Antarctic Sea Ice Reaches New Record Maximum - Video

This year, Antarctic sea ice reached a record maximum extent while the Arctic reached a minimum extent in the ten lowest since satellite records began. Why are these trends going in opposite directions?

Image Credit: NASA Goddard Space Flight Center/Joy Ng

Sea ice surrounding Antarctica reached a new record high extent this year, covering more of the southern oceans than it has since scientists began a long-term satellite record to map sea ice extent in the late 1970s.

The upward trend in the Antarctic, however, is only about a third of the magnitude of the rapid loss of sea ice in the Arctic Ocean.

The new Antarctic sea ice record reflects the diversity and complexity of Earth’s environments, said NASA researchers.

Claire Parkinson, a senior scientist at NASA’s Goddard Space Flight Center, has referred to changes in sea ice coverage as a microcosm of global climate change.

Just as the temperatures in some regions of the planet are colder than average, even in our warming world, Antarctic sea ice has been increasing and bucking the overall trend of ice loss.

“The planet as a whole is doing what was expected in terms of warming. Sea ice as a whole is decreasing as expected, but just like with global warming, not every location with sea ice will have a downward trend in ice extent,” Parkinson said.

Since the late 1970s, the Arctic has lost an average of 20,800 square miles (53,900 square kilometers) of ice a year; the Antarctic has gained an average of 7,300 square miles (18,900 sq km).

On Sept. 19 this year, for the first time ever since 1979, Antarctic sea ice extent exceeded 7.72 million square miles (20 million square kilometers), according to the National Snow and Ice Data Center. The ice extent stayed above this benchmark extent for several days.

The average maximum extent between 1981 and 2010 was 7.23 million square miles (18.72 million square kilometers).

The single-day maximum extent this year was reached on Sept. 20, according to NSIDC data, when the sea ice covered  7.78 million square miles (20.14 million square kilometers).

This year's five-day average maximum was reached on Sept. 22, when sea ice covered 7.76 million square miles (20.11 million square kilometers), according to NSIDC.

On Sept. 19, 2014, the five-day average of Antarctic sea ice extent exceeded 20 million square kilometers for the first time since 1979, according to the National Snow and Ice Data Center (NSIDC). 

The red line shows the average maximum extent from 1979-2014.

Image Credit: NASA's Scientific Visualization Studio/Cindy Starr

A warming climate changes weather patterns, said Walt Meier, a research scientist at Goddard.

Sometimes those weather patterns will bring cooler air to some areas, and in the Antarctic, where sea ice circles the continent and covers such a large area, it doesn’t take that much additional ice extent to set a new record.

“Part of it is just the geography and geometry. With no northern barrier around the whole perimeter of the ice, the ice can easily expand if conditions are favorable,” he said.

Researchers are investigating a number of other possible explanations as well. One clue, Parkinson said, could be found around the Antarctic Peninsula, a finger of land stretching up toward South America.

There, the temperatures are warming, and in the Bellingshausen Sea just to the west of the peninsula the sea ice is shrinking.

Beyond the Bellingshausen Sea and past the Amundsen Sea, lies the Ross Sea, where much of the sea ice growth is occurring.

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NASA IceBridge: Snow has thinned on Arctic sea ice

The probe, shaped like a ski pole, includes a basket that stays on top of the snow while the tip of the probe plunges down to the sea ice below. 

Credit: Chris Linder / Univ. of Washington.

From research stations drifting on ice floes to high-tech aircraft radar, scientists have been tracking the depth of snow that accumulates on Arctic sea ice for almost a century.

Now that people are more concerned than ever about what is happening at the poles, research led by the Earth Science dept of University of Washington and NASA IceBridge confirms that snow has thinned significantly in the Arctic, particularly on sea ice in western waters near Alaska.

A new study, accepted for publication in the Journal of Geophysical Research: Oceans, a publication of the American Geophysical Union, combines data collected by ice buoys and NASA aircraft with historic data from ice floes staffed by Soviet scientists from the late 1950s through the early 1990s to track changes over decades.

