Washington DC (SPX) Sep 14, 2010
The Arctic Ocean is covered by a dynamic layer of sea ice that grows each winter and shrinks each summer, reaching its yearly minimum size each fall. While the 2010 minimum remains to be seen, NASA's Aqua satellite captured this snapshot on Sept. 3.
How does the Aqua satellite "see" sea ice? Microwaves. Everything on Earth's surface - including people - emits microwave radiation, the properties of which vary with the emitter, thereby allowing the AMSR-E microwave sensor on Aqua to map the planet.
Ice emits more microwave radiation than water, making regions of the ocean with floating ice appear much brighter than the open ocean to the AMSR-E sensor. This difference allows the satellite to capture a sea ice record year-round, through cloud cover and the months of polar night.
Continuous records are important because sea ice is dynamic. Besides melting and freezing, the ice moves with wind and currents which can cause it to split or pile up.
"The data from AMSR-E and other NASA satellites are critical for understanding the coupling between sea ice and the ocean and atmosphere," said Tom Wagner, Cryosphere program manager at NASA Headquarters in Washington.
"It's important for us to understand these connections to improve our predictive models of how the planet will change."
The Arctic sea ice is a major factor in the global climate system. The ice cools the planet by reflecting sunlight back into space. It also helps drive ocean circulation by converting the warm Pacific water that flows into the Arctic into the cold, saltier water that empties into the Atlantic.
The sea ice also fundamentally shapes the Arctic; defining the organisms that make up its ecosystem and keeping heat from the ocean from melting the frozen tundra.
In fall 2009, Arctic sea ice reached its minimum extent on about Sept. 12, and was the third lowest since satellite microwave measurements were first made in 1979. Researchers are interested in year-to-year changes, which can be highly variable, so that scientists need many years, even decades, of data to examine long-term trends.
Notably, all of the major minimums have occurred in the last decade, consistent with other NASA research, which shows January 2000 to December 2009 was the warmest decade on record.
As the sea ice nears the 2010 minimum later this month, look for images and analysis from NASA and the National Snow and Ice Data Center, in Boulder, Colo.
Share This Article With Planet Earth
NASA Earth Observatory
Earth Observation News - Suppiliers, Technology and Application
Satellites Reveal Russian Fires Worst In 14 Years
Paris, France (SPX) Sep 14, 2010
More wildfires have burned around the Russian capital this year than in the last decade and a half, according to sensors aboard ESA's observation satellites. The forest and peat bog fires ignited this summer amid an unprecedented heat wave of up to 40 degrees C. Working like thermometers in the sky, the Along Track Scanning Radiometer and the Advanced Along Track Scanning Radiometer on ESA ... read more
Sirius XM-5 Satellite Delivered To Baikonur For October Launch|
Emerging Technologies May Fuel Revolutionary Launcher
EUMETSAT Chooses Arianespace To Launch Metop-C
Falcon 1e Launch Capabilities Brought To The European Institutional Market
NASA's Next Mars Rover Rolls Over Ramps
Don't Forget Deimos
Russia to test Mars lander for 2011 flight
How Microbes Could Help Colonize Mars
Russia To Test Unmanned Lander For Mars Moon Mission
China preps next lunar space mission
Chandrayaan-2 Will Try Out New Ideas And Technologies
Data From Chandrayaan Moon Mission To Go Public
Flying To The Edge
Picture-Perfect Pluto Practice
Weighing The Planets, From Mercury To Saturn
Pounding Particles To Create Neptune's Water In The Lab
This Planet Smells Funny
Scientists looking to spot alien oceans
Deadly Tides Mean Early Exit For Hot Jupiters
Can We Spot Volcanoes On Alien Worlds
Successful Static Testing Of L 110 Liquid Core Stage Of GSLV 3
Danish rocketeers abort launch attempt
Technical glitch grounds homemade Danish rocket
ISRO To Conduct Key Test For GSLV Mk III Rocket Next Week
China's Second Lunar Probe Chang'e-2 To Reach Lunar Orbit Faster Than Chang'e-1
China Finishes Construction Of First Unmanned Space Module
China Contributes To Space-Based Information Access A Lot
China Sends Research Satellite Into Space
Avoiding An Asteroid Collision
Scientists find 'rubble pile' asteroids
Amateur Astronomers Open Potential Lab In Outer Space For Planetary Scientists
Two asteroids to pass close to Earth, but won't hit: NASA
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement|