Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NASA’s High-Flying Laser Altimeter to Check Out Summer Sea Ice and More

14.07.2014

Sea ice in summer looks dramatically different than sea ice in winter, even in the polar Arctic. Summer snowmelt, pools of water on thinning ice and exposed ocean replace vast winter expanses of white snow-covered ice – and this weekend NASA’s high-flying laser altimeter begins a campaign to investigate these features.

Icy areas look different from a satellite’s perspective as well. When NASA launches the Ice, Cloud and land Elevation Satellite-2, or ICESat-2, in 2017, it will measure Earth’s elevation by sending out pulses of green laser light and timing how long it takes individual photons to bounce off Earth’s surface and return. The number and patterns of photons that come back depend on the type of ice they bounce off – whether it’s smooth or rough, watery or snow-covered. 


This summer, the Multiple Altimeter Beam Experimental Lidar, or MABEL, will fly above Alaska and the Arctic Ocean on one of NASA’s ER-2 high-altitude aircraft.

Image Credit: NASA/Carla Thomas

To get a preview of what summertime will look like to ICESat-2, NASA scientists, engineers and pilots have travelled to Fairbanks, Alaska, to fly an airborne test bed instrument called the Multiple Altimeter Beam Experimental Lidar, or MABEL. MABEL collects data in the same way that ICESat-2’s instrument will – with lasers and photon-detectors. So the data from the Alaskan campaign will allow researchers to develop computer programs, or algorithms, to analyze the information from ICESat-2.

“We need to give scientists data to enable them to develop algorithms that work during summer,” said Thorsten Markus, ICESat-2’s project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “All the algorithms need to be tested and in place by the time of launch. And one thing that was missing was ICESat-2-like data on the summer conditions.”

Between July 12 and August 1, MABEL will fly aboard NASA’s high-altitude ER-2 aircraft as the Arctic sea ice and glaciers are melting. In its half-dozen flights, the instrument will take measurements of the sea ice and Alaska’s southern glaciers, as well as forests, lakes, open ocean, the atmosphere and more, sending data back to researchers on the ground.

A key element of the campaign, however, is to fly over melt ponds – areas where snow has melted, pooling up in low spots of the sea ice or glaciers – and bare ice with no snow coverage to find out how to identify and study these features with ICESat-2-like data.

Scientists have many questions about melt ponds, and their impact on the extent of summer ice melt. Dark water absorbs much more heat from the sun than bright, reflective ice and snow, so when a pool of liquid water forms on top of ice, it changes the heat balance. The water warms up in the summer sun, and can speed up melting of the surrounding ice, possibly influencing the Arctic Ocean’s sea ice minimum extent.

“The melt pond coverage may be an indicator of the ice coverage at the end of the summer,” said Ron Kwok, a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. “But we don’t have a lot of information about melt pond coverage over the Arctic.”

Although scientists know the ponds are present, and cover a lot of area, they don’t know how the number, size and depth vary from year to year, and region to region, said Kwok, also a member of the ICESat-2 Science Definition Team who is developing sea ice algorithms.

Melt ponds can also tell researchers about the sea ice itself, Kwok said. Deeper, smaller ponds can form on the bumpy and ridged older ice, which has withstood multiple years in the Arctic Ocean. Newer ice – ice that formed the winter before – hasn’t had the time to build up ridges, and so would be flat and covered with large shallow ponds.

“In the summer, we can tell whether it’s first year ice or older, based roughly on the shape and size of the melt ponds,” Kwok said.

The MABEL flights will allow researchers to determine what those ponds and melting snow will look like from ICESat-2, and how to best analyze the returning photons. The ponds could be tricky to study, he said, since some photons might reflect off the surface, while others could make it through the water to bounce off the bottom of the pond.

“We have to design the algorithms to adapt to what we’re learning this summer,” Kwok said. “We don’t have any preconceived notions as to what we might see, and that’s why it’s so important to fly MABEL.”

The flight plans for the ER-2 carrying MABEL involve a route that would take it north, possibly over the North Pole, to look at a variety of sea ice conditions, as well as some ice fields north of Fairbanks, said Bill Cook, MABEL’s lead scientist. The aircraft will also fly above forests, along some of the same paths of another NASA campaign that is flying Goddard's LiDAR, Hyperspectral and Thermal Imager, or G-LiHT, just above the treetops. Researchers will be able to then compare the data from MABEL and G-LiHT, Cook noted.

With 48 hours of flying time available, he said, the first priority are the flights north toward the pole to see how different the summer ice looks to MABEL. 

Follow NASA campaigns blogging from Alaska this summer at:

http://earthobservatory.nasa.gov/blogs/fromthefield/

For more information on ICESat-2, visit:

http://icesat.gsfc.nasa.gov/icesat2/

For more information on G-LiHT, visit:

http://gliht.gsfc.nasa.gov/ 

Kate Ramsayer

NASA’s Goddard Space Flight Center

Kate Ramsayer | Eurek Alert!
Further information:
http://www.nasa.gov/content/goddard/nasa-s-high-flying-laser-altimeter-to-check-out-summer-sea-ice-and-more/

Further reports about: Altimeter Arctic Flight High-Flying ICESat-2 NASA Space conditions glaciers heat photons

More articles from Earth Sciences:

nachricht Clouds and climate in the pre-industrial age
30.05.2016 | Goethe-Universität Frankfurt am Main

nachricht Researchers find higher than expected carbon emissions from inland waterways
25.05.2016 | Washington State University

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Attosecond camera for nanostructures

Physicists of the Laboratory for Attosecond Physics at the Max Planck Institute of Quantum Optics and the Ludwig-Maximilians-Universität Munich in collaboration with scientists from the Friedrich-Alexander-Universität Erlangen-Nürnberg have observed a light-matter phenomenon in nano-optics, which lasts only attoseconds.

The interaction between light and matter is of key importance in nature, the most prominent example being photosynthesis. Light-matter interactions have also...

Im Focus: Worldwide Success of Tyrolean Wastewater Treatment Technology

A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.

The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

Better combustion for power generation

31.05.2016 | Power and Electrical Engineering

Stick insects produce bacterial enzymes themselves

31.05.2016 | Life Sciences

In a New Method for Searching Image Databases, a Hand-drawn Sketch Is all it Takes

31.05.2016 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>