Historically, Soviets on drifting sea ice used meter sticks and handwritten logs to record snow depth. Today, researchers on the ground use an automated probe similar to a ski pole to verify the accuracy of airborne measurements.

"When you stab it into the ground, the basket move up, and it records the distance between the magnet and the end of the probe," said first author Melinda Webster, a UW graduate student in oceanography.

"You can take a lot of measurements very quickly. It's a pretty big difference from the Soviet field stations."

Webster verified the accuracy of airborne data taken during a March 15, 2012 NASA IceBridge flight over the sea ice near Barrow, Alaska.

The following day Webster followed the same track in minus 30-degree temperatures while stabbing through the snow every two to three steps.

UW graduate student Melinda Webster uses a probe to measure snow depth and verify NASA airborne data. 

She is walking on sea ice near Barrow, Alaska, in March 2012. 

Her backpack holds electronics that power the probe and record the data. 

Credit: Chris Linder / Univ. of Washington

The authors compared data from NASA airborne surveys, collected between 2009 and 2013, with U.S. Army Corps of Engineers buoys frozen into the sea ice, and earlier data from Soviet drifting ice stations in 1937 and from 1954 through 1991.

Results showed that snowpack has thinned from 14 inches to 9 inches (35 cm to 22 cm) in the western Arctic, and from 13 inches to 6 inches (33 cm to 14.5 cm) in the Beaufort and Chukchi seas, west and north of Alaska.

That's a decline in the western Arctic of about a third, and snowpack in the Beaufort and Chukchi seas less than half as thick in spring in recent years compared to the average Soviet-era records for that time of year.

"Knowing exactly the error between the airborne and the ground measurements, we're able to say with confidence, Yes, the snow is decreasing in the Beaufort and Chukchi seas," said co-author Ignatius Rigor, an oceanographer at the UW's Applied Physics Laboratory.

NASA IceBridge: 2014 Arctic campaign starts with two surveys of sea ice north of Greenland

This is a moon shot over northeast Greenland while descending into the survey area north of the Fram Strait. 

Credit: NASA/Michael Studinger

NASA's Operation IceBridge started the 2014 Arctic campaign with two surveys of sea ice north of Greenland.

The two flights follow similar surveys flow in previous years and continue the mission's goals of collecting data on changing sea ice in the Arctic.

Following the Mar. 10 transit flight from NASA's Wallops Flight Facility in Virginia to Thule Air Base, Greenland, the IceBridge team continued preparing for the weeks of work ahead.

On Mar. 11 the team unpacked cargo and set up ground-based GPS stations that are used to ensure IceBridge's instruments are accurate.

The next morning, Mar. 12, researchers, pilots and flight crew boarded the P-3 and took off for the first science flight of the campaign, a mission called Sea Ice – Nansen Gap.


This survey was a variation of flights over the Fram Strait flown in previous years that sampled ice farther north and east than in the past.

Researchers used the mission's laser and radar instruments to collect data on sea ice elevation and snow depth and collected ice thickness and elevation data while flying high over the Greenland Ice Sheet.

While studying the ice below, the team was treated to interesting sights in the sky during this flight.

Shortly after takeoff the moon made an appearance on the horizon, giving those aboard the aircraft a good photo opportunity.

In addition the team got to see the sun setting twice – once on the eastern end of the survey line and again when returning to Thule Air Base.

At this time of year days are short at high latitudes, making this sort of thing common.

SECOND SURVEY
On Mar. 13, the IceBridge team carried out their second survey of the campaign, a flight plan known as Sea Ice – Zigzag East.

On this flight the P-3 headed north-northeast out of Thule, roughly following the coast of Greenland along the Nares Strait—a narrow body of water separating Greenland and Canada's Ellesmere Island.

Then researchers headed along an alternating north and south pattern to measure how sea ice thickness changes closer to the North Pole, something known as ice gradient.

On this flight, researchers collected data on thick, multi-year ice near the coast and thinner ice farther north.

With two successful surveys and nearly three weeks left before the mission moves south to Kangerlussuaq, IceBridge is off to a successful start.

