Top Stories: June 2013

Friday, June 28, 2013

NASA Decommissions Its Galaxy Hunter Spacecraft

Thursday, June 27, 2013

NASA's Voyager 1 Explores Final Frontier of Our 'Solar Bubble'

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.jpl.nasa.gov

Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov

Steve Cole 202-358-0918
NASA Headquarters, Washington
stephen.e.cole@nasa.gov

News Release: 2013-209 June 27, 2013

NASA's Voyager 1 Explores Final Frontier of Our 'Solar Bubble'

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-209&cid=release_2013-209

PASADENA, Calif. -- Data from Voyager 1, now more than 11 billion miles (18 billion kilometers)
from the sun, suggest the spacecraft is closer to becoming the first human-made object to reach
interstellar space.

Research using Voyager 1 data and published in the journal Science today provides new detail on the
last region the spacecraft will cross before it leaves the heliosphere, or the bubble around our sun, and
enters interstellar space. Three papers describe how Voyager 1's entry into a region called the
magnetic highway resulted in simultaneous observations of the highest rate so far of charged particles
from outside heliosphere and the disappearance of charged particles from inside the heliosphere.

Scientists have seen two of the three signs of interstellar arrival they expected to see: charged
particles disappearing as they zoom out along the solar magnetic field, and cosmic rays from far
outside zooming in. Scientists have not yet seen the third sign, an abrupt change in the direction of
the magnetic field, which would indicate the presence of the interstellar magnetic field.

"This strange, last region before interstellar space is coming into focus, thanks to Voyager 1,
humankind's most distant scout," said Ed Stone, Voyager project scientist at the California Institute of
Technology in Pasadena. "If you looked at the cosmic ray and energetic particle data in isolation, you
might think Voyager had reached interstellar space, but the team feels Voyager 1 has not yet gotten
there because we are still within the domain of the sun's magnetic field."

Scientists do not know exactly how far Voyager 1 has to go to reach interstellar space. They estimate
it could take several more months, or even years, to get there. The heliosphere extends at least 8
billion miles (13 billion kilometers) beyond all the planets in our solar system. It is dominated by the
sun's magnetic field and an ionized wind expanding outward from the sun. Outside the heliosphere,
interstellar space is filled with matter from other stars and the magnetic field present in the nearby
region of the Milky Way.

Voyager 1 and its twin spacecraft, Voyager 2, were launched in 1977. They toured Jupiter, Saturn,
Uranus and Neptune before embarking on their interstellar mission in 1990. They now aim to leave
the heliosphere. Measuring the size of the heliosphere is part of the Voyagers' mission.

The Science papers focus on observations made from May to September 2012 by Voyager 1's cosmic
ray, low-energy charged particle and magnetometer instruments, with some additional charged
particle data obtained through April of this year.

Voyager 2 is about 9 billion miles (15 billion kilometers) from the sun and still inside the heliosphere.
Voyager 1 was about 11 billion miles (18 billion kilometers) from the sun Aug. 25 when it reached
the magnetic highway, also known as the depletion region, and a connection to interstellar space. This
region allows charged particles to travel into and out of the heliosphere along a smooth magnetic field
line, instead of bouncing around in all directions as if trapped on local roads. For the first time in this
region, scientists could detect low-energy cosmic rays that originate from dying stars.

"We saw a dramatic and rapid disappearance of the solar-originating particles. They decreased in
intensity by more than 1,000 times, as if there was a huge vacuum pump at the entrance ramp onto the
magnetic highway," said Stamatios Krimigis, the low-energy charged particle instrument's principal
investigator at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "We have
never witnessed such a decrease before, except when Voyager 1 exited the giant magnetosphere of
Jupiter, some 34 years ago."

Other charged particle behavior observed by Voyager 1 also indicates the spacecraft still is in a
region of transition to the interstellar medium. While crossing into the new region, the charged
particles originating from the heliosphere that decreased most quickly were those shooting straightest
along solar magnetic field lines. Particles moving perpendicular to the magnetic field did not decrease
as quickly. However, cosmic rays moving along the field lines in the magnetic highway region were
somewhat more populous than those moving perpendicular to the field. In interstellar space, the
direction of the moving charged particles is not expected to matter.

In the span of about 24 hours, the magnetic field originating from the sun also began piling up, like
cars backed up on a freeway exit ramp. But scientists were able to quantify that the magnetic field
barely changed direction -- by no more than 2 degrees.

"A day made such a difference in this region with the magnetic field suddenly doubling and
becoming extraordinarily smooth," said Leonard Burlaga, the lead author of one of the papers, and
based at NASA's Goddard Space Flight Center in Greenbelt, Md. "But since there was no significant
change in the magnetic field direction, we're still observing the field lines originating at the sun."

NASA's Jet Propulsion Laboratory, in Pasadena, Calif., built and operates the Voyager spacecraft.
California Institute of Technology in Pasadena manages JPL for NASA. The Voyager missions are a
part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the
Science Mission Directorate at NASA Headquarters in Washington.

For more information about the Voyager spacecraft mission, visit: http://www.nasa.gov/voyager and
http://voyager.jpl.nasa.gov .

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Trailblazer Sea Satellite Marks its Coral Anniversary

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.jpl.nasa.gov

Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0474
alan.buis@jpl.nasa.gov

News feature: 2013-208 June 27, 2013

Trailblazer Sea Satellite Marks its Coral Anniversary

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-208&cid=release_2013-208

"The true worth of a man is not to be found in man himself, but in the colours and
textures that come alive in others."

- Albert Schweitzer

History tends to look fondly upon trailblazers, even if they don't necessarily stick around.
From musicians and actors to politicians and inventors, our lives are immeasurably
enriched by the contributions of visionaries who left us.

So when NASA's Jet Propulsion Laboratory, Pasadena, Calif., launched an
experimental satellite called Seasat to study Earth and its seas 35 years ago this week,
only to see the mission end just 106 days later due to an unexpected malfunction, some
at the time may have looked upon it as a failure. But this spunky satellite, which is still in
orbit, shining in the night sky at magnitude 4.0, continues to live on through the many
Earth and space observation missions it has spawned.

