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2011 Arctic Sea Ice Thread

BenBurch

Gatekeeper of The Left
BenBurch
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OK, as in prior years, this is a thread on Arctic Sea Ice for tracking sea ice over the course of the 2011 melt season.

A few rules about this thread;

1. This is not an AGW thread. Posting AGW topics in here is explicitly forbidden by moderator directive.
2. This is about Sea Ice only.
3. You may speculate on the trajectory of Sea Ice melting in here.
4. You may post data from official sources and news articles from the science press in this thread.
5. No politics.

Now, to start us off let us discuss the three measures of Sea Ice that are often misunderstood;

Sea Ice Extent; This is the total area of sea that is at least 15% ice-covered, so this can include a lot of open water, no open water, or anything in between. This is an easy measurement to make, and is useful for navigation; unless you are an icebreaker you do not want to sail into an area that is 15% ice. However, this is a very misleading measurement at times when you want to ascertain how much ice has melted.

Sea Ice Area; This is a better measurement in that it considers just the area taken up by ice. If 1 km2 is 20% ice-covered, that is .2 km2 area. So though this measurement CAN track Extent fairly closely, there is no guarantee it will, and it can diverge markedly under the right conditions. However, this tells you nothing about the thickness of the ice; It can be 1 cm thick, or 3 m thick and it is all the same in this measure, what counts is the area it covers. This measurement is a good way to judge the amount of sunlight rejected to space by white ice as opposed to dark water.

Sea Ice Volume; This is the actual physical volume of ice in polar waters. It is probably the best measure of how far the loss of polar ice has progressed.

Anomaly plots; When you compare the ice that on average would have been found on a particular date or range of dates, in any of the above measures, and subtract that from the number you measure, you get the first derivative of the that measure, and you can see how much ahead or behind the average you are. This is very useful as it is difficult to look at the sinusoidal annual cycle these numbers go through, and get a sense of comparison between two cycles. This removes the annual signal and just shows you how it had been modulated.
 
So should I invest in Northwest Passage Cargo Lines now?
 
Travis said:
So should I invest in Northwest Passage Cargo Lines now?
Click to expand...

Absolutely. I know the people involved and can get you in on the bottom rung. Just email me your bank details and we'll talk, yeah?

If you're the thinking of long-term investment you can't afford to ignore the economic implications of a seasonally open Arctic trade-route between Europe and the Far East, with Russia along the way. The economic world will be very different; something understood long ago, which is why so many died trying to find a NW or NE Passage. The risk was great but the potential rewards were tremendous.

Go short on the Panama Canal is my advice.
 
I wonder if the folks at IJIS are ok, they havn't updated their graph and I am missing my daily fix.

Hoping to call the start of the melt season by their graph.

Cryosphere today looks like it is on.

My prediction is for a new low in extent for this summers minimum.
 
Predicting how Arctic sea-ice is a tricky business, since it's unprecedented in modern human experience. I expect it to be quite closely analogous to the break-up of seasonal lake and river-ice.

Ice can thin for a long time without looking any different from the top. Then one day you see a patch of water under the ice. The next day you see them here and there. Each day you see more of them, then one day lots of them, then suddenly the whole sheet disintegrates. Mostly thinned to zero, and the rest just washed away.

I think we're a long way down that path in the Arctic. I expect this year to produce very little attention from the denial machine, if any. Steve Goddard was thrown under the bus last year already, George Will didn't write an editorial on sea-ice recovery this year, and Bastardi's taken early retirement from what Ive heard. That leaves WattsUpMyButt still working the email angle and no doubt dreading the summer. Even Antarctic sea-ice is showing signs of not playing ball.

It's a lot easier to predict the denial machine than it is to predict Arctic sea-ice :).
 
Measurements of Winter Arctic Sea Ice Shows Continuing Ice Loss, Study Finds

ScienceDaily (Mar. 23, 2011) — The 2011 Arctic sea ice extent maximum that marks the beginning of the melt season appears to be tied for the lowest ever measured by satellites, say scientists at the University of Colorado Boulder's National Snow and Ice Data Center.

The CU-Boulder research team believes the lowest annual maximum ice extent of 5,650,000 square miles occurred on March 7. The maximum ice extent was 463,000 square miles below the 1979-2000 average, an area slightly larger than the states of Texas and California combined. The 2011 measurements were tied with those from 2006 as the lowest maximum sea ice extents measured since satellite record keeping began in 1979.
Click to expand...

more
http://www.sciencedaily.com/releases/2011/03/110324104143.htm
 
why is it lowest ice extent yet a cold winter?

Warm water causes extra-cold winters in northeastern North America and northeastern Asia
March 30, 2011

http://cdn.physorg.com/newman/gfx/news/hires/2011/warmwatercau.jpg
This map shows sea‑surface temperatures averaged over eight days in September 2001, as measured by NASA's Terra satellite. Dark red represents warm water (32 degrees Celsius) and purple is cold (‑2 degrees Celsius). The Gulf Stream can be seen as the orange strip extending from the eastern U.S. toward the Atlantic. Credit: Ronald Vogel, SAIC for NASA GSFC

If you're sitting on a bench in New York City's Central Park in winter, you're probably freezing. After all, the average temperature in January is 32 degrees Fahrenheit. But if you were just across the pond in Porto, Portugal, which shares New York's latitude, you'd be much warmer—the average temperature is a balmy 48 degrees Fahrenheit.

Throughout northern Europe, average winter temperatures are at least 10 degrees Fahrenheit warmer than similar latitudes on the northeastern coast of the United States and the eastern coast of Canada. The same phenomenon happens over the Pacific, where winters on the northeastern coast of Asia are colder than in the Pacific Northwest.

Researchers at the California Institute of Technology (Caltech) have now found a mechanism that helps explain these chillier winters—and the culprit is warm water off the eastern coasts of these continents.

"These warm ocean waters off the eastern coast actually make it cold in winter—it's counterintuitive," says Tapio Schneider, the Frank J. Gilloon Professor of Environmental Science and Engineering.

Schneider and Yohai Kaspi, a postdoctoral fellow at Caltech, describe their work in a paper published in the March 31 issue of the journal Nature.

Using computer simulations of the atmosphere, the researchers found that the warm water off an eastern coast will heat the air above it and lead to the formation of atmospheric waves, drawing cold air from the northern polar region. The cold air forms a plume just to the west of the warm water. In the case of the Atlantic Ocean, this means the frigid air ends up right over the northeastern United States and eastern Canada.

http://cdn.physorg.com/newman/gfx/news/hires/2011/1-warmwatercau.jpg

This image, taken by NASA's Terra satellite in March 2003, shows a much colder North America than Europe‑‑even at equal latitudes. White represents areas with more than 50 percent snow cover. NASA's Aqua satellite also measured water temperatures. Water between 0 and ‑15 degrees Celsius is in pink, while water between ‑15 and ‑28 degrees Celsius is in purple. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio; George Riggs (NASA/SSAI).

For decades, the conventional explanation for the cross-oceanic temperature difference was that the Gulf Stream delivers warm water from the Gulf of Mexico to northern Europe. But in 2002, research showed that ocean currents aren't capable of transporting that much heat, instead contributing only up to 10 percent of the warming.

Kaspi's and Schneider's work reveals a mechanism that helps create a temperature contrast not by warming Europe, but by cooling the eastern United States. Surprisingly, it's the Gulf Stream that causes this cooling.

In the northern hemisphere, the subtropical ocean currents circulate in a clockwise direction, bringing an influx of warm water from low latitudes into the western part of the ocean. These warm waters heat the air above it.

"It's not that the warm Gulf Stream waters substantially heat up Europe," Kaspi says. "But the existence of the Gulf Stream near the U.S. coast is causing the cooling of the northeastern United States."

The researchers' computer model simulates a simplified, ocean-covered Earth with a warm region to mimic the coastal reservoir of warm water in the Gulf Stream. The simulations show that such a warm spot produces so-called Rossby waves.

Generally speaking, Rossby waves are large atmospheric waves—with wavelengths that stretch for more than 1,000 miles. They form when the path of moving air is deflected due to Earth's rotation, a phenomenon known as the Coriolis effect. In a way similar to how gravity is the force that produces water waves on the surface of a pond, the Coriolis force is responsible for Rossby waves.

In the simulations, the warm water produces stationary Rossby waves, in which the peaks and valleys of the waves don't move, but the waves still transfer energy. In the northern hemisphere, the stationary Rossby waves cause air to circulate in a clockwise direction just to the west of the warm region. To the east of the warm region, the air swirls in the counterclockwise direction. These motions draw in cold air from the north, balancing the heating over the warm ocean waters.
Click to expand...

more

http://www.physorg.com/news/2011-03-extra-cold-winters-northeastern-north-america.html
Click to expand...
 
Gulf Stream could be threatened by Arctic flush


Rapid warming in the Arctic is creating a new and fast-growing pool of fresh water in the Arctic Ocean. Measuring at least 7500 cubic kilometres, it could flush into the Atlantic Ocean and slow the Gulf Stream, bringing colder winters to Europe.
The water is mostly coming from melting permafrost and rising rainfall, which is increasing flows in Siberian rivers that drain into the Arctic, such as the Ob and Yenisei.


More comes from melting sea ice, says Laura de Steur of the Royal Netherlands Institute of Sea Research in 't Horntje, who is tracking the build-up.


