Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laser precision: NASA flights, satellite align over sea ice

04.10.2019

The skies were clear, the winds were low, and the lasers aligned. In April, instruments aboard NASA's Operation IceBridge airborne campaign and the Ice, Cloud and Land Elevation Satellite-2 succeeded in measuring the same Arctic sea ice at the same time, a tricky feat given the shifting sea ice. Scientists have now analyzed airborne and spaceborne height measurements, and found that the two datasets match almost exactly, demonstrating how precisely ICESat-2 can measure the heights of the sea ice's bumpy, cracked surface.

"If you look at the height profiles from ICESat-2 and IceBridge, you can tell that they're almost the same," said Ron Kwok, a sea ice scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, and lead author of the new study. "It's a good pitch for the quality of the ICESat-2 data."


This is a refrozen sea ice lead in the Arctic Ocean.

Credit: NASA/Jeremy Harbeck

ICESat-2 uses its laser instrument to measure the heights of Earth's surface, focusing on the glaciers, ice sheets and sea ice in the planet's polar regions. When it launched on Sept. 15, 2018, scientists were poised to take measurements from planes and on the ground to check against the satellite's data, helping to and ensure the accuracy of the measurements from orbit.

The Operation IceBridge team has been flying campaigns over Greenland and Antarctica for a decade, and once ICESat-2 was in orbit they adjusted several missions to fly along the same path as the satellite. When they flew over ice sheets it was relatively straightforward, since the masses of ice don't gain or lose much height over a day or two, or even a week or two.

Sea ice, however, is pushed around by winds and ocean currents. If IceBridge flew along an ICESat-2 orbit track an hour after the satellite passed, it could be measuring completely different ice. So IceBridge mission scientist John Sonntag had to calculate where and when ICESat-2 was going to be over a specific spot in the Arctic ocean, and how to navigate the plane to be there at the exact same time - preferably with low winds, and definitely with no clouds to block ICESat-2's view.

"He was able to nail it," Kwok said. "He was able to get to that part of the Arctic so there's almost zero time lag between ICESat-2 and the airplane."

When Kwok and his colleagues used computer programs to line up the two datasets, they saw the same ridges, bumpy surface, and open water in both elevation profiles. With four flights worth of data comparisons, over more than 600 miles (1,000 kilometers), the two sets of height measurements closely match each other: Researchers would call an exact match 1.0, and these were correlated to more than 0.95.

Sea ice height profiles from ICESat-2 can tell scientists whether the ice is a newly formed, smooth surface or an older, rougher section. The key measurement from ICESat-2, however, is how high the ice surface is above the open water, called freeboard. If scientists know that number, they can calculate the thickness - which isn't directly measured from satellite data. When Kwok and his colleagues compared freeboard measurements from ICESat-2 and Operation IceBridge's Airborne Topographic Mapper instrument for the April flights, they were within 0.8 to 1.6 inches (2 to 4 centimeters) of each other.

With additional flights over land and sea ice in both Greenland and Antarctica this fall, Operation IceBridge is continuing to help assess ICESat-2 data, along with other efforts including the third year of an Antarctic ground traverse along a section of the 88 degree South line of latitude.

For more information, visit: nasa.gov/icesat-2 or icesat-2.gsfc.nasa.gov

Kate Ramsayer | EurekAlert!
Further information:
https://www.nasa.gov/feature/goddard/2019/laser-precision-nasa-flights-satellite-align-over-sea-ice

Further reports about: Arctic Goddard Space Flight Center ICESat-2 IceBridge Laser NASA ice sheets sea ice

More articles from Earth Sciences:

nachricht "Airlift" facility: TU Freiberg tests new mining technology in research and training mine
22.10.2019 | Technische Universität Bergakademie Freiberg

nachricht Atmospheric pressure impacts greenhouse gas emissions from leaky oil and gas wells
21.10.2019 | University of British Columbia

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A cavity leads to a strong interaction between light and matter

Researchers have succeeded in creating an efficient quantum-mechanical light-matter interface using a microscopic cavity. Within this cavity, a single photon is emitted and absorbed up to 10 times by an artificial atom. This opens up new prospects for quantum technology, report physicists at the University of Basel and Ruhr-University Bochum in the journal Nature.

Quantum physics describes photons as light particles. Achieving an interaction between a single photon and a single atom is a huge challenge due to the tiny...

Im Focus: Solving the mystery of quantum light in thin layers

A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)

It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...

Im Focus: An ultrafast glimpse of the photochemistry of the atmosphere

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...

Im Focus: Shaping nanoparticles for improved quantum information technology

Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.

Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

New deep-water coral discovered

22.10.2019 | Life Sciences

DNA-reeling bacteria yield new insight on how superbugs acquire drug-resistance

22.10.2019 | Life Sciences

Heat Pumps with Climate-Friendly Refrigerant Developed for Indoor Installation

22.10.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>