Opposite Behaviors? Arctic Sea Ice Shrinks, Antarctic Grows
September 2012 witnessed two opposite records concerning sea ice. Two weeks after the Arctic Ocean’s ice cap experienced an all-time summertime low for the satellite era (left), Antarctic sea ice reached a record winter maximum extent (right). But sea ice in the Arctic has melted at a much faster rate than it has expanded in the Southern Ocean, as can be seen in this image by comparing the 2012 sea ice levels with the yellow outline, which in the Arctic image represents average sea ice minimum extent from 1979 through 2010 and in the Antarctic image shows the median sea ice extent in September from 1979 to 2000. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio and NASA Earth Observatory/ Jesse Allen
The steady and dramatic decline in the sea ice cover of the Arctic Ocean over the last three decades has become a focus of media and public attention. At the opposite end of the Earth, however, something more complex is happening.
A new NASA study shows that from 1978 to 2010 the total extent of sea ice surrounding Antarctica in the Southern Ocean grew by roughly 6,600 square miles every year, an area larger than the state of Connecticut. And previous research by the same authors indicates that this rate of increase has recently accelerated, up from an average rate of almost 4,300 square miles per year from 1978 to 2006.
“There’s been an overall increase in the sea ice cover in the Antarctic, which is the opposite of what is happening in the Arctic,” said lead author Claire Parkinson, a climate scientist with NASA’s Goddard Space Flight Center, Greenbelt, Md. “However, this growth rate is not nearly as large as the decrease in the Arctic.”
The Earth’s poles have very different geographies. The Arctic Ocean is surrounded by North America, Greenland and Eurasia. These large landmasses trap most of the sea ice, which builds up and retreats with each yearly freeze-and-melt cycle. But a large fraction of the older, thicker Arctic sea ice has disappeared over the last three decades. The shrinking summer ice cover has exposed dark ocean water that absorbs sunlight and warms up, leading to more ice loss.
On the opposite side of the planet, Antarctica is a continent circled by open waters that let sea ice expand during the winter but also offer less shelter during the melt season. Most of the Southern Ocean’s frozen cover grows and retreats every year, leading to little perennial sea ice in Antarctica.
Using passive-microwave data from NASA’s Nimbus 7 satellite and several Department of Defense meteorological satellites, Parkinson and colleague Don Cavalieri showed that sea ice changes were not uniform around Antarctica. Most of the growth from 1978 to 2010 occurred in the Ross Sea, which gained a little under 5,300 square miles of sea ice per year, with more modest increases in the Weddell Sea and Indian Ocean. At the same time, the region of the Bellingshausen and Amundsen Seas lost an average of about 3,200 square miles of ice every year.
› View larger The ice covering the Bellingshausen Sea, off the coast of Antarctica, as seen from a NASA Operation IceBridge flight on Oct. 13, 2012. Credit: NASA/Michael Studinger
Parkinson and Cavalieri said that the mixed pattern of ice growth and ice loss around the Southern Ocean could be due to changes in atmospheric circulation. Recent research points at the depleted ozone layer over Antarctica as a possible culprit. Ozone absorbs solar energy, so a lower concentration of this molecule can lead to a cooling of the stratosphere (the layer between six and 30 miles above the Earth’s surface) over Antarctica. At the same time, the temperate latitudes have been warming, and the differential in temperatures has strengthened the circumpolar winds flowing over the Ross Ice Shelf.
“Winds off the Ross Ice Shelf are getting stronger and stronger, and that causes the sea ice to be pushed off the coast, which generates areas of open water, polynyas,” said Josefino Comiso, a senior scientist at NASA Goddard. “The larger the coastal polynya, the more ice it produces, because in polynyas the water is in direct contact with the very cold winter atmosphere and rapidly freezes.” As the wind keeps blowing, the ice expands further to the north.
This year’s winter Antarctic sea ice maximum extent, reached two weeks after the Arctic Ocean’s ice cap experienced an all-time summertime low, was a record high for the satellite era of 7.49 million square miles, about 193,000 square miles more than its average maximum extent for the last three decades.