Over the next several days the mission plans to collect even more sea ice data, including a cross-basin survey of the Arctic Ocean and several flights based out of Fairbanks, Alaska, over the Beaufort and Chukchi seas.

ESA Cryosat: Arctic sea ice volume increased

Measurements from ESA’s CryoSat satellite show that the volume of Arctic sea ice has significantly increased this autumn.

The volume of ice measured this autumn is about 50% higher compared to last year.

In October 2013, CryoSat measured about 9000 cubic km of sea ice – a notable increase compared to 6000 cubic km in October 2012.

Over the last few decades, satellites have shown a downward trend in the area of Arctic Ocean covered by ice.

However, the actual volume of sea ice has proven difficult to determine because it moves around and so its thickness can change.

CryoSat was designed to measure sea-ice thickness across the entire Arctic Ocean, and has allowed scientists, for the first time, to monitor the overall change in volume accurately.

About 90% of the increase is due to growth of multiyear ice – which survives through more than one summer without melting – with only 10% growth of first year ice.

Thick, multiyear ice indicates healthy Arctic sea-ice cover.

This year’s multiyear ice is now on average about 20%, or around 30 cm, thicker than last year.

NASA AQUA MODIS Image: Totten Glazier melt rate linked to Sea Ice conditions

This image shows the Totten Glacier ice shelf in East Antarctica (the wrinkled white area at top left) on Sept. 25, 2013. 

Two large open-water polynyas appear on the sea ice below and to the right of the shelf, as well as several smaller ones. 

The open-water areas are bright black. 

The stippled diagonal line from lower left to upper right is the outer edge of the sea ice, with cloud cover to the right of that line. 

The image is from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Aqua satellite. 

Credit: NASA.

A new NASA-led study has discovered an intriguing link between sea ice conditions and the melting rate of Totten Glacier, the glacier in East Antarctica that discharges the most ice into the ocean.

The discovery, involving cold, extra salty water - brine - that forms within openings in sea ice, adds to our understanding of how ice sheets interact with the ocean, and may improve our ability to forecast and prepare for future sea level rise.

"I was curious why Totten was changing so fast when the glacier just next to it wasn't changing much," said Ala Khazender of NASA's Jet Propulsion Laboratory, Pasadena, Calif., lead author of the new study, published online Dec. 5 in the journal Nature Communications.

Combining satellite observations with ocean numerical modeling, Khazender and his colleagues developed a hypothesis that reductions in the volume of brine would increase Totten's thinning and melting.

Additional research supported that hypothesis.

Ice loss seen in Antarctica is generally attributed to the well-documented rise in temperature of the surrounding ocean, but scientists are still puzzling out the mechanisms behind the regional variations that they are observing.

The new study highlights the key role of processes occurring on small geographic scales in determining how global climate change can affect the stability of ice sheets.

Satellite observations from NASA's ICESat-1, which measures how much ice surfaces are rising or falling over time, revealed that Totten Glacier was thinning rapidly.

It currently discharges enough ice into the surrounding ocean to fill Lake Erie in just over a week.

The nearby Moscow University Glacier and its floating ice shelf were showing little change. Why the difference?

"We were convinced that the answer must be in the ocean," Khazender said.

The ocean around Antarctica is warmer than both the continent's icy surface and the polar air. Ice shelves (the floating front edges of glaciers that extend tens to hundreds of miles offshore) melt more because of contact with ocean water below them than they do because of sunlight.

Melting at the undersides of ice shelves is part of Antarctica's natural water cycle, but when glaciers start melting unusually quickly, it's a sign that something is off balance.

Khazender and his team of colleagues from JPL; UCLA; the University of California, Irvine; and Utrecht University in the Netherlands combined ICESat remote sensing observations from 2003 to 2008 with ocean numerical computer models to seek insights into the interaction between the ice shelves and their ocean basin.

More information: For more information on ICESat, visit: icesat.gsfc.nasa.gov/ .For more information on the ECCO2 ocean modeling and data synthesis project, visit: ecco2.jpl.nasa.gov/

NASA MODIS Image: Sea Ice Off Eastern Greenland

The MODIS instrument on NASA's Aqua satellite captured this visible image of Sea Ice off eastern Greenland on October 16, 2012.

