NASA : NASA Begins Sixth Year of Airborne Antarctic Ice Change Study

Hola amigos: AL VUELO DE UN QUINDE EL BLOG., la Agencia Espacial NASA, nos informa sobre sus estudios en la Antártica sobre que  comienza Sexto Año de Airborne Antártida Estudio Cambio de Hielo. Ellos dicen..."NASA está llevando a cabo su sexto año consecutivo de vuelos de investigación Operación IceBridge sobre la Antártida para estudiar los cambios en la capa de hielo del continente, glaciares y hielo marino. Campaña aérea de este año, que comenzó su primer vuelo la mañana del jueves, volverá a examinar una sección de la capa de hielo de la Antártida que hace poco se encontró que en un declive irreversible.........

Para las próximas semanas, los investigadores volarán a bordo de aviones de investigación de la NASA DC-8 de Punta Arenas, Chile. Este año también marca el regreso de la Antártida occidental tras la campaña de 2013 con base en la estación McMurdo de la Fundación Nacional de Ciencia.....

NASA’s DC-8 research aircraft will be flying scientists and instruments over Antarctica to study changes in the continent’s ice sheet, glaciers and sea ice.

Image Credit: 

NASA

 

NASA is carrying out its sixth consecutive year of Operation IceBridge research flights over Antarctica to study changes in the continent’s ice sheet, glaciers and sea ice. This year’s airborne campaign, which began its first flight Thursday morning, will revisit a section of the Antarctic ice sheet that recently was found to be in irreversible decline.

For the next several weeks, researchers will fly aboard NASA’s DC-8 research aircraft out of Punta Arenas, Chile. This year also marks the return to western Antarctica following 2013’s campaign based at the National Science Foundation’s McMurdo Station.

“We are curious to see how much these glaciers have changed in two years,” said Eric Rignot, IceBridge science team co-lead and glaciologist at the University of California, Irvine and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

IceBridge will use a suite of instruments that includes a laser altimeter, radar instruments, cameras, and a gravimeter, which is an instrument that detects small changes in gravity. These small changes reveal how much mass these glaciers have lost. Repeated annual measurements of key glaciers maintains a long-term record of change in the Antarctic that goes back to NASA’s Ice, Cloud and Land Elevation Satellite (ICESat) which stopped collecting data in 2009.

IceBridge researchers plan to measure previously unsurveyed regions of Antarctica. One example is a plan to look at the upper portions of Smith Glacier in West Antarctica, which is thinning faster than any other glaciers in the region. The mission also plans to collect data in portions of the Antarctic Peninsula, such as the Larsen C, George VI and Wilkins ice shelves and the glaciers that drain into them. The Antarctic Peninsula has been warming faster than the rest of the continent.

“The Antarctic Peninsula is changing fairly rapidly and we need to be there to capture that change,” said Michael Studinger, IceBridge project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The mission also will collect data on Antarctic sea ice, which recently reached a record high coverage. This contrasts with declining sea ice in the Arctic and is due do a variety of factors such as changing wind patterns. Antarctic sea ice coverage is slightly above average and the growth varies from one part of Antarctica to another. For example, ice cover in the Bellingshausen Sea has been decreasing while ice in the nearby Ross Sea is growing.

“There are very strong regional variations on how sea ice is changing,” said Nathan Kurtz, a sea ice scientist at Goddard. These regional trends together yield a small increase, so studying each region will help scientists get a better grasp on the processes affecting sea ice there.

In addition to extending ICESat’s data record over land and sea ice, IceBridge will also help set the stage for ICESat-2 by measuring ice the satellite will fly over. One of IceBridge’s highest priority surveys is a circular flight the DC-8 will fly around the South Pole at 88 degrees south latitude. This latitude line is where all of ICESat-2’s orbits will converge in the Southern Hemisphere. Measuring ice elevation at these locations will help researchers build a time series of data that spans more than a decade and provide a way to help verify ICESat-2’s data.

IceBridge’s Antarctic field campaign will run through late November. The IceBridge project science office is based at Goddard. The DC-8 research aircraft is based at NASA’s Armstrong Flight Research Center’s facility in Palmdale, California.

