arctic. Ground sensors have long detected the regular, low-altitude movement of polluted air masses from Europe to the Arctic. Because of the colder temperatures in the countries of the pollution's origin, the plumes of carbon dioxide, carbon monoxide and other warming-related gases do not rise high in the atmosphere. On the contrary, pollution from warmer regions in Asia has apparently been moving to altitudes too high for ground instruments to observe well. The airborne instruments provided invaluable measurements of the extent of this pollution, said Daniel Jacob, a Harvard University atmospheric scientist and both mission scientist and co-principal investigator for NASA’s Arctic Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission.

The DC-8 flies above Summit, Greenland. The ARCTAS flights collected a trove of seldom-made measurements of the Arctic atmosphere that are shedding light on the processes at work in the most rapidly warming region on Earth. Credit: NASA

"With Asian pollution, there's a relatively warm ocean immediately downwind of a fairly cold continent, so you have interesting storm tracks that lift pollution and transport it at higher altitudes," Jacob said. "It's certainly a much larger influence on Arctic haze than what had been traditionally ascribed."

Now that researchers have had some time to sift through the data collected, Jacob said the value of these observations is coming in to focus. Major airborne campaigns like this are rare, so almost any study of the Arctic atmosphere in coming years will draw on ARCTAS.

"We're getting to the point where results from ARCTAS are getting into climate models. We’re able to test different models of snow albedoes, and we've been able to introduce some corrections," Jacob said. "From the standpoint of the Asian pollution influence, if you want to claim Asia has a certain influence, you better check it against the ARCTAS results."

While factories, power plants and cars on the highway provide a 365-day-a-year source of pollution, the Arctic flights revealed insights into a more cyclical source of emissions: fires in boreal forests and from agricultural burning as far away as Kazakhstan. In concert with NASA, NOAA sponsored spring flights as part of a field study called Aerosols, Radiation and Cloud Processes affecting Arctic Climate (ARCPAC). These flights observed an unusually active spring fire season. Even if the data collected was somewhat anomalous, scientists say it has provided great insight into fire and smoke influence on the Arctic. In addition, there is some evidence that as the Arctic warms and dries out, there is more fuel for these fires.

NASA's DC-8 casts a shadow on Arctic ice during a campaign in 2008 to measure the presence of pollution from mid-latitude continents and smoke and soot from wildfires in the Arctic atmosphere. Credit: NASA

"We expected to see pollution. But it turns out there's a seasonal cycle to fires, and there’s a springtime peak and summertime peak," said Chuck Brock, ARCPAC project scientist. "I don't think we appreciated that these fires in Siberia and in southern Russia could be so dominant and important in the Arctic. So, is 2008 representative or is it an unusual year? But every year there is this peak, and every year this smoke gets carried to the Arctic."

Brock said the wealth of data will be important in studying the link between smoke and cloud formation and the repercussions of this link. For instance, could there be an impact on snowmelt -- through aerosol-related warming -- if the spring fire season inches up by even a week or two?

The campaigns also provided the opportunity to create a sharper picture of several specific emission sources of greenhouse gases that find their way to the Arctic. Scientists focused on emissions from the oil and gas industry in Prudhoe Bay, Alaska and the natural methane emissions from the massive wetlands near Hudson Bay in Canada. These are two examples of the many variables that need to be accurately characterized in order for scientists to understand what is driving Arctic warming.

It is the rarity of these measurements that makes them important to future study of the Arctic climate, said Jim Crawford, a research scientist at NASA's Langley Research Center and the ARCTAS program manager during the campaign. The data gathered will allow scientists to better interpret satellite observations and better simulate how industrial pollution and wildfire smoke affect the Arctic.

"For scientists interested in studying the role of changing atmospheric composition on climate, the ARCTAS data will represent the best and often only detailed information available for this poorly characterized region," Crawford said.

Related Links:
› ARCTAS Mission

Patrick Lynch
NASA's Langley Research Center

For more information visit http://www.nasa.gov/topics/earth/features/arctas-findings.html

Solar Storms and Radiation Exposure on Commercial Flights

Scientists at NASA’s Langley Research Center have completed a first attempt to accurately calculate the level of damaging radiation flight crews and passengers are exposed to on commercial airline flights. The work is an early step toward developing a model to observe radiation exposure for all commercial flights, particularly for pilots and crews who spend their careers airborne and who are at greater risk of developing certain cancers.