The Antarctic minimum extents, which are reached in the midst of the Antarctic summer, in February, have also slightly increased to 1.33 million square miles in 2012, or around 251,000 square miles more than the average minimum extent since 1979.
The numbers for the southernmost ocean, however, pale in comparison with the rates at which the Arctic has been losing sea ice – the extent of the ice cover of the Arctic Ocean in September 2012 was 1.32 million square miles below the average September extent from 1979 to 2000. The lost ice area is equivalent to roughly two Alaskas.
Parkinson said that the fact that some areas of the Southern Ocean are cooling and producing more sea ice does not disprove a warming climate.
“Climate does not change uniformly: The Earth is very large and the expectation definitely would be that there would be different changes in different regions of the world,” Parkinson said. “That’s true even if overall the system is warming.” Another recent NASA study showed that Antarctic sea ice slightly thinned from 2003 to 2008, but increases in the extent of the ice balanced the loss in thickness and led to an overall volume gain.
The new research, which used laser altimetry data from the Ice, Cloud, and land Elevation Satellite (ICESat), was the first to estimate sea ice thickness for the entire Southern Ocean from space.
Records of Antarctic sea ice thickness are much patchier than those of the Arctic, due to the logistical challenges of taking regular measurements in the fierce and frigid waters around Antarctica. The field data collection is mostly limited to research icebreakers that generally only travel there during spring and summer – so the sole means to get large-scale thickness measurements is from space.
“We have a good handle of the extent of the Antarctic sea ice, but the thickness has been the missing piece to monitor the sea ice mass balance,” said Thorsten Markus, one of the authors of the study and Project Scientist for ICESat-2, a satellite mission designed to replace the now defunct ICESat. ICESat-2 is scheduled to launch in 2016. “The extent can be greater, but if the sea ice gets thinner, the volume could stay the same.”
Maria-José Viñas
NASA’s Earth Science News Team
Robertvdl says:
October 24, 2012 at 5:00 pm
The Gulf Stream doesn’t warm Antarctica and if it wasn’t for the Gulf Steam, Norway wouldn’t even be growing icicles. What makes you think the one dimension involving latitude determines how a land warms?
Gary Lance says:
October 25, 2012 at 2:53 am
The arctic minimum is influenced by weather and that’s why I watch the weather in the arctic daily, but if that multi-year ice is lost for any reason, it’s gone and not coming back.
Yes it is. Once the old ice with its embedded black carbon melts out. We will see the current trend of increasing and record Arctic sea ice formation continue, resulting in increasing Arctic sea ice.
In the arctic, multi-year sea ice hides along the coast of northern Greenland and the CAA
Anthropomorphic sea ice, a novel concept.
The largest minimum was about 2.4 msk in 2003.
Nonsense. The largest minimum Antarctic sea ice extent was 3.9 million sq kms. Set, I recall twice since 2000.
The antarctic sea ice is free to expand in all directions around the continent and never comes close to other continents.
False. At its maximum extent extent Antarctic sea ice was closer to Australia and New Zealand than Antarctica.
The arctic used to have large amounts of sea ice that would survive a melt season and now it only has small amounts of any sea ice hugging North America where conditions have changed to allow an exit to the south
This sentence doesn’t make any sense. The facts are that older sea ice has melted faster than newer sea ice. Care to suggest a mechanism? Hint: embedded black carbon and increased solar insolation from reduced clouds.
The record for the arctic is much more complete than the antarctic, so the change is well documented.
In the satellite era the records are the same.
The sea ice isn’t free to expand in the arctic, because land and warm ocean currents limit it’s expansion.
You’ve already told us that Arctic sea ice gets exported. How is that not expansion?
In summary, the usual drivel from the Warmists. Short on facts and long on baseless speculation.