Seasat's tale began in 1969, when a group of engineers and scientists from multiple
institutions convened at a conference in Williamstown, Mass., to study how satellites
could be used to improve our understanding of the ocean. Three years later, NASA
began planning for Seasat, the first multi-sensor spacecraft dedicated specifically to
observing Earth's ocean. A broad user working group from many organizations defined
its requirements. JPL was selected to manage the project, and numerous other NASA
centers and government and industry partners participated. On the night of June 26,
1978, Seasat was launched from California's Vandenberg Air Force Base aboard an
Atlas-Agena rocket, carrying with it three prototype radar instruments and two
radiometers.

During its brief life, Seasat collected more information about ocean physics than had
been acquired in the previous 100 years of shipboard research. It established satellite
oceanography and proved the viability of several radar sensors, including an imaging
radar, for studying our planet. Most importantly, it spawned many subsequent Earth
remote-sensing satellites and instruments at JPL and elsewhere that track changes in
Earth's ocean, land and ice, including many currently in orbit or in development. Its
advances were also subsequently applied to missions to study other planets.

Post-Seasat NASA program manager Stan Wilson said Seasat demonstrated the
potential usefulness of ocean microwave observations. "As a result, at least 50 satellites
have been launched by more than a dozen space agencies to carry microwave
instruments to observe the ocean. In addition, we have two continuing records of critical
climate change in the ocean that are impacting society today: diminishing ice cover in
the Arctic and rising global sea level. What greater legacy could a mission have?"

"Seasat flew long enough to fully demonstrate its groundbreaking remote sensing
technologies, and its early death permitted the limited available resources to be
marshaled toward processing and analyzing its approximately 100-day data set," said
Bill Townsend, Seasat radar altimeter experiment manager. "This led to other systems,
both nationally and internationally, that continued Seasat's legacy, enabling Seasat
technologies to be used to better understand climate change."

Seasat's experimental instruments included a synthetic aperture radar (SAR), which
provided the first-ever highly detailed radar images of ocean and land surfaces from
space; a radar scatterometer, which measured near-surface wind speed and direction; a
radar altimeter, which measured ocean surface height, wind speed and wave heights;
and a scanning multichannel microwave radiometer that measured atmospheric and
ocean data, including wind speeds, sea ice cover, atmospheric water vapor and
precipitation, and sea surface temperatures in both clear and cloudy conditions.

On June 28, the Alaska Satellite Facility will release newly processed digital SAR
imagery from Seasat. The imagery, available for download at http://www.asf.alaska.edu
, will enable scientists to travel back in time to research the ocean, sea ice, volcanoes,
forests, land cover, glaciers and more. Before now, only about 20 percent of Seasat
SAR data had been processed digitally.

In oceanography, Seasat gave us our first global view of ocean circulation, waves and
winds, providing new insights into the links between the ocean and atmosphere that
drive our climate. For the first time, the state of an entire ocean could be seen all at
once. Seasat's altimeter, which used pulses of microwave radiation to measure the
distance from the satellite to the ocean surface precisely, mapped ocean surface
topography, allowing scientists to demonstrate how sea surface conditions could be
used to determine ocean circulation and heat storage. The data also revealed new
information about Earth's gravity field and the topography of the ocean floor.

"The short 100-day Seasat mission provided a moment of epiphany to remind people
that the vast ocean is best accessed from space," said Lee-Lueng Fu, JPL senior
research scientist and project scientist for the NASA/French Space Agency Jason-1
satellite and NASA's planned Surface Water and Ocean Topography mission.

Seasat inspired a whole generation of scientists. "I decided to take a job offer at JPL
fresh out of graduate school because I was told that the future of oceanography is in
satellite oceanography and the future of satellite oceanography will begin with Seasat at
JPL," said JPL oceanographer Tim Liu. "I did not plan to stay forever, but I have now
been here more than three decades."

Since Seasat, advanced ocean altimeters on the NASA/European Topex/Poseidon and
Jason missions have been making precise measurements of sea surface height used to
study climate phenomena such as El Niño and La Niña. The newest Jason mission,
Jason-3, is scheduled to launch in 2015 to continue the 20-plus-year climate data
record. Satellite altimetry has been used to improve weather and climate models, ship
routing, marine mammal studies, fisheries management and offshore operations.
Seasat's scatterometer gave us our first real-time global map of the speed and direction
of ocean winds, which drive waves and currents and are the major link between the
ocean and atmosphere. A scatterometer is a microwave radar sensor used to measure
the reflection or scattering effect produced while scanning the surface of Earth from an
aircraft or a satellite. The technology was later used on JPL's NASA Scatterometer,
Quikscat spacecraft, SeaWinds instrument on Japan's Midori 2 spacecraft and the
OSCAT instrument on India's Oceansat-2. It will also be used on JPL's ISS-RapidScat
instrument, launching to the International Space Station in the spring of 2014. Data from
these scatterometers, including three scatterometers launched by the European Space
Agency, help forecasters predict hurricanes, tropical storms and El Ninos.

Seasat's microwave radiometer, which subsequently flew on NASA's Nimbus-7 satellite,
led to numerous successful radiometer instruments and missions used for
oceanography, weather and climate research. Radiometers measure particular
wavelengths of microwave energy. The Seasat radiometer's heritage includes the
Special Sensor Microwave Imager instruments launched on United States Air Force
Defense Meteorological Satellite Program satellites, the joint NASA/Japanese
Aerospace Exploration Agency (JAXA) Tropical Rainfall Measuring Mission microwave
imager, the Advanced Microwave Scanning Radiometer (AMSR)-E that flew aboard
NASA's Aqua spacecraft, JAXA's current AMSR-2 instrument, and numerous other
radiometers launched by Europe, China and India. The radiometer, scatterometer and
SAR for NASA's Soil Moisture Active Passive mission to measure global soil moisture,
launching in 2014, also draw upon Seasat's heritage.