The study considered not only everyday radiation emanating from space, but also the additional energy unleashed during a solar storm, which can be profound. NASA scientists say not including geomagnetic effects on solar radiation in modeling radiation exposure could underestimate the dosage by 30 to 300 percent.

Researchers looked at passengers and crew on typical flights from Chicago to Beijing, Chicago to Stockholm and London to New York, during what is known as the Halloween 2003 Storm. These flights were chosen because of their long flight paths near the North Pole, where the Earth’s natural protection from radiation is weakest. Earth’s magnetic field approaches zero above the poles. The Halloween 2003 event was chosen because it was both a large and a complex storm, making it a good test for the model.

The study found that aircrew and passengers during the Chicago to Beijing flight, for example, would have been exposed to about 12 percent of the annual radiation limit recommended by the International Committee on Radiological Protection. But these exposures were greater than on typical flights at lower latitudes, and confirmed the concerns about commercial flights at high latitudes.

"The upshot is that these international flights were right there at that boundary where many of these events can take place, where radiation exposure can be much higher," said Chris Mertens, senior research scientist at NASA’s Langley Research Center, who is leading the research effort. Mertens will present his latest results at the American Geophysical Union fall meeting in San Francisco on Dec. 16.

Solar storms unleash bursts of radiation that can reach crew and passengers on commercial flights at certain altitudes and latitudes. Scientists at NASA’s Langley Research Center are working on a real-time model of radiation exposure risk for air travel that would include data about powerful solar storms. Eventually the system could be used to log radiation exposure over longer periods of time for pilots and flight crews. Credit: NASA

Piecing together the radiation exposure on these typical flights is the first step toward developing a real-time system that researchers hope will become a standard component of commercial airline cockpits. Radiation exposure could one day be taken into account in the same way weather conditions are considered before deciding to fly or deciding what exact route to fly and at what altitude.

Flying above and beyond Earth’s natural protection

The number of international flights that skirt the north pole are increasing. Airlines save massive amounts of fuel on flights such as Chicago-to-Shanghai by simply flying “over the top” – it is a far shorter route than following the latitude lines. But while saving fuel, these flight paths take planes and their passengers to the thinner layers of Earth’s magnetosphere, which shields potentially harmful solar and cosmic radiation.

On a typical day, the Sun is quiet and “background radiation,” the cumulative effect of radiation from cosmic sources reaching Earth, is the only other source. But when the Sun is not quiet, violent storms on the star’s surface eject powerful bursts of radiation to the Earth. It is these events that have never been truly accounted for in studies of how much radiation pilots and airline passengers are exposed to.

Pilots Await Results

While the flights studied appear to have not put passengers in danger of exceeding the safe radiation limit in an individual flight, concerns remain, Mertens said. Many workers whose jobs expose them to consistent radiation sources log that exposure to keep a record over one’s career. People who work on commercial airline flights are technically listed as “radiation workers” by the federal government – a classification that includes nuclear plant workers and X-ray technicians. But unlike some others in that category, flight crews do not quantify the radiation they are exposed to.

Mike Holland, an American Airlines captain and vice chairman for radiation and environmental issues with the Allied Pilots Association, said he is following Mertens’ research with interest. The pilots association has written a formal letter in support of the research. Holland cited studies that show pilots face a four-times greater risk of melanoma than the general population. But because pilots and flight crews do not wear radiation-measuring badges like other radiation workers, the only estimates about their career-long exposure come from models.

Up until now, most of those models only attempted to capture the amount of cosmic background radiation that reaches airliners in flight. Holland said he believes including solar radiation, especially during solar storms, is important. He looks forward to having answers for the pilots who contact him with questions about radiation and cancer risk.

“When I talk to epidemiologists, they have two questions for me: What is your exposure? And what is your health for 20 to 30 years after you retire?” Holland said. The second question he and other pilots can answer, in time. But as of now, they can’t measure their exposure.

“We’re excited that Chris is doing this,” Holland said, “and we hope it can answer the epidemiologists first question, which is, ‘What is your exposure?’”

Related Links:

> NAIRAS at Space Environment Technologies
> Advanced Satellite Aviation Weather Products (ASAP)
> NASA's Applied Sciences Program

Patrick Lynch
NASA's Langley Research Center

For more information visit http://www.nasa.gov/topics/aeronautics/features/airline-radiation.html