David A. Evans says:
October 24, 2012 at 5:14 pm
I didn’t say anything about absorbing sunlight, I said the poles get more sunlight around the time of the their summers than the equator does and it’s a fact, because the poles are getting sunlight 24 hours per day. The amount of time receiving sunlight makes up for the lower angle of the sun. It’s also a fact that the equator is getting it’s least amount of sunlight at that time. If our poles didn’t have ice, they could get quite warm during their summers. Oceans can retain enough heat to get it through a winter and land can have dry winters allowing it to quickly recover and warm. It isn’t a surprise that trees have grown in Antarctica, long after it started to cool. Trees shake off the snow and even if the ground is snow covered, it doesn’t reflect much sunlight. West Antarctica is a different animal, which is prone to changing back to that much different past. East Antarctica is a hugh ice age leftover.
“feet2thefire says:
October 24, 2012 at 9:46 pm
Antarctica’s ice is, of course, more important than the sea ice in the Arctic.
But the real issue of the Arctic sea ice is not each year’s minimum annual area.
The real issue (even though Arctic ice area is less important, anyway) is: Does the ice recover each year to a within-normal area? And it always does.
Steve Garcia”
The arctic sea ice doesn’t recover each year to it’s base period (1979 – 2008), which includes many of the recent years. In fact none of the 4 seasons they track sea ice shows normal levels. They all have a downward trend and that is expected to continue, until the summer season reaches zero.
“donald penman says:
October 24, 2012 at 10:26 pm
At the end of the day we are still left with the fact that we have Antarctic sea ice increasing while the Arctic sea ice is decreasing however people try to project this.All the Arctic sea ice that was lost in August has reformed in October and this seems to happen every year, it happened also in October 2007, so that we only had record ice gain in October this year because we had record ice loss in August. Just because some said the area where we have had rapid refreezing was clear of ice that was not true ,the sea ice just broke up and was transported elsewhere leaving the water still freezing cold.
http://stevengoddard.wordpress.com/2012/09/11/important-reminder-none-of-this-ice-exists/
Some people due to confirmation bias only see evidence for AGW never evidence against and if the Antarctic sea ice contridicts AGW then it has to be explained away but this years Arctic sea ice minimum was still evidence for AGW despite being caused by a strong storm in late August.”
You are the one with the bias. Warming should cause mass increase on the driest continent on Earth. So what if Antarctica warms to the point where it can’t freeze carbon dioxide, does that mean it’s still warm enough to snow?
The sea ice is not increasing in Antarctica and if it was the minimum sea ice would show so. Getting more sea ice because of increased precipitation and wind doesn’t prove it isn’t warming, in fact it’s consistent with warming. Precipitation on antarctic sea ice will melt away, like it does every year.
Antarctica is shielded by the strongest current in the world and circumpolar winds. It’s hard for a weather system to penetrate that shield.
adjacentworlds says:
October 24, 2012 at 11:08 pm
Sea ice extent means an area had 15% sea ice over a 5 day period. That means an area is included in sea ice extent when 85% of that area is ocean.
“D Böehm says:
October 25, 2012 at 3:06 am
Gary Lance says:
“The arctic minimum is influenced by weather and that’s why I watch the weather in the arctic daily,”
Get a life.”
In other words you can’t say anything about a subject and have to troll!
In 1900 whalers and sealers sailed over latitudes that had been charted as land a century earlier because of the multiyear sea ice. Present diminution of polar ice is primarily an artifact of the Little Ice Age. When Capt. Cook sailed the coasts north of the Bering Strait in 1778 he found ice everywhere “10 to 12 feet high” –meaning 100 feet thick. It was too cold for polar bears back then. Global warming has been upon us for some time now, no thanks to CO2. –AGF
Gary Lance says:
October 25, 2012 at 4:56 am
The Gulf Stream doesn’t warm Antarctica and if it wasn’t for the Gulf Steam, Norway wouldn’t even be growing icicles. What makes you think the one dimension involving latitude determines how a land warms?
so what do you think is the reason they can’t use the runway, Global Warming ?
“phlogiston says:
October 25, 2012 at 4:02 am
If we compare like with like, both the Arctic and the Antarctic winter sea ice maxima are increasing. The Antarctic summer sea ice minimum is currently zero every year. If this were to change to non-zero, that would be interesting.”