By simultaneously flying a radiometer with a radar altimeter, Seasat demonstrated the
benefit of using radiometer measurements of water vapor to correct altimeter
measurements of sea surface height. Water vapor affects the accuracy of altimeter
measurements by delaying the time it takes for the altimeter's signals to make their
round trip to the ocean surface and back. This technique has been used on all
subsequent NASA/European satellite altimetry missions.

Seasat's oceanographic mission also studied sea ice and its role in controlling Earth's
climate. Its SAR provided the first high-resolution images of sea ice, measuring its
movement, deformation and age. Today, SAR and scatterometers are also used to
monitor Earth's ice from space.

"It's hard to imagine where we would be without the radiometer pioneered on Seasat,
but certainly much further behind in critical Earth observations than we are now," said
Gary Lagerloef of Earth & Space Research, Seattle, principal investigator of NASA's
Aquarius mission to map ocean surface salinity. The Aquarius radiometer and
scatterometer also trace their heritage back to Seasat.

Seasat's SAR monitored the global surface wave field and revealed many oceanic- and
atmospheric-related phenomena, from current boundaries to eddies and internal waves.

Beyond the ocean, Seasat's SAR provided spectacular images of Earth's land surfaces
and geology. Seasat data were used to pioneer radar interferometry, which uses
microwave energy pulses sent from sensors on satellites or aircraft to the ground to
detect land surface changes such as those created by earthquakes, and measure land
surface topography. Three JPL Shuttle Imaging Radar experiments flew on the Space
Shuttle in the 1980s/1990s. In 2000, JPL's Shuttle Radar Topography Mission used the
technology to create the world's most detailed topographic measurements of more than
80 percent of Earth's land surface. Today, the technology is being used on JPL's
Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne imaging radar
system for a wide variety of Earth studies. Among the international SAR missions with
heritages tracing to Seasat are the Japanese Earth Resources Satellite 1 and Advanced
Land Observing System 1, the Canadian/U.S. Radarsat 1 and the European Space
Agency's Remote Sensing Satellites. The technology will also be used on NASA's
planned Surface Water and Ocean Topography mission, planned for launch in 2020.

Paul Rosen, JPL project scientist for a future NASA L-band SAR spacecraft currently
under study, said Seasat's demonstration of spaceborne repeat-pass radar
interferometry to measure minute Earth surface motions has led to a new field of space
geodetic imaging and forms the basis for his new mission.

"Together with international L-band SAR sensors, we have the opportunity in the next
five years to create a 40-year observation record of land-use change where overlapping
observations exist," Rosen said. "These time-lapse images of change will provide
fascinating insights into urban growth, agricultural patterns and other signs of human-
induced changes over decades and climate change in the polar regions."

Beyond Earth, Seasat technology was used on JPL's Magellan mission, which mapped
99 percent of the previously hidden surface of Venus, and the Titan radar onboard the
JPL-built and -managed Cassini orbiter to Saturn.

Seasat was managed by JPL for NASA, with significant participation from NASA's
Goddard Space Flight Center, Greenbelt, Md.; NASA's Wallops Flight Facility, Wallops
Island, Va.; NASA's Langley Research Center, Hampton, Va.; NASA's Glenn Research
Center, Cleveland, Ohio; Johns Hopkins University Applied Physics Laboratory, Laurel,
Md.; Lockheed Missiles and Space Systems, Sunnyvale, Calif.; and NOAA,
Washington, D.C.

For more on Seasat, visit: http://podaac.jpl.nasa.gov/SeaSAT and
http://www.jpl.nasa.gov/multimedia/seasat/intro.html . JPL is a division of the California
Institute of Technology, Pasadena.

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Friday, June 21, 2013

NASA Announces Winners of 2012 George M. Low Award

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Beth Dickey 202-358-2087
NASA Headquarters, Washington
beth.dickey-1@nasa.gov

News release: 2013-206 June 21, 2013

NASA Announces Winners of 2012 George M. Low Award

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-206&cid=release_2013-206

WASHINGTON -- Two companies that share a commitment to teamwork, technical and managerial
excellence, safety, and customer service have been selected to receive NASA's premier honor for
quality and performance, the George M. Low Award.

NASA recognizes URS Federal Technical Services Inc. of Germantown, Md., in the large business
award category and ATA Engineering Inc. of San Diego in the small business award category. ATA
Engineering Inc. was involved in the Mars Science Laboratory/Curiosity mission.

"NASA's industry partners are crucial in our work to reach new destinations and expand our nation's
capabilities, and we're happy to recognize these two companies with the high honor of the George M.
Low Award," said NASA Administrator Charles Bolden. "Their success both in space and on the
ground has demonstrated excellence and innovation that will help us reach our challenging goals and
keep America the leader in space exploration."

URS Federal Technical Services Inc. is the institutional services contractor at NASA's Kennedy
Space Center in Florida. With 1,100 employees and subcontractors, the company maintains 1,250
facilities, roadways, railroad tracks and an airfield; provides utilities, indoor climate control, life
support and propellant storage; conducts non-destructive evaluation; cleans, samples and calibrates
components; and coordinates logistics.

Evaluators cited URS' automation initiative, which deployed tablet computers to employees to reduce
their paperwork burden; its process for ensuring customer satisfaction; and the breadth of its safety
program in an industrial environment with so many potential hazards.

ATA Engineering Inc. supported development of the Mars Science Laboratory and its robotic rover,
Curiosity, at NASA's Jet Propulsion Laboratory in Pasadena, Calif. With 93 employees, the company
played a key role in the mission by conducting detailed mechanical simulation work to support
spacecraft's challenging entry, descent and landing at Mars in August last year.

Evaluators cited ATA's problem-solving ability, demonstrated with the design of Curiosity's sampling
scoop; its emphasis on contracting with small business and hiring young talent with high potential;
and its strong culture of teamwork.

"I congratulate these companies for winning our premier award. It's our recognition for their
management's leadership and employee commitment to the highest standards in performance," said
Terrence Wilcutt, the agency's chief of safety and mission assurance. "For NASA to do the kind of
things the country asks us to do in exploration, science, research, and technology development, we
depend on our contractors to operate at an exemplary level. URS Federal Technical Services Inc. and
ATA Engineering Inc. have set the example for all of us."