For more about Operation IceBridge, visit:

http://www.nasa.gov/icebridge

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's recent Earth science activities, visit:

http://www.nasa.gov/earthrightnow

NASA

Guillermo Gonzalo Sánchez Achutegui

ayabaca@gmail.com

ayabaca@hotmail.com

ayabaca@yahoo.com

NASA : NASA to Investigate Climate Impacts of Arctic Sea Ice Loss

Youtube Override: 

Image Credit: 

NASA's Goddard Space Flight Center/J. Beck

 

Feature Link: 

Download this video in HD formats from NASA Goddard's Scientific Visualization Studio

A new NASA field campaign will begin flights over the Arctic this summer to study the effect of sea ice retreat on Arctic climate. The Arctic Radiation IceBridge Sea and Ice Experiment (ARISE) will conduct research flights Aug. 28 through Oct. 1, covering the peak of summer sea ice melt.

ARISE is NASA's first Arctic airborne campaign designed to take simultaneous measurements of ice, clouds and the levels of incoming and outgoing radiation, the balance of which determines the degree of climate warming. The campaign team will fly aboard NASA’s C-130 aircraft from Thule Air Base in northern Greenland the first week and from Eielson Air Force Base near Fairbanks, Alaska, through the remainder of the campaign.

In recent years the Arctic has experienced increased summer sea ice loss. Scientists expect the exposure of more open water to sunlight could enhance warming in the region and cause the release of more moisture to the atmosphere. Additional moisture could affect cloud formation and the exchange of heat from Earth’s surface to space. Researchers are grappling with how these changes in the Arctic affect global climate.

NASA’s C-130 aircraft will carry scientists over the Arctic starting this month from northern Greenland and Fairbanks, Alaska.

Image Credit: 

NASA

 

"A wild card in what's happening in the Arctic is clouds and how changes in clouds, due to changing sea-ice conditions, enhance or offset warming," said Bill Smith, ARISE principal investigator at NASA's Langley Research Center in Hampton, Virginia.

ARISE was planned over the last year to take advantage of NASA’s existing capabilities for gathering data about ongoing changes in the Arctic. Satellites provided some information about clouds and the energy balance in the Arctic, but the multiple instruments flown during ARISE should provide further insight.

"The clouds and surface conditions over the Arctic as we observe them from satellites are very complex," Smith said. "We need more information to understand how to better interpret the satellite measurements, and an aircraft can help with that."

The array of instruments on ARISE should help scientists better observe how sea ice loss is affecting Arctic cloud formation and therefore the balance of incoming and outgoing radiation. Low-level clouds typically reflect more sunlight and offset warming, while higher clouds are typically less reflective and act to trap more heat in the atmosphere.

“It’s a complex business, but it depends on a lot of things we can, in fact, measure,” said Hal Maring, program manager for radiation sciences in the Earth Science Division at NASA Headquarters in Washington.

ARISE researchers will fly survey missions that target different cloud types and surface conditions, such as open water, land ice and sea ice. The missions will be timed to fly under the orbit paths of key satellite instruments, such as the Clouds and the Earth’s Radiant Energy Systems (CERES) instruments on multiple NASA satellites. Each morning, mission planners will look at satellite timings and weather forecasts to design flight plans that meet the most objectives of the campaign.

The NASA C-130, based at the Wallops Flight Facility in Virginia, will carry instruments that measure solar (incoming) and infrared (outgoing) radiation, ice surface elevation and cloud properties such as cloud particle size. This will be the first time that many of these instruments, including the mission's laser altimeter, have flown together.

The ARISE campaign is a joint effort of the Radiation Sciences, Cryospheric Sciences and Airborne Sciences programs of the Earth Science Division in NASA's Science Mission Directorate in Washington.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

To learn more about NASA's Earth science activities in 2014, visit:

http://www.nasa.gov/earthrightnow

NASA

Guillermo Gonzalo Sánchez Achutegui

ayabaca@gmail.com

ayabaca@hotmail.com

ayabaca@yahoo.com

Warm Ocean Currents Cause Majority of Ice Loss from Antarctica

Hi My Friends: AL VUELO DE UN QUINDE EL BLOG., Warm ocean currents attacking the underside of ice shelves are the dominant cause of recent ice loss from Antarctica, a new study using measurements from NASA's Ice, Cloud, and land Elevation Satellite (ICESat) revealed.