Where do you get your data?
The antarctic sea ice minimum is around 2 million square kilometers, although it’s usually less and it’s very consistent. It might even be as low as 1.9, if all satellite data was averaged and rounded off.
The arctic sea ice minimum is decreasing and has been rather consistently, though there are yearly weather related variations.
I use Cryosphere Today CT data and they prefer to use area, which is less than extent, but they try to estimate the percentage of sea ice in an area. Both are just numbers useful for trends, because the real measure is volume, which would mean how much sea ice is actually there. We don’t have accurate ways to measure volume or to show the quality of the sea ice. If CryoSat2 is launched in 2016, we may start getting accurate data, but the arctic sea ice may be gone by then and we’ll know the quality and volume rather accurately after it becomes ice free and starts to refreeze.
The problem with using extent or area is the amount of sea ice can decline, while the extent or area doesn’t. Sea ice that is 5 meters thick and 100% across an area is counted the same as sea ice 1 meter thick and 15% across an area for 5 days when considering extent. In 5 days that sea ice can move a good distance and if the areas are small enough, none of the original sea ice may be left in that area. NSIDC extent data comes from DOD NIC data. NIC data is designed to be analyzed daily and over cautiously to give navigation information to our Navy. As such the data is biased towards sea ice existing, when it might not be and that is done for safety reasons. Sea ice that is white can easily be identified, but sea ice with melt water on top can look like the ocean. The NIC has to devote it’s resources for the next day and isn’t concerned about correcting past data. The NIC has no interest besides daily safety for the Navy. I know this for a fact, because I’ve spoken with people who have done that work. The data sets are turned over to the NSIDC, who has an academic reason to determine if it’s sea ice or not. DMI analyzes the data at 30% concentration and I believe they use a 3 day running average. CT area tries to measure the area that is sea ice. PIOMAS tries to estimate sea ice volume.
Good job Gary!
From Gary Lance on October 24, 2012 at 1:45 pm (bold added):
I mention when alligators were in the Arctic. So now you say:
Etc. The continents were basically as they are today, except when that’s an Inconvenient Truth, then they no longer were basically as they are today.
You perform as well as a trained monkey when given the proper cues. Excellent work, Gary. Have a banana.
richardscourtney says:
October 25, 2012 at 4:35 am
If someone cares about your trolling reasons, they’re as bad as you are.
Sea ice wasn’t blown out of the arctic and the only thing that mattered was some of that ice removed from the pack was multi-year ice and maybe some first year sea ice that could have become lucky, if the weather pushed it in the right direction to avoid destruction by some miracle.
You have to ask yourself and others a question. Why are you bothering to discuss sea ice? I discuss it and analyze it, because it involves a very dynamic process that people glimpsing at a chart don’t see. Do you know why I’m the only one discussing multi-year sea ice? It’s because I’m the only one who is interested in sea ice and not some agenda. I know once the multi-year arctic sea ice is gone, the first year sea ice can’t survive a melting season. The only thing that will be of interest at that point is to see how long the arctic remains sea ice free, so next year’s sea ice can be estimated.
I look at it like it’s suppose to make sea ice. If more sea ice forms in the Bering Sea, that isn’t news when the Barents and Kara Seas have less than normal. The Bering Sea will be sea ice free every year. The thing to watch next year is whether the Canadian Archipelago becomes a player in exiting large amounts of sea ice. If so I can see someone pointing out the Northwest Passage didn’t open and ignoring the arctic flooded it with it’s precious multi-year ice to make it that way.
Philip Bradley says:
October 25, 2012 at 5:13 am
There is just way too much nonsense on your post to correct, like there isn’t black carbon on multi-year sea ice causing it to melt faster.
Stick around for a few years and see how wrong you were and let me define few further as in three!
I’ll bet on the sea ice being gone before you have a clue what it is or the dynamics involved in it being there.
From Gary Lance on October 25, 2012 at 8:04 am (bold added):
Wikipedia (bold added):
See the ESA Mission Overview.
Perhaps you’re referring to another CryoSat-type mission after the current one concludes.