The Low award demonstrates the agency's commitment to promoting excellence and continual
improvement by challenging NASA's contractor community to be a global benchmark of quality
management practices.

The award was established in 1985 as NASA's Excellence Award for Quality and Productivity. It was
renamed in 1990 in memory of George M. Low, an outstanding leader with a strong commitment to
quality products and workforce during his 27-year tenure at the agency. Low was NASA's deputy
administrator from 1969 to 1976 and a leader in the early development of space programs.

For more information about the George M. Low Award, visit:

http://www.hq.nasa.gov/office/codeq/gml

For information about NASA and agency programs, visit:

http://www.nasa.gov

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science
Laboratory Project, of which Curiosity is the centerpiece, for NASA's Science Mission Directorate in
Washington.

For more information about the Curiosity Mars rover, visit: http://www.nasa.gov/msl and
http://mars.jpl.nasa.gov/msl . To follow the mission on Facebook and Twitter visit:
http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity .

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Wednesday, June 19, 2013

Billion-Pixel View of Mars Comes From Curiosity Rover

Tuesday, June 18, 2013

Cassini Probe to Take Photo of Earth From Deep Space

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.jpl.nasa.gov

Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

News release: 2013-204 June 18, 2013

Cassini Probe to Take Photo of Earth From Deep Space

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-204&cid=release_2013-204

PASADENA, Calif. – NASA's Cassini spacecraft, now exploring Saturn, will take a picture of our
home planet from a distance of hundreds of millions of miles on July 19. NASA is inviting the public
to help acknowledge the historic interplanetary portrait as it is being taken.

Earth will appear as a small, pale blue dot between the rings of Saturn in the image, which will be
part of a mosaic, or multi-image portrait, of the Saturn system Cassini is composing.

"While Earth will be only about a pixel in size from Cassini's vantage point 898 million [1.44 billion
kilometers] away, the team is looking forward to giving the world a chance to see what their home
looks like from Saturn," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion
Laboratory in Pasadena, Calif. "We hope you'll join us in waving at Saturn from Earth, so we can
commemorate this special opportunity."

Cassini will start obtaining the Earth part of the mosaic at 2:27 p.m. PDT (5:27 p.m. EDT or 21:27
UTC) and end about 15 minutes later, all while Saturn is eclipsing the sun from Cassini's point of
view. The spacecraft's unique vantage point in Saturn's shadow will provide a special scientific
opportunity to look at the planet's rings. At the time of the photo, North America and part of the
Atlantic Ocean will be in sunlight.

Unlike two previous Cassini eclipse mosaics of the Saturn system in 2006, which captured Earth, and
another in 2012, the July 19 image will be the first to capture the Saturn system with Earth in natural
color, as human eyes would see it. It also will be the first to capture Earth and its moon with Cassini's
highest-resolution camera. The probe's position will allow it to turn its cameras in the direction of the
sun, where Earth will be, without damaging the spacecraft's sensitive detectors.

"Ever since we caught sight of the Earth among the rings of Saturn in September 2006 in a mosaic
that has become one of Cassini's most beloved images, I have wanted to do it all over again, only
better," said Carolyn Porco, Cassini imaging team lead at the Space Science Institute in Boulder,
Colo. "This time, I wanted to turn the entire event into an opportunity for everyone around the globe
to savor the uniqueness of our planet and the preciousness of the life on it."

Porco and her imaging team associates examined Cassini's planned flight path for the remainder of its
Saturn mission in search of a time when Earth would not be obstructed by Saturn or its rings.
Working with other Cassini team members, they found the July 19 opportunity would permit the
spacecraft to spend time in Saturn's shadow to duplicate the views from earlier in the mission to
collect both visible and infrared imagery of the planet and its ring system.

"Looking back towards the sun through the rings highlights the tiniest of ring particles, whose width
is comparable to the thickness of hair and which are difficult to see from ground-based telescopes,"
said Matt Hedman, a Cassini science team member based at Cornell University in Ithaca, N.Y., and a
member of the rings working group. "We're particularly interested in seeing the structures within
Saturn's dusty E ring, which is sculpted by the activity of the geysers on the moon Enceladus, Saturn's
magnetic field and even solar radiation pressure."

This latest image will continue a NASA legacy of space-based images of our fragile home, including
the 1968 "Earthrise" image taken by the Apollo 8 moon mission from about 240,000 miles (380,000
kilometers) away and the 1990 "Pale Blue Dot" image taken by Voyager 1 from about 4 billion miles
(6 billion kilometers) away.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the
Italian Space Agency. JPL manages the Cassini-Huygens mission for NASA's Science Mission
Directorate in Washington, and designed, developed and assembled the Cassini orbiter and its two
onboard cameras. The imaging team consists of scientists from the United States, the United
Kingdom, France and Germany. The imaging operations center is based at the Space Science Institute
in Boulder, Colo.

To learn more about the public outreach activities associated with the taking of the image, visit:
http://saturn.jpl.nasa.gov/waveatsaturn .

For more information about Cassini, visit http://www.nasa.gov/cassini and
http://saturn.jpl.nasa.gov .

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Thursday, June 13, 2013

Warm Ocean Causing Most Antarctic Ice Shelf Mass Loss

Wednesday, June 12, 2013

Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

News release: 2013-201 June 12, 2013

Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-201&cid=release_2013-201

PASADENA, Calif. -- Researchers using NASA's Mars Reconnaissance Orbiter have found that
temperatures in the Martian atmosphere regularly rise and fall not just once each day, but twice.

"We see a temperature maximum in the middle of the day, but we also see a temperature
maximum a little after midnight," said Armin Kleinboehl of NASA's Jet Propulsion Laboratory
in Pasadena, Calif., who is the lead author of a new report on these findings.

Temperatures swing by as much as 58 degrees Fahrenheit (32 kelvins) in this odd, twice-a-day
pattern, as detected by the orbiter's Mars Climate Sounder instrument.

The new set of Mars Climate Sounder observations sampled a range of times of day and night all
over Mars. The observations found that the pattern is dominant globally and year-round. The
report is being published in the journal Geophysical Research Letters.

Global oscillations of wind, temperature and pressure repeating each day or fraction of a day are
called atmospheric tides. In contrast to ocean tides, they are driven by variation in heating
between day and night. Earth has atmospheric tides, too, but the ones on Earth produce little
temperature difference in the lower atmosphere away from the ground. On Mars, which has only
about one percent as much atmosphere as Earth, they dominate short-term temperature variations
throughout the atmosphere.

Tides that go up and down once per day are called "diurnal." The twice-a-day ones are called
"semi-diurnal." The semi-diurnal pattern on Mars was first seen in the 1970s, but until now it had
been thought to appear just in dusty seasons, related to sunlight warming dust in the atmosphere.

"We were surprised to find this strong twice-a-day structure in the temperatures of the non-dusty
Mars atmosphere," Kleinboehl said. "While the diurnal tide as a dominant temperature response
to the day-night cycle of solar heating on Mars has been known for decades, the discovery of a
persistent semi-diurnal response even outside of major dust storms was quite unexpected, and
caused us to wonder what drove this response."

He and his four co-authors found the answer in the water-ice clouds of Mars. The Martian
atmosphere has water-ice clouds for most of the year. Clouds in the equatorial region between
about 6 to 19 miles (10 to 30 kilometers) above the surface of Mars absorb infrared light emitted
from the surface during daytime. These are relatively transparent clouds, like thin cirrus clouds
on Earth. Still, the absorption by these clouds is enough to heat the middle atmosphere each day.
The observed semi-diurnal temperature pattern, with its maximum temperature swings occurring
away from the tropics, was also unexpected, but has been replicated in Mars climate models
when the radiative effects of water-ice clouds are included.

"We think of Mars as a cold and dry world with little water, but there is actually more water
vapor in the Martian atmosphere than in the upper layers of Earth's atmosphere," Kleinboehl
said. "Water-ice clouds have been known to form in regions of cold temperatures, but the
feedback of these clouds on the Mars temperature structure had not been appreciated. We know
now that we will have to consider the cloud structure if we want to understand the Martian
atmosphere. This is comparable to scientific studies concerning Earth's atmosphere, where we
have to better understand clouds to estimate their influence on climate."

JPL, a division of the California Institute of Technology in Pasadena, provided the Mars Climate
Sounder instrument and manages the Mars Reconnaissance Orbiter project for NASA's Science
Mission Directorate, Washington.

For more about the Mars Reconnaissance Orbiter, visit: http://www.nasa.gov/mro .

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Tuesday, June 11, 2013

Marks on Martian Dunes May Be Tracks of Dry-Ice Sleds

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE 818-354-5011
http://www.jpl.nasa.gov

Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown@nasa.gov

News release: 2013-200 June 11, 2013

Marks on Martian Dunes May Be Tracks of Dry-Ice Sleds

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-200&cid=release_2013-200

PASADENA, Calif. -- NASA research indicates hunks of frozen carbon dioxide -- dry ice -- may
glide down some Martian sand dunes on cushions of gas similar to miniature hovercraft, plowing
furrows as they go.

Researchers deduced this process could explain one enigmatic class of gullies seen on Martian sand
dunes by examining images from NASA's Mars Reconnaissance Orbiter (MRO) and performing
experiments on sand dunes in Utah and California.

"I have always dreamed of going to Mars," said Serina Diniega, a planetary scientist at NASA's Jet
Propulsion Laboratory in Pasadena, Calif., and lead author of a report published online by the journal
Icarus. "Now I dream of snowboarding down a Martian sand dune on a block of dry ice."

The hillside grooves on Mars, called linear gullies, show relatively constant width -- up to a few
yards, or meters, across -- with raised banks or levees along the sides. Unlike gullies caused by water
flows on Earth and possibly on Mars, they do not have aprons of debris at the downhill end of the
gully. Instead, many have pits at the downhill end.

"In debris flows, you have water carrying sediment downhill, and the material eroded from the top is
carried to the bottom and deposited as a fan-shaped apron," said Diniega. "In the linear gullies, you're
not transporting material. You're carving out a groove, pushing material to the sides."

Images from MRO's High Resolution Imaging Science Experiment (HiRISE) camera show sand
dunes with linear gullies covered by carbon-dioxide frost during the Martian winter. The location of
the linear gullies is on dunes that spend the Martian winter covered by carbon-dioxide frost. By
comparing before-and-after images from different seasons, researchers determined that the grooves
are formed during early spring. Some images have even caught bright objects in the gullies.

Scientists theorize the bright objects are pieces of dry ice that have broken away from points higher
on the slope. According to the new hypothesis, the pits could result from the blocks of dry ice
completely sublimating away into carbon-dioxide gas after they have stopped traveling.

"Linear gullies don't look like gullies on Earth or other gullies on Mars, and this process wouldn't
happen on Earth," said Diniega. "You don't get blocks of dry ice on Earth unless you go buy them."

That is exactly what report co-author Candice Hansen, of the Planetary Science Institute in Tucson,
Ariz., did. Hansen has studied other effects of seasonal carbon-dioxide ice on Mars, such as spider-
shaped features that result from explosive release of carbon-dioxide gas trapped beneath a sheet of
dry ice as the underside of the sheet thaws in spring. She suspected a role for dry ice in forming linear
gullies, so she bought some slabs of dry ice at a supermarket and slid them down sand dunes.

That day and in several later experiments, gaseous carbon dioxide from the thawing ice maintained a
lubricating layer under the slab and also pushed sand aside into small levees as the slabs glided down
even low-angle slopes.

The outdoor tests did not simulate Martian temperature and pressure, but calculations indicate the dry
ice would act similarly in early Martian spring where the linear gullies form. Although water ice, too,
can sublimate directly to gas under some Martian conditions, it would stay frozen at the temperatures
at which these gullies form, the researchers calculate.

"MRO is showing that Mars is a very active planet," Hansen said. "Some of the processes we see on
Mars are like processes on Earth, but this one is in the category of uniquely Martian."