Image Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team

Terra (formerly known as EOS/AM-1) is a joint Earth observing mission within NASA's ESE (Earth Science Enterprise) program between the United States, Japan, and Canada. 

The US provided the spacecraft, the launch, and three instruments developed by NASA (CERES, MISR, MODIS). 

Japan provided ASTER and Canada MOPITT. 

The Terra spacecraft is considered the flagship of NASA's EOS (Earth Observing Satellite) program. In February 1999, the EOS/AM-1 satellite was renamed by NASA to “Terra”.

NASA: NOAA Arctic Cyclone Breaks Up Sea Ice

The storm cut off a large section of sea ice north of the Chukchi Sea and pushed it south to warmer waters that made it melt entirely. It also broke vast extensions of ice into smaller pieces more likely to melt.

NASA has released the following animation which shows how the winds of a large Arctic cyclone broke up the thinning sea ice cover of the Arctic Ocean in early August 2012.

According to NASA the storm likely contributed to the ice cap's shrinking to the smallest recorded extent in the past three decades.

The frozen cap of the Arctic Ocean likely reached its annual summertime minimum extent and broke a new record low on Sept. 16, the National Snow and Ice Data Center (NSIDC) at the University of Colorado in Boulder has reported.

Analysis of satellite data by NASA and the NASA-supported NSIDC showed that the sea ice extent shrunk to 1.32 million square miles (3.41 million square kilometers), or 293,000 square miles less than the previous lowest extent in the satellite record, set in mid-September, 2007.

Arctic Cyclone Breaks Up Sea Ice.

"Climate models have predicted a retreat of the Arctic sea ice; but the actual retreat has proven to be much more rapid than the predictions," said Claire Parkinson, a climate scientist at NASA Goddard Space Flight Center, Greenbelt, Md.

"There continues to be considerable inter-annual variability in the sea ice cover, but the long-term retreat is quite apparent."

This year, the cyclone formed off the coast of Alaska and moved on Aug. 5 to the center of the Arctic Ocean, where it churned the weakened ice cover for several days.

"The storm definitely seems to have played a role in this year's unusually large retreat of the ice," Parkinson said.

"But that exact same storm, had it occurred decades ago when the ice was thicker and more extensive, likely wouldn't have had as prominent an impact, because the ice wasn't as vulnerable then as it is now."

Sea ice data courtesy of the Defense Meteorological Satellite Program (DMSP). Wind data courtesy of the National Centers for Environmental Prediction (NCEP).

Visualization credit: Scientific Visualization Studio/NASA Goddard Space Flight Cente

NASA AQUA satellite: Arctic Sea Ice Minimum for 2010

On September 19, Arctic sea ice reached its 2010 minimum, at 4.60 million square kilometers (1.78 million square miles). The National Snow and Ice Data Center (NSIDC) reported that 2010 Arctic sea ice extent was the third-lowest on the satellite record.

The record low, was set in 2007, was 4.13 million square kilometers, or 1.59 million square miles. The 2010 minimum was part of a larger pattern of overall Arctic sea ice decline dating back to at least the early 1970s.

The top image, made from sea ice observations collected by the Advanced Microwave Scanning Radiometer (AMSR-E) Instrument on NASA’s Aqua satellite, shows sea ice extent on September 19, 2010.

Ice-covered areas range in color from white (highest concentration) to light blue (lowest concentration). Ocean water is dark blue, and landmasses are dark gray.

The yellow outline is the median minimum sea ice extent for 1979–2000; that is, areas that were at least 15 percent ice-covered in at least half the years between 1979 and 2000. Compared to the long-term average, sea ice concentration north of Alaska and eastern Siberia was especially low in 2010.

Arctic sea ice behaviour was unusual in 2010 in that the sea ice appeared to reach its minimum extent on September 10 and began growing again.

Acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite, the middle and bottom images capture some of that ice growth, occurring in the East Siberian Sea.