As it is, CryoSat-2 has been measuring sea ice thickness, the data is available. They’re also using CryoSat-2 for high-resolution mapping of the ocean floor.
“agfosterjr says:
October 25, 2012 at 7:50 am
In 1900 whalers and sealers sailed over latitudes that had been charted as land a century earlier because of the multiyear sea ice. Present diminution of polar ice is primarily an artifact of the Little Ice Age. When Capt. Cook sailed the coasts north of the Bering Strait in 1778 he found ice everywhere “10 to 12 feet high” –meaning 100 feet thick. It was too cold for polar bears back then. Global warming has been upon us for some time now, no thanks to CO2. –AGF”
You don’t know the difference between sea ice and an iceberg.
Found it, Gary!
You were mistakenly referring to the ICESat-2 project by NASA.
Proposed launch date in 2016, if everything goes on schedule. Will carry a single instrument, a LIDAR, and can only measure elevation.
With the current US deficit woes, with the Europeans having already deployed more versatile satellites, with the Europeans and the Japanese willing to partner with the US on space projects and share costs…
And with the “problem” of loss of Arctic sea ice being ignored and considered beneficial…
Limited, pricey, addressing a non-issue. Offhand I severely doubt ICESat-2 will be launched in 2016, if ever.
“Robertvdl says:
October 25, 2012 at 7:58 am
Gary Lance says:
October 25, 2012 at 4:56 am
The Gulf Stream doesn’t warm Antarctica and if it wasn’t for the Gulf Steam, Norway wouldn’t even be growing icicles. What makes you think the one dimension involving latitude determines how a land warms?
so what do you think is the reason they can’t use the runway, Global Warming ?”
I haven’t examined it, but my first choice would be Rossby waves or meanders in the polar jet stream allowing it to warm there, while it dumps cold somewhere else. Our jet stream has been stalling weather conditions with similar meanders. High pressure over Antarctica and low pressure on the other side of their polar jet stream will cause Rossby waves. Rossby waves were discovered in 1939, so they have been around influencing weather for who knows how long. Antarctica is the coldest place on Earth and cold air is high pressure. If we could find weather data, I’d bet there were low pressure systems on the other side of the jet stream around that location.
The evidence shows the runway wasn’t used enough for carbon to become a problem, so it can’t be something easy to eliminate. It can’t be something like the latitude, because the Aussies have a claim on that area and know about it’s history for weather. It’s not suppose to get warm there at this time of year, but just as we have had exceptional springs, so can they. The antarcitc circle and the arctic circle aren’t the same, so that logic is a fail.
Rossby waves can stall conditions allowing prolonged weather that would have came and gone without them. They can dump cold at low latitudes and bring warmth to high latitudes.
The problem with the way people think about these things is it’s one dimensional thought. They don’t look for the obvious, because their agenda has consumed their brains. Everything has to be examined from their prejudicial side about global warming. We have very little weather information in the present about Antarctica, let alone a base period to compare with. You can’t make a case for warming or not, except an anecdotal case. We can say it was exceptionally warm for that area.
Gary Lance:
Your post addressed to me at October 25, 2012 at 8:57 am contains your usual twaddle which I do not deign to answer and it poses this question to which I am responding.
No, I don’t have to ask any question which you demand. Especially when you say you are asking the question because you “see” something which you cannot describe or define and you admit that others don’t see it.
Instead, I choose to ask you to justify your ignorant and unfounded assertions concerning Arctic ice loss. Therefore, I yet again ask you the questions (concerning your assertions) which you have so steadfastly refused to answer on the earlier Arctic ice thread.
For convenience of any who have not seen them, I copy the questions here. They are
1.
Please educate me on how “an ice free arctic … will be the most pivotal event related to the Earth that man has ever witnessed”.
This will be more “pivotal” than the exit from Africa, than the end of the last glaciation, than the invention of agriculture, and than the industrial revolution? How?
2.
You tell me, “The areas that will benefit from that change are not well populated and the areas who will be losers are well populated.”
Why is such a coincidence likely? And why will people not move if it happens?