Hansen also noted the process could be unique to the linear gullies described on Martian sand dunes.

"There are a variety of different types of features on Mars that sometimes get lumped together as
'gullies,' but they are formed by different processes," she said. "Just because this dry-ice hypothesis
looks like a good explanation for one type doesn't mean it applies to others."

The University of Arizona Lunar and Planetary Laboratory operates the HiRISE camera, which was
built by Ball Aerospace & Technologies Corp. of Boulder, Colo. JPL, a division of the California
Institute of Technology in Pasadena, manages MRO for NASA's Science Mission Directorate in
Washington. Lockheed Martin Space Systems, Denver, built the orbiter.

To see images of the linear gullies and obtain more information about MRO, visit:
http://www.nasa.gov/mro .

For more about HiRISE, visit: http://hirise.lpl.arizona.edu .

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Shining a Light on Cool Pools of Gas in the Galaxy

Black Hole Naps Amidst Stellar Chaos

Monday, June 10, 2013

Is a Sleeping Climate Giant Stirring in the Arctic?

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.jpl.nasa.gov

Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov

News feature: 2013-197 June 10, 2013

Is a Sleeping Climate Giant Stirring in the Arctic?

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-197&cid=release_2013-197

Flying low and slow above the wild, pristine terrain of Alaska's North Slope in a
specially instrumented NASA plane, research scientist Charles Miller of NASA's
Jet Propulsion Laboratory, Pasadena, Calif., surveys the endless whiteness of
tundra and frozen permafrost below. On the horizon, a long, dark line appears.
The plane draws nearer, and the mysterious object reveals itself to be a massive
herd of migrating caribou, stretching for miles. It's a sight Miller won't soon forget.

"Seeing those caribou marching single-file across the tundra puts what we're
doing here in the Arctic into perspective," said Miller, principal investigator of the
Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), a five-year
NASA-led field campaign studying how climate change is affecting the Arctic's
carbon cycle.

"The Arctic is critical to understanding global climate," he said. "Climate change
is already happening in the Arctic, faster than its ecosystems can adapt. Looking
at the Arctic is like looking at the canary in the coal mine for the entire Earth
system."

Aboard the NASA C-23 Sherpa aircraft from NASA's Wallops Flight Facility,
Wallops Island, Va., Miller, CARVE Project Manager Steve Dinardo of JPL and
the CARVE science team are probing deep into the frozen lands above the Arctic
Circle. The team is measuring emissions of the greenhouse gases carbon
dioxide and methane from thawing permafrost -- signals that may hold a key to
Earth's climate future.

What Lies Beneath

Permafrost (perennially frozen) soils underlie much of the Arctic. Each summer,
the top layers of these soils thaw. The thawed layer varies in depth from about 4
inches (10 centimeters) in the coldest tundra regions to several yards, or meters,
in the southern boreal forests. This active soil layer at the surface provides the
precarious foothold on which Arctic vegetation survives. The Arctic's extremely
cold, wet conditions prevent dead plants and animals from decomposing, so
each year another layer gets added to the reservoirs of organic carbon
sequestered just beneath the topsoil.

Over hundreds of millennia, Arctic permafrost soils have accumulated vast stores
of organic carbon – an estimated 1,400 to 1,850 petagrams of it (a petagram is
2.2 trillion pounds, or 1 billion metric tons). That's about half of all the estimated
organic carbon stored in Earth's soils. In comparison, about 350 petagrams of
carbon have been emitted from all fossil-fuel combustion and human activities
since 1850. Most of this carbon is located in thaw-vulnerable topsoils within 10
feet (3 meters) of the surface.

But, as scientists are learning, permafrost – and its stored carbon – may not be
as permanent as its name implies. And that has them concerned.

"Permafrost soils are warming even faster than Arctic air temperatures – as much
as 2.7 to 4.5 degrees Fahrenheit (1.5 to 2.5 degrees Celsius) in just the past 30
years," Miller said. "As heat from Earth's surface penetrates into permafrost, it
threatens to mobilize these organic carbon reservoirs and release them into the
atmosphere as carbon dioxide and methane, upsetting the Arctic's carbon
balance and greatly exacerbating global warming."

Current climate models do not adequately account for the impact of climate
change on permafrost and how its degradation may affect regional and global
climate. Scientists want to know how much permafrost carbon may be vulnerable
to release as Earth's climate warms, and how fast it may be released.

CARVing Out a Better Understanding of Arctic Carbon

Enter CARVE. Now in its third year, this NASA Earth Ventures program
investigation is expanding our understanding of how the Arctic's water and
carbon cycles are linked to climate, as well as what effects fires and thawing
permafrost are having on Arctic carbon emissions. CARVE is testing hypotheses
that Arctic carbon reservoirs are vulnerable to climate warming, while delivering
the first direct measurements and detailed regional maps of Arctic carbon dioxide
and methane sources and demonstrating new remote sensing and modeling
capabilities. About two dozen scientists from 12 institutions are participating.

"The Arctic is warming dramatically – two to three times faster than mid-latitude
regions – yet we lack sustained observations and accurate climate models to
know with confidence how the balance of carbon among living things will respond
to climate change and related phenomena in the 21st century," said Miller.
"Changes in climate may trigger transformations that are simply not reversible
within our lifetimes, potentially causing rapid changes in the Earth system that
will require adaptations by people and ecosystems."

The CARVE team flew test flights in 2011 and science flights in 2012. This April
and May, they completed the first two of seven planned monthly campaigns in
2013, and they are currently flying their June campaign.

Each two-week flight campaign across the Alaskan Arctic is designed to capture
seasonal variations in the Arctic carbon cycle: spring thaw in April/May, the peak
of the summer growing season in June/July, and the annual fall refreeze and first
snow in September/October. From a base in Fairbanks, Alaska, the C-23 flies up
to eight hours a day to sites on Alaska's North Slope, interior and Yukon River
Valley over tundra, permafrost, boreal forests, peatlands and wetlands.