Salinity anomalies like this are a regular feature of the Arctic. The last major event occurred in the 1960s. They happen when strong winds circling the Arctic restrict southward water movement. Eventually, the winds falter and the water flushes into the Atlantic through the Fram strait, between Greenland and Europe.


Recent Arctic melting runs the risk of increasing the freshwater build-up, potentially making the consequences of the eventual breakout more extreme, says de Steur. This is the first time that scientists have measured a salinity anomaly in the Arctic in detail, and in time to analyse how the freshwater pool breaks out into the North Atlantic.
Click to expand...
more - and what happened last time this happened to the extreme..
http://www.newscientist.com/article...-flush.html?DCMP=OTC-rss&nsref=climate-change

Interesting times......:garfield:
 
When they pull the Icebreakers from the Great Lakes I'd start thinking about year round passage through the North west Passage.
At the moment there's a lot of tourists 'doing' the Northwest Passage every year.
Google will bring the tour booking page up...
 
Measurements of Winter Arctic Sea Ice Shows Continuing Ice Loss

http://www.sciencedaily.com/releases/2011/03/110324104143.htm

ScienceDaily (Mar. 30, 2011) — The 2011 Arctic sea ice extent maximum that marks the beginning of the melt season appears to be tied for the lowest ever measured by satellites, say scientists at the University of Colorado Boulder's National Snow and Ice Data Center.

The CU-Boulder research team believes the lowest annual maximum ice extent of 5,650,000 square miles occurred on March 7. The maximum ice extent was 463,000 square miles below the 1979-2000 average, an area slightly larger than the states of Texas and California combined. The 2011 measurements were tied with those from 2006 as the lowest maximum sea ice extents measured since satellite record keeping began in 1979.

Virtually all climate scientists believe shrinking Arctic sea ice is tied to warming temperatures in the region caused by an increase in human-produced greenhouse gases being pumped into Earth's atmosphere. Because of the spiraling downward trend of Arctic sea ice extent in the last decade, some CU scientists are predicting the Arctic Ocean may be ice free in the summers within the next several decades.

<SNIP>
Click to expand...
 
BenBurch said:
OK, as in prior years, this is a thread on Arctic Sea Ice for tracking sea ice over the course of the 2011 melt season.

A few rules about this thread;

1. This is not an AGW thread. Posting AGW topics in here is explicitly forbidden by moderator directive.
2. This is about Sea Ice only.
3. You may speculate on the trajectory of Sea Ice melting in here.
4. You may post data from official sources and news articles from the science press in this thread.
5. No politics.

Now, to start us off let us discuss the three measures of Sea Ice that are often misunderstood;

Sea Ice Extent; This is the total area of sea that is at least 15% ice-covered, so this can include a lot of open water, no open water, or anything in between. This is an easy measurement to make, and is useful for navigation; unless you are an icebreaker you do not want to sail into an area that is 15% ice. However, this is a very misleading measurement at times when you want to ascertain how much ice has melted.

Sea Ice Area; This is a better measurement in that it considers just the area taken up by ice. If 1 km2 is 20% ice-covered, that is .2 km2 area. So though this measurement CAN track Extent fairly closely, there is no guarantee it will, and it can diverge markedly under the right conditions. However, this tells you nothing about the thickness of the ice; It can be 1 cm thick, or 3 m thick and it is all the same in this measure, what counts is the area it covers. This measurement is a good way to judge the amount of sunlight rejected to space by white ice as opposed to dark water.

Sea Ice Volume; This is the actual physical volume of ice in polar waters. It is probably the best measure of how far the loss of polar ice has progressed.

Anomaly plots; When you compare the ice that on average would have been found on a particular date or range of dates, in any of the above measures, and subtract that from the number you measure, you get the first derivative of the that measure, and you can see how much ahead or behind the average you are. This is very useful as it is difficult to look at the sinusoidal annual cycle these numbers go through, and get a sense of comparison between two cycles. This removes the annual signal and just shows you how it had been modulated.
Click to expand...

You state "three measures" and then you define four terms, how can we trust a thread that begins with such deceptive and misleading practices!?!?

:)

Seriously, should be an interesting summer. I believe my original prediction from several years back was for 2015 as the first ice-free period, I'll have to dig back to confirm, but it looks like the arctic is on-track, or perhaps even a bit ahead of track for that prediction. Given that when I made it, it was about 20 years ahead of most official predictions, it'll be interesting to see how far off I, and the larger professional community were off,...back then.
 
I suggested by 2015 for an ice-free summer Arctic, but my record on sea-ice prediction is not stellar :o.

I see it as very muh like ice break-up on a pond or stream. The ice seems unchanging for a while, then the melt starts to come through from below and after that things happen very quickly. We're in that final stage now, I think.

Any sign of a Round-the-World yacht-race the short way yet? That can't be far off.
 
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