Posts Tagged ‘Cryosphere Today’

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When was the last time this happened?

August 4, 2013

We are in the middle of the Arctic melt season.  The rate of sea ice melt is at it greatest from about mid-June (day 156) to about mid-August (day 216).  Thirty years ago, according to satellite data, the arctic lost about 5 million square kilometers of ice during this period.  For the last decade the arctic has lost closer to 6 million square kilometers of ice during this period.  That averages out to about 100,000 kilometers per day.  Of course, it recovers all, or most, of that area during the freezing season.  This point is illustrated in the follow image from Cryosphere Today (8/4/13, with my annotation).

Northern Hemisphere sea ice area 5

Now look closer.

Northern Hemisphere sea ice area 4

Notice that for the last 10 days there has been no drop in sea ice area. We would have expected a loss on the order of one million square kilometers!  Either something extraordinary is happening, or there is a problem with the satellite data.

When was the last time this happened this time of year?  This image shows the entire history of the arctic (which everyone knows really means back to 1979).  This is “unprecedented!”

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Arctic sea ice gone by 2015? A challenge to David Barber.

December 10, 2008
Here we go again. Last March I wrote about the media predictions that the Arctic sea ice would be gone by the summer of 2012. As I showed back then, those wild predictions were based on a simple extrapolation of the minimum summer sea ice extents of 2006 and 2007.

 

I’ll repeat the basic facts:

The sea ice area in the Arctic has been monitored by satellite for almost 30 years, since 1979. The area of the ice rises and falls, as you would expect, as the year cycles through its seasons. It reaches its yearly minimum by late September or early October. On the average, this minimum has been declining for the last 30 years. After October the northern sea ice area increases until it reaches a maximum in late March or early April each year. The yearly cycle is huge. Typically, about 60% of the total sea ice area melts away as is goes from yearly maximum to the yearly minimum.

The 2007 melt season was very severe and the Arctic sea ice area anomaly reached its lowest level since satellite tracking began.  But that low level was immediately followed by an unprecedented rise in sea ice area in the Arctic in the months following the 2007 summer melt season. The 2008 melt season was quite severe, but not as severe as the 2007 melt season. In order to go from the minimum ice extent of 2007 to zero ice in 2012, the Arctic sea ice extent minimum needs to drop an average of about 600,000 square kilometers per year. But the Arctic ended up with slightly more ice area (about 100,000 square kilometers more) after the 2008 melt season than after the 2007 melt season.  Figure 1, below sums it up.

Figure 1

Figure 1

New predictions of meltdown

Now along comes David Barber  from the University of Manitoba, who estimates that the Arctic Basin will be ice free by the summer of 2015. The Star Phoenix reports:

The ice that has covered the Arctic basin for a million years will be gone in little more than six years because of global warming, a University of Manitoba geoscientist said. And David Barber said that once the sea ice is gone, more humans will be attracted to the Arctic, bringing with them even more ill effects…He said he estimates the Arctic sea should see its first ice-free summer around 2015…Barber has said before the Arctic basin would be free of summer sea ice some time between 2013 and 2030. But their research about recent changes in the Arctic has allowed them to pinpoint the date even closer.

Barber sounds like a smart guy, and was the scientist in charge of a $40-million Arctic research project, the Circumpolar Flaw Lead System Study. He will present his preliminary findings at the International Arctic Change 2008 conference  in Quebec. However, his track record for predictions is rather spotty. Earlier this year National Geographic reported:

“We’re actually projecting this year that the North Pole may be free of ice for the first time [in history],” David Barber, of the University of Manitoba, told National Geographic News aboard the C.C.G.S. Amundsen, a Canadian research icebreaker.”

Prediction for summer of 2008 didn’t work out

The Arctic sea ice concentration reached its minimum around September 15th this year. Figure 2, below, from the Polar Research Group at the University of Illinois, shows the distribution of ice in the Arctic on that day. As you can see, the North Pole was not even close to being ice free. Figure 3 shows the Arctic Basin sea ice area for the last 365 days. Note that in mid-September the the sea ice area anomaly for the Arctic Basin was about negative 0.75 million square kilometers, but there were still 2.5 million square kilometers of ice yet to melt. Again, not even close to zero.

Figure 2

 Figure 2. Arctic Sea Ice Concentration on September 15th, 2008, when the Arctic sea ice reached its minimum for the year. Image from the University of Illinois Polar Research Group.

Figure 3. Figure 3. Arctic Basin sea ice area for the last 365 days.  In mid-September the sea ice anomaly was negative 0.75 million square kilometers, but there were 2.5 million square kilometers more than zero.  Image from the University of Illinois Polar Research Group.  Click on image to see clearer version. 

 
Those who like to parse words will note that National Geographic piece did not quote Barber as saying the “Arctic Basin” or the “Arctic Ocean” would be ice free during the summer of 2008.  They will correctly point out that he said “the North Pole.”  My answer to that is “So what.”  The North Pole has certainly seen open water in modern times, as attested to by the following images:
Figure 4.

 Figure 4. Skate (SSN-578), surfaced at the North Pole, 17 March 1959. US Navy photo courtesy of tripod.com. This image is from NavSource Online: Submarine Photo Archive

Figure 5.

 Figure 5. Seadragon (SSN-584), foreground, and her sister Skate (SSN-578) during a rendezvous at the North Pole in August 1962. Note the men on the ice beyond the submarines. USN photo from The American Submarine, by Norman Polmar. This image is from NavSource Online: Submarine Photo Archive

 

What about Barber’s prediction for 2015?

The December 5th StarPhoenix article mentioned above says that according to Barber, “The ice that has covered the Arctic basin for a million years will be gone in little more than six years because of global warming.”  I wonder if Barber can seriously believe that the Arctic Basin has been continuously ice covered for “a million years.”  There is considerable evidence  that the entire Arctic region was warmer just several thousand years ago than it is now. 

Open water from the northern coast of Greenland to the North Pole likely occurred in the not too distant past.  According to Science Daily, Astrid Lysa and colleagues have studied shore features, driftwood samples, microfossils and shore sediments from Northern Greenland. Science Daily reports:

 “The architecture of a sandy shore depends partly on whether wave activity or pack ice has influenced its formation. Beach ridges, which are generally distinct, very long, broad features running parallel to the shoreline, form when there is wave activity and occasional storms. This requires periodically open water,” Astrid Lyså explains.

Pack-ice ridges which form when drift ice is pressed onto the seashore piling up shore sediments that lie in its path, have a completely different character. They are generally shorter, narrower and more irregular in shape.

“The beach ridges which we have had dated to about 6000-7000 years ago were shaped by wave activity,” says Astrid Lyså. They are located at the mouth of Independence Fjord in North Greenland, on an open, flat plain facing directly onto the Arctic Ocean. Today, drift ice forms a continuous cover from the land here.

Astrid Lyså says that such old beach formations require that the sea all the way to the North Pole was periodically ice free for a long time.

“This stands in sharp contrast to the present-day situation where only ridges piled up by pack ice are being formed,” she says.

Funder and Kjaer reported similar results at the 2007 fall meeting of the American Geophysical Union. They point out that “Presently the North Greenland coastline is permanently beleaguered by pack ice…” but “that for a period in the Early Holocene, probably for a millennium or more, the Arctic Ocean was free of sea ice at least for short periods in the summer.” They date this time period to sometime between 8500 and 6000 years ago.  (Update 7/8/10 – Funder now believes “that multiyear sea ice was reduced to between half and a third of the present during the Holocene Thermal Optimum.”  Thanks to Kevin O’Neill and his persistence  in making this correction.)

An Open Challenge to David Barber

I am concerned about climate exaggerations and the effect  they have on public policy makers.  It seems quite clear that David Barber was off the mark when he predicted that “this year that the North Pole may be free of ice for the first time,” because neither the Arctic Ocean, the Arctic Basin nor the North Pole were ice free this past summer.  The North Pole being ice free is not that unusual, and the entire Arctic was probably ice free a relatively short 7,000 years ago.

Now Barber has made the slightly longer term prediction that “The ice that has covered the Arctic basin for a million years will be gone in little more than six years.”  I propose a friendly wager based on this prediction.  I will bet David Barber $1000(US) that the ice covering the Arctic Basin will not be gone anytime before December 31st, 2015.  The bet would involve no transfer of  cash between myself or Barber, but rather, the loser will pay the sum to a charitable organization designated by the winner.