The C-23 won't win any beauty contests – its pilots refer to it as "a UPS truck
with a bad nose job." Inside, it's extremely noisy – the pilots and crew wear
noise-cancelling headphones to communicate. "When you take the headphones
off, it's like being at a NASCAR race," Miller quipped.

But what the C-23 lacks in beauty and quiet, it makes up for in reliability and its
ability to fly "down in the mud," so to speak. Most of the time, it flies about 500
feet (152 meters) above ground level, with periodic ascents to higher altitudes to
collect background data. Most airborne missions measuring atmospheric carbon
dioxide and methane do not fly as low. "CARVE shows you need to fly very close
to the surface in the Arctic to capture the interesting exchanges of carbon taking
place between Earth's surface and atmosphere," Miller said.

Onboard the plane, sophisticated instruments "sniff" the atmosphere for
greenhouse gases. They include a very sensitive spectrometer that analyzes
sunlight reflected from Earth's surface to measure atmospheric carbon dioxide,
methane and carbon monoxide. This instrument is an airborne simulator for
NASA's Orbiting Carbon Observatory-2 (OCO-2) mission to be launched in 2014.
Other instruments analyze air samples from outside the plane for the same
chemicals. Aircraft navigation data and basic weather data are also collected.
Initial data are delivered to scientists within 12 hours. Air samples are shipped to
the University of Colorado's Institute for Arctic and Alpine Research Stable
Isotope Laboratory and Radiocarbon Laboratory in Boulder for analyses to
determine the carbon's sources and whether it came from thawing permafrost.

Much of CARVE's science will come from flying at least three years, Miller says.
"We are showing the power of using dependable, low-cost prop planes to make
frequent, repeat measurements over time to look for changes from month to
month and year to year."

Ground observations complement the aircraft data and are used to calibrate and
validate them. The ground sites serve as anchor points for CARVE's flight tracks.
Ground data include air samples from tall towers and measurements of soil
moisture and temperature to determine whether soil is frozen, thawed or flooded.

A Tale of Two Greenhouse Gases

It's important to accurately characterize the soils and state of the land surfaces.
There's a strong correlation between soil characteristics and release of carbon
dioxide and methane. Historically, the cold, wet soils of Arctic ecosystems have
stored more carbon than they have released. If climate change causes the Arctic
to get warmer and drier, scientists expect most of the carbon to be released as
carbon dioxide. If it gets warmer and wetter, most will be in the form of methane.

The distinction is critical. Molecule per molecule, methane is 22 times more
potent as a greenhouse gas than carbon dioxide on a 100-year timescale, and
105 times more potent on a 20-year timescale. If just one percent of the
permafrost carbon released over a short time period is methane, it will have the
same greenhouse impact as the 99 percent that is released as carbon dioxide.
Characterizing this methane to carbon dioxide ratio is a major CARVE objective.

There are other correlations between Arctic soil characteristics and the release of
carbon dioxide and methane. Variations in the timing of spring thaw and the
length of the growing season have a major impact on vegetation productivity and
whether high northern latitude regions generate or store carbon.

CARVE is also studying wildfire impacts on the Arctic's carbon cycle. Fires in
boreal forests or tundra accelerate the thawing of permafrost and carbon release.
Detailed fire observation records since 1942 show the average annual number of
Alaska wildfires has increased, and fires with burn areas larger than 100,000
acres are occurring more frequently, trends scientists expect to accelerate in a
warming Arctic. CARVE's simultaneous measurements of greenhouse gases will
help quantify how much carbon is released to the atmosphere from fires in
Alaska – a crucial and uncertain element of its carbon budget.

Early Results

The CARVE science team is busy analyzing data from its first full year of science
flights. What they're finding, Miller said, is both amazing and potentially troubling.

"Some of the methane and carbon dioxide concentrations we've measured have
been large, and we're seeing very different patterns from what models suggest,"
Miller said. "We saw large, regional-scale episodic bursts of higher-than-normal
carbon dioxide and methane in interior Alaska and across the North Slope during
the spring thaw, and they lasted until after the fall refreeze. To cite another
example, in July 2012 we saw methane levels over swamps in the Innoko
Wilderness that were 650 parts per billion higher than normal background levels.
That's similar to what you might find in a large city."

Ultimately, the scientists hope their observations will indicate whether an
irreversible permafrost tipping point may be near at hand. While scientists don't
yet believe the Arctic has reached that tipping point, no one knows for sure. "We
hope CARVE may be able to find that 'smoking gun,' if one exists," Miller said.

Other institutions participating in CARVE include City College of New York; the
joint University of Colorado/National Oceanic and Atmospheric Administration's
Cooperative Institute for Research in Environmental Sciences, Boulder, Colo.;
San Diego State University; University of California, Irvine; California Institute of
Technology, Pasadena; Harvard University, Cambridge, Mass.; University of
California, Berkeley; Lawrence Berkeley National Laboratory, Berkeley, Calif.;
University of California, Santa Barbara; NOAA's Earth System Research
Laboratory, Boulder, Colo.; and University of Melbourne, Victoria, Australia.

For more information on CARVE, visit:
http://science.nasa.gov/missions/carve/ .

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Friday, June 7, 2013

Hidden Wildfires Taking Big Toll on Amazon Rainforest

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 PHONE 818-354-5011
http://www.jpl.nasa.gov

Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov

2013-196

News release: 2013-196 June 7, 2013

Hidden Wildfires Taking Big Toll on Amazon Rainforest

The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.php?release=2013-196&cid=release_2013-196

Using an innovative satellite technique, NASA scientists have determined that a previously unmapped type of wildfire in the Amazon rainforest is responsible for destroying several times more forest than has been lost through deforestation in recent years.

In the southern Amazon rainforest, fires below the forest treetops, or "understory fires," have been hidden from view from NASA satellites that detect actively burning fires. The new method has now led to the first regional estimate of understory fire damages across the southern Amazon.

"Amazon forests are quite vulnerable to fire, given the frequency of ignitions for deforestation and land management at the forest frontier, but we've never known the regional extent or frequency of these understory fires," said Doug Morton of NASA's Goddard Space Flight Center in Greenbelt, Md., and the study's lead author. The study was published April 22 in Philosophical Transactions of the Royal Society B.

