Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Satellites Continue to See Decline In Arctic Sea Ice In 2005

30.09.2005


Researchers from NASA, the National Snow and Ice Data Center and others using satellite data have detected a significant loss in Arctic sea ice this year.



On Sept. 21, 2005, sea ice extent dropped to 2.05 million sq. miles, the lowest extent yet recorded in the satellite record. Incorporating the 2005 minimum using satellite data going back to 1978, with a projection for ice growth in the last few days of this September, brings the estimated decline in Arctic sea ice to 8.5 percent per decade over the 27 year satellite record.

Scientists involved in this research are from NASA’s Goddard Space Flight Center, Greenbelt, Md., NASA’s Jet Propulsion Laboratory, Pasadena, Calif., the National Snow and Ice Data Center at the University of Colorado, Boulder, and the University of Washington, Seattle.


Satellites have made continual observations of Arctic sea ice extent since 1978, recording a general decline throughout that period. Since 2002, satellite records have revealed early onsets of springtime melting in the areas north of Alaska and Siberia. In addition, the 2004-2005 winter season showed a smaller recovery of sea ice extent than any previous winter in the satellite record and the earliest onset of melt throughout the Arctic.

Arctic sea ice typically reaches its minimum in September, at the end of the summer melt season. The last four Septembers (2002-2005) have seen sea ice extents 20 percent below the mean September sea ice extent for 1979-2000.

Perennial ice cover is ice that survives the summer melt, consisting mainly of thick multiyear ice floes that are the mainstay of the Arctic sea ice cover. "Since 1979, by using passive microwave satellite data, we’ve seen that the area of Arctic perennial sea ice cover has been declining at 9.8 percent per decade," said Joey Comiso, senior scientist at Goddard.

For the perennial ice to recover, sustained cooling is needed, especially during the summer period. This has not been the case over the past 20 years, as the satellite data show a warming trend in the Arctic, and it is not expected to be the case in the future, as climate models project continued Arctic warming. If ice were to grow back in these areas, the new ice would likely be thinner and more susceptible to future melt than the thick perennial ice that it replaces.

Scientists are working to understand the extent to which these decreases in sea ice are due to naturally occurring climate variability or longer-term human influenced climate changes.

Scientists believe that the Arctic Oscillation, a major atmospheric circulation pattern that can push sea ice out of the Arctic, may have contributed to the reduction of sea ice in the mid-1990s by making the sea ice more vulnerable to summertime melt.

Sea ice decline could also affect future temperatures in the region. Ice reflects much of the sun’s radiation back into space. As sea ice melts, more exposed ocean water reduces the amount of energy reflected away from the Earth. "Feedbacks in the system are starting to take hold," says the National Snow and Ice Data Center’s lead scientist Ted Scambos.

Claire Parkinson, senior scientist at Goddard, cautions against thinking that Arctic sea ice is gone for good, especially with such limited data. "The reduced sea ice coverage will lead to more wintertime heat loss from the ocean to the atmosphere and perhaps therefore to colder water temperatures and further ice growth," said Parkinson.

There are many factors beyond warmer temperatures that drive changes in the Arctic. A longer data record, combined with observations from additional environmental parameters now available from NASA satellites, will help scientists better understand the changes they are now seeing.

The study used data from the Defense Meteorological Satellite Program Special Sensor/ Microwave Imager and data from NASA’s Scanning Multi-channel Microwave Radiometer (SMMR) on the NIMBUS-7 satellite.

Rob Gutro | EurekAlert!
Further information:
http://www.nasa.gov/centers/goddard/news/topstory/2005/arcticice_decline.html
http://www.nasa.gov

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>