Warm Ocean Currents Cause Majority of Ice Loss from Antarctica :

WASHINGTON -- Warm ocean currents attacking the underside of ice shelves are the dominant cause of recent ice loss from Antarctica, a new study using measurements from NASA's Ice, Cloud, and land Elevation Satellite (ICESat) revealed.

An international team of scientists used a combination of satellite measurements and models to differentiate between the two known causes of melting ice shelves: warm ocean currents thawing the underbelly of the floating extensions of ice sheets and warm air melting them from above. The finding, published today in the journal Nature, brings scientists a step closer to providing reliable projections of future sea level rise.

The researchers concluded 20 of the 54 ice shelves studied are being melted by warm ocean currents. Most of these are in West Antarctica, where inland glaciers flowing down to the coast and feeding into these thinning ice shelves have accelerated, draining more ice into the sea and contributing to sea-level rise. This ocean-driven thinning is responsible for the most widespread and rapid ice losses in West Antarctica and the majority of Antarctic ice sheet loss during the period studied.

"We can lose an awful lot of ice to the sea without ever having summers warm enough to make the snow on top of the glaciers melt," said the study's lead author Hamish Pritchard of the British Antarctic Survey in Cambridge, United Kingdom. "The oceans can do all the work from below."

To map the changing thickness of almost all the floating ice shelves around Antarctica, the team used a time series of 4.5 million surface height measurements taken by a laser instrument mounted on ICESat from October 2003 to October 2008. They measured how the ice shelf height changed over time and ran computer models to discard changes in ice thickness because of natural snow accumulation and compaction. The researchers also used a tide model that eliminated height changes caused by tides raising and lowering the ice shelves.

"This study demonstrates the power of space-based, laser altimetry for understanding Earth processes," said Tom Wagner, cryosphere program scientist at NASA Headquarters in Washington." Coupled with NASA's portfolio of other ice sheet research using data from our GRACE mission, satellite radars and aircraft, we get a comprehensive view of ice sheet change that improves estimates of sea level rise."

Previous studies used satellite radar data to measure the evolution of ice shelves and glaciers, but laser measurements are more precise in detecting changes in ice shelf thickness through time. This is especially true in coastal areas. Steeper slopes at the grounding line, where floating ice shelves connect with the landmass, cause problems for lower-resolution radar altimeters.

ICESat was the first satellite specifically designed to use laser altimetry to study the Earth's polar regions. It operated from 2003 to 2009. Its successor, ICESat-2, is scheduled for launch in 2016.

"This study demonstrates the urgent need for ICESat-2 to get into space," said Jay Zwally, ICESat project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "We have limited information on the changes in polar regions caused by climate change. Nothing can look at these changes like satellite measurements do."

The new research also links the observed increase in melting that occurs on the underside of a glacier or ice shelf, called basal melt, and glacier acceleration with changes in wind patterns.

"Studies have shown Antarctic winds have changed because of changes in climate," Pritchard said. "This has affected the strength and direction of ocean currents. As a result warm water is funnelled beneath the floating ice. These studies and our new results suggest Antarctica's glaciers are responding rapidly to a changing climate."

A different picture is seen on the Antarctic Peninsula, the long stretch of land pointing towards South America. The study found thinning of the largest ice shelf on the peninsula can be explained by warm summer winds directly melting the snow on the ice shelf surfaces. The patterns of widespread ocean-driven melting and summer melting on the Antarctic Peninsula can be attributed to changing wind patterns.

The study was carried out by an international team from the British Antarctic Survey, Utrecht University in Utrecht, Netherlands, the University of California in San Diego and the non-profit research institute Earth and Space Research in Corvallis, Ore.

For more information, a visualization and related imagery, visit:
http://www.nasa.gov/topics/earth/features/currents-ice-loss.html Guillermo Gonzalo Sánchez Achutegui
ayabaca@gmail.com
ayabaca@hotmail.com
ayabaca@yahoo.com

For more information about ICESat and ICESat-2, visit:
http://icesat.gsfc.nasa.gov/