 Definition of terms.  The Arctic Basin is defined by the regional map at Cryosphere Today.  “Gone” means the Arctic Basin sea ice area is less that 100,000 square kilometers, according to National Center for Environmental Prediction/NOAA as presented at Cryosphere Today .  Charitable organizations will be agreed upon at the time the bet is initiated. 

David Barber is a smart guy and evidently an expert in his field.  Taking on a wager with an amateur like me should be like shooting fish in a barrel.  I look forward to reaching an agreement soon.

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An easy climate change / energy quiz

November 13, 2008

Here is a simple, fun, 10 question quiz that covers a sample of climate change and/or energy issues.   Simply check the appropriate box and push the “vote” button for each question.  After you have pushed the vote button you will see the accumulated wisdom of everybody who has answered that question so far.  You can even leave a comment for any question, which I encourage.

Note that several of the questions requiring numerical answers have “order of magnitude” choices.   That is, they require “back of the envelope” type approximations, not high precision.

At the bottom of the quiz you will find a link to a solutions page, with links to supporting evidence, and “back of the envelope” calculations.  If you want, you can look at the solutions first and then take the quiz – but that would be cheating!

After enough people have answered the questions I will post the results at ClimateSanity.

Have fun!

 QUESTION 1. 

 Here are five false color images of the sea ice in the arctic.  The images represent the ice on five year intervals on July 18th of 1988, 1993, 1998, 2003, and 2008.  Your task is to use your knowledge of changing conditions in the Arctic to put them in the proper chronological order.  Note that each image uses the same color scale (shown in the upper left corner of each image) to indicate the density of ice as a function of position. 

Image 1

Image 2

Image 3

Image 4

Image 5

 

Question 2

 

Question 3

In the fall of 2007, after the northern summer melt season, the Arctic sea ice extent anomaly reached its lowest level since satellite monitoring began in 1979.  This was followed by warnings that the Arctic ice could be completely gone by the summer of 2012. 

 

Question 4

In 1979 the worst nuclear accident in US history happened at Three Mile Island nuclear power plant near Middletown, Pennsylvania. 

 

Question 5

A rising sea level is one of the feared symptoms of global warming.  According to the Jason and Topax satellite tracking of ocean levels, the average sea level rise rate for the last 10 years has been about 3.2 mm per year.  This is interpreted by some to indicate an accelerating sea level rise rate.  IPCC expert Simon Holgate’s 2004 data (Holgate, S.J., and P.L. Woodworth, 2004: Evidence for enhanced coastal sea level rise during the 1990s. Geophys. Res. Lett., 31, L07305, doi:10.1029/2004GL019626.) was prominently featured in the IPCC’s Fourth Assessment Report (AR4, Working Group 1: The Physical Science Basis of Climate change, Chapter 5).  In a more recent 2007 paper (S.J. Holgate, “On decadal rates of sea level change during the twentieth century“, Geophysical Research Letters34: GL019626 (2007)., Holgate reconstructed sea level rise rates from high quality tidal gauge data going back to about 1900.

 

Question 6

NASA Scientist James Hansen estimated a sea level rise of 15 feet for the 21st century.

 

Question 7

The northern coast of Greenland is at 83.5 degrees north latitude.  It is the closest land to the North Pole.  Satellite data since 1979 has always shown this region locked in sea ice.  If global warming were to result in an ice free arctic sometime during this century, it is believed that this area would be the last place to lose its summer ice.

 

Question 8

Compact fluorescent light bulbs use only 25% of the energy of an incandescent light bulb to give the same number of lumens of light.

 

Question 9

 

Question 10

Since 1963 Africa’s Lake Chad has experienced severe shrinkage.  While atmospheric CO2 levels have continuously increased since 1963, the surface area of the lake has dropped from about 25,000 square kilometers to about 1,500 square kilometers.  This fact has been presented by Al Gore and others as a consequence of anthropogenically induced global warming.  Of course, this evidence must be considered in comparison to how the lake was changing when CO2 levels were not increasing. 

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***Click here for quiz solutions***

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