Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Scientists use satellite to ’pond-er’ melted Arctic ice


NASA researchers and other scientists used a satellite combined with aircraft video to create a new technique for detecting ponds of water on top of Arctic sea ice. Until now, it was not possible to accurately monitor these ponds on ice from space.

Water that forms on sea ice during the summer, called a melt pond, absorbs the Sun’s energy rather than reflecting it back to space the way ice does. The balance between reflected and absorbed energy has a large effect on Arctic and global climate. When more ponds of water form on the Arctic sea ice cover in early summer, more heat is absorbed, causing the Arctic’s sea ice cover to melt faster during the summer. Knowledge of when and where these melt ponds form will help scientists calculate the balance of energy in the Arctic and improve their knowledge and projections of climate both regionally and globally.

By using detailed aircraft video of Arctic surfaces and comparing those with coarser satellite imagery, the researchers were able to recognize rough features in the satellite data that corresponded to ponds on ice, ocean water, and un-melted sea ice. Now, they are able to use a satellite to monitor sea ice, without the aid of the aircraft video. Satellites offer the advantages of frequent regular flyovers that cover vast areas all at once.

"Our new technique offers the possibility of determining when and mapping where these melt ponds form and would greatly aid our understanding of the Arctic heat balance," said co-author Donald Cavalieri, a senior research scientist at NASA’s Goddard Space Flight Center (GSFC), Greenbelt, Md. An article describing the new technique appeared in a recent issue of the journal, Remote Sensing of Environment.

During spring and summer, these melt ponds cause existing sea ice to melt faster and greatly reduce the ice’s ability to reflect sunlight. This can create a positive feedback, where an increasing number of melt ponds absorbs more heat and causes sea ice cover to melt even faster.

During the warmer months, melt ponds can cover up to 50 percent of the Arctic sea ice area. There may be a relationship between the fraction of melt ponds and the amount of sea ice cover at summer’s end. Researchers know from satellite records covering the last 30-years that the Arctic sea ice cover at summer’s end has been decreasing rapidly. This new technique may help them determine whether there has also been an increase in the number of melt ponds over this period.

This new technique to detect melt pond coverage uses NASA’s Enhanced Thematic Mapper Plus (ETM+) instrument on the Landsat 7 satellite, developed with the aid of much higher resolution video imagery from a NASA supported aircraft experiment during the summer of 2000.

"This result is an excellent example of how the coordinated use of satellites and research aircraft are used to develop new techniques for observing the Earth," Cavalieri added.

By using video footage from an aircraft flight at an altitude of almost one and a half kilometers, the researchers were able to compare that higher resolution footage with Landsat 7 images passing over the same path above Baffin Bay in the Arctic on the same day. They then compared the Landsat imagery with the aircraft video.

While Landsat 7 shows less detail, it covers vast areas all at once. The aircraft video, on the other hand, allows researchers to view a 1.5 meter area in detail.

By classifying 13 high resolution images from the aircraft into areas of ocean, ice with ponds, and pond-free ice and then comparing these areas with the different wavelength bands of Landsat, the researchers were able to develop a new method to calculate the extent of open water, melt ponds, and sea ice over large areas using Landsat data by itself.

"Previously there were no systematic measurements of melt ponds, but this technique with the Landsat creates the possibility of determining when and where these melt ponds form," Cavalieri said. "It helps us understand the heat balance, which ties into the global climate system."

Lead author Thorsten Markus, who is currently conducting research at sea, is also a scientist at NASA GSFC. Other co-authors include Mark Tschudi, National Center for Atmospheric Research, Boulder, Colo., and Alvaro Ivanoff, Science Systems and Applications, Inc., Lanham, Md.

The study was funded by NASA. NASA’s Earth Science Enterprise is dedicated to understanding the Earth as an integrated system and applying Earth System Science to improve prediction of climate, weather, and natural hazards using the unique vantage point of space.

Krishna Ramanujan | GSFC

More articles from Earth Sciences:

nachricht Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union

nachricht UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>