In years with the most understory fire activity, such as 2005, 2007 and 2010, the area of forest affected by understory fires was several times greater than the area of deforestation for expansion of agriculture, according to Morton. The study goes further and fingers climate conditions - not deforestation - as the most important factor in determining fire risk in the Amazon at a regional scale.

Uncovering the Story Behind Understory Fires

Fires in the Amazon's savanna areas can burn quickly, spreading up to 330 feet (100 meters) per minute. Grasses and shrubs in these ecosystems typically survive low-intensity surface fires.

In contrast, understory fires at the frontier and beyond appear "unremarkable when you see them burning," Morton said. Flames reach on average only a few feet high, visible from the air as ribbons of smoke that escape through the canopy. They may burn for weeks at a time, spreading only a few feet (0.5 meters) per minute.

Understory fires, however, can damage large areas because Amazon trees are not adapted to fire. The long, slow burn gives way to a creeping death that claims anywhere from 10 to 50 percent of the burn area's trees. Recovery is also a long and slow, but observable, process.

To identify understory fires, Morton and colleagues used observations from early in the dry season, from June to August, collected by the Moderate Resolution Imaging Spectroradiometer, or MODIS, instrument on NASA's Terra satellite. They tracked the timing of fire damage and recovery, which varies depending on the type of forest disturbance. Areas of deforestation, for example, show up in satellite imagery as land that continues to lack signs of recovery for at least two consecutive years. Conversely, signs of forest degradation from understory fires, visible in the year after the burn, dissipate quickly as the forest regrows. This pattern of damage and recovery over multiple years provides a fingerprint of understory fire damages in Amazon forests.

The study shows that between 1999 and 2010, understory forest fires burned more than 33,000 square miles (85,500 square kilometers), or 2.8 percent of the forest. Results also show no correlation between understory fires and deforestation. As the pressure for clearing led to the highest deforestation rates ever seen from 2003 to 2004, adjacent forests had some of the lowest rates of fires.

"You would think that deforestation activity would significantly increase the risk of fires in the adjacent forested area because deforestation fires are massive, towering infernos," Morton said. "You make a bonfire that is a square kilometer in size, throwing ash and live cinders and preheating the adjacent forest. Why didn't we have more understory fires in 2003 and 2004, when deforestation rates were so high?"

The researchers point to climate as the reason that fire-driven deforestation didn't burn more surrounding forests in these years. Frequent understory fire activity coincides with low nighttime humidity, as measured by the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's Aqua satellite. Scientists say the connection points to a strong climate control on Amazon fires.

"You can look within an indigenous reserve where there is no deforestation and see enormous understory fires," Morton said. "The human presence at the deforestation frontier leads to a risk of forest fires when climate conditions are suitable for burning, with or without deforestation activity."

Ignition could come from cooking, camping, cigarettes, cars, agricultural waste burning or any number of human sources.

The new knowledge about the scope of understory fires could have implications for estimates of carbon emissions from disturbed forests. How experts account for those emissions depends on the fate of the forest - how it is disturbed and how it recovers.

"We don't yet have a robust estimate of what the net carbon emissions are from understory fires, but widespread damages suggest that they are important source of emissions that we need to consider," Morton said.

For now, scientists are looking into the climate mechanisms that, given an ignition source from humans, predispose the southern Amazon to burn.

Soil Moisture as a Fire Indicator

Already, scientists at the University of California, Irvine, have delved deeper into the climate-fire connection. New research shows that satellite-based measurements of the region's soil moisture could supplement and sharpen fire season forecasts across the southern Amazon.

The first forecast in 2012 and new forecast for 2013, led by Jim Randerson at UC Irvine, are based on a model that primarily considers historical fire data from MODIS instruments along with sea surface temperature data from NOAA. Previous research has shown sea surface temperature to be a good indicator of the pending Amazon fire season severity.

Now, scientists are interested in fine-tuning the model across smaller geographic regions and finer timescales. Toward that goal, Yang Chen of UC Irvine and colleagues show that water storage estimates from NASA's Gravity Recovery and Climate Experiment, or GRACE, satellites allow monitoring of the evolution of dry conditions during the fire season.

Transpiration and evaporation are two ways that water is transported from the ground to the atmosphere. Low water storage in the soil leads to a drier near-ground atmosphere. The result is drier, more flammable vegetation alongside increases in plant litter and fuel availability. Chen's research was published online April 11 in the American Geophysical Union's Journal of Geophysical Research - Biogeosciences.

"A severe fire season in the Amazon is often preceded by low water storage in the soil, and this water deficit in the soil can be detected by the satellites several months before the fire season," Chen said.

Soil water storage in the southern Amazon in June is a key indicator of fire season severity. "The GRACE measurements provide unique and precise information about land water storage that changes completely the way we can look at fire prediction," said Isabella Velicogna of UC Irvine and NASA's Jet Propulsion Laboratory in Pasadena, Calif., who lead the GRACE analysis.

While the water storage estimates are not yet officially part of Randerson and colleagues' forecasts, the study "charts the course forward to leverage GRACE data for operational purposes," Morton said. "The ability to integrate observations from many different NASA instruments is really a hallmark of Earth system science. In this case, the science also has important, practical applications to mitigating the impacts of fires on the Amazon region and global climate."

For more information, see: http://www.nasa.gov/topics/earth/features/amazon-fire-risk.html. To read a new assessment by university and NASA researchers of the current outlook for Amazon forest fire risk in the 2013 fire season, visit: http://www.nasa.gov/topics/earth/features/2013-fire-year.html.

GRACE is a joint mission with the German Aerospace Center and the German Research Center for Geosciences, in partnership with the University of Texas at Austin. For more about GRACE, visit: http://www.nasa.gov/grace and http://www.csr.utexas.edu/grace. JPL developed the GRACE spacecraft and manages the mission for NASA's Science Mission Directorate, Washington. The California Institute of Technology in Pasadena manages JPL for NASA.

Written by Kathryn Hansen
NASA's Earth Science News Team

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