Gary Lance, you made the assertions. Explain them, please. I have waited your answers for a long time.
Richard
kadaka (KD Knoebel) says:
October 25, 2012 at 8:27 am
Do you think our world was like this one?
http://www.earthscrust.org/science/transects/img/india/image005.jpg
The ocean circulation patterns were very different, but I see you are trying to get us back to Hothouse Earth.
kadaka (KD Knoebel) says:
October 25, 2012 at 9:09 am
I meant IceSat2.
Friends:
I had to copy this in case anybody missed it.
At October 25, 2012 at 9:55 am Gary Lance wrote:
Yes, really! Gary Lance wrote it! You could not make this stuff up.
Richard
Gary Lance says:
October 24, 2012 at 1:45 pm
“Sunlight in the Arctic at the height of summer is only 3% of normal sunlight as it comes in at a low angle and through a greater distance of atmosphere (the W/m^2 is down 97%). Any heating of the water will be near the surface and will be rapidly lost to evaporative cooling.”
[adjacent paragraph:]
“The North Pole gets more sunlight at the height of summer than the equator. Hint: It’s getting it 24 hours per day.”
=====================================================================
So, it gets “only 3% of normal sunlight” while at the same time getting “more sunlight at the height of summer than the equator”! I’m not sure 24 hours is long enough to accomplish this unless equatorial days are just a few minutes long. The latter of his two claims is correct, and thoroughly contradicts his first claim–one wonders where he came up with this nonsense, but the humorous thing is he doesn’t grasp the contradiction.
Then he says to me: “You don’t know the difference between sea ice and an iceberg.” Well maybe Capt. Cook didn’t either; sure, icebergs 500 miles long are seen all the time.
And of course Kadaka is right: during the Cretaceous the continents were a whole lot different, which apparently Gary Lance has only just learned.
Stick around, Gary, and we will separate you from the likes of those who believe global warming is at fault for the melting runway at Wilkins. –AGF
Gary Lance,
Still thread bombing, I see. You really need to get a life. You’re making no headway convincing anyone here, despite your incessant posting of alarmist talking points 24/7.
“kadaka (KD Knoebel) says:
October 25, 2012 at 9:43 am
Found it, Gary!
You were mistakenly referring to the ICESat-2 project by NASA.
Proposed launch date in 2016, if everything goes on schedule. Will carry a single instrument, a LIDAR, and can only measure elevation.
With the current US deficit woes, with the Europeans having already deployed more versatile satellites, with the Europeans and the Japanese willing to partner with the US on space projects and share costs…
And with the “problem” of loss of Arctic sea ice being ignored and considered beneficial…
Limited, pricey, addressing a non-issue. Offhand I severely doubt ICESat-2 will be launched in 2016, if ever.”
IceSat and GRACE work as a team, plus IceSat is needed for ice sheets. I think it will be launched, because ice sheets are going to replace the strategic interest in the satellites. I don’t expect the arctic sea ice to be around in 2016 to give the Navy problems. They will only be concerned about icebergs and remnants of ice shelves by then. They could bore holes and calculate ice thickness based on meteorological stats, basically figuring out how fast and thick the ice will grow.
When we first put nuclear submarines under in the arctic, one of the first things they did was surface, in fact it was done many times as if they were training. Those submarines were designed to carry cruise missiles, so they needed to surface and that requires information on the sea ice thickness. Stealth became an early part of submarine warfare, so using active sonar was an early taboo, because it gave away your position. I know there have been many advances in sonar and I’ve often wondered if the Navy has ever put devices that could give good sonar imaging and whether it could image the sea ice thickness from below. You would think if two navies were playing cat and mouse with each other that such devices would be logical.
Some ancient maps seem to indicate the extent of the southern ice during the LIA. Here’s one:
http://www.gracegalleries.com/images/WOR/WOR159.jpg
Here’s another:
http://www.gracegalleries.com/images/WOR/WOR158.jpg
The Terra Australlis Incognita shrunk first through the voyages of exploration and second through receding ice. There’s not much left to shrink. –AGF