The middle image is from September 12, and the bottom image is from September 14. New, thin ice appears in the bottom image as rippled sheets, barely lighter than the underlying ocean water.

This is probably nilas—thin sheets of ice with an oily or greasy appearance. (See the Earth Observatory Sea Ice feature article to learn more about different types of sea ice.)

After a few days of growth, sea ice declined again until September 19. According to NSIDC scientist Walt Meier, the renewed melting late in the season suggested that sea ice cover was thin and loosely packed.

Those conditions make sea ice susceptible not only to melting, but also to disintegration by wind. In early September, NSIDC described large areas of rotten ice in an advanced state of disintegration.

The minimum sea ice extent in 2010 fits into a long-term pattern of decline, especially in multi-year ice, which persists through the summer melt season and into another winter. Multi-year ice may last for several years, eventually growing up to 4 meters (13 feet) thick.

First-year ice is thinner, saltier, and more vulnerable to melt. NSIDC stated that the 2010 season showed an increase in second- and third-year ice—which might eventually thicken—but the oldest and thickest ice had mostly disappeared from the Arctic.

“A band of thick ice is likely to persist along northern Greenland and northern Canada for some time,” said Ted Scambos, lead scientist at NSIDC. “But in the next 10 to 15 years, there could be substantial open water in the Arctic in the summertime.”

NASA - A Snapshot of Sea Ice

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.

ESA ENVISAT MERIS Image: Sea Ice of Okhotsk

This Envisat image captures sea ice in the Sea of Okhotsk off the northeastern coast of Russia’s Sakhalin Island (top left) and the northern tip of Japan’s Hokkaido Island (bottom left).

Sea ice began forming in the northern area over the Sea of Okhotsk in November 2009. Since then, it extended down to about 30 km off the northern coast of Hokkaido and has likely reached its maximum.

Sakhalin is separated from the east coast of Russia by the narrow Strait of Tartary and from the northern tip of Japan by the Strait of La Pérouse, which appears to be ice-free.

Sitting astride an active seismic zone, Sakhalin is prone to earthquakes that can trigger mudslides. The formal penal colony is covered in ice during the winter months, and its surrounding cool, fertile waters support enormous fisheries. But that’s not all; an estimated 45 billion barrels of oil equivalent are believed to lie beneath the icy seas off its shores.

Hokkaido is the northernmost and second largest island of Japan’s four main islands. The three islands visible northeast of Hokkaido belong to the Kuril Island chain, which comprises 22 main islands and some 30 smaller islets.

Stretching for 1250 km northwards from Hokkaido to the southern tip of Russia's Kamchatka Peninsula (not visible), the Kuril Islands form a boundary between the Sea of Okhotsk and the Pacific Ocean (bottom right).

This image was acquired by Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument on 9 March 2010, working in Full Resolution mode to provide a spatial resolution of 300 m.

Baffin Island: Seasonal Ice Melt

In the depths of winter, ice hugs the coastline of Canada’s Baffin Island. Summertime sunlight, however, dramatically melts the ice away from the coastline.

Seasonal sea ice retreat was well underway when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color (photo-like) image on July 11, 2009.

Clouds often hover over the Arctic during the Northern Hemisphere summer, making cloud-free images such as this one relatively rare.

Although a few wispy clouds appear in the upper right and lower left corners of this image, the delicate swirls of white running along the eastern edge of Baffin Island are sea ice.

Eddies along Baffin Island’s coast have fashioned the ice into interlocking swirls, especially near Cumberland Sound. Farther north, a long band of ice holds fast to the shore east of Barnes Icecap.

Although less inclined to move with the currents, this ice also shows signs of weakening, as its edges splinter, and pieces float away.

The sea ice retreat captured in this image appears typical of seasonal melt. Since the turn of the twenty-first century, however, Arctic sea ice extent has declined sharply, experiencing a series of low summertime extents and poor wintertime recoveries.

Arctic sea ice extent set a record low in September 2007. As of July 22, 2009, the National Snow and Ice Data Center reported that, in the first half of July 2009, sea ice declined faster than it did in 2008, but not as fast as it did in 2007.