Tag Archives: Sea ice

Beaufort Sea Polar Bears

Three days ago I read an article dramatizing the rapid reduction in Polar Bear populations in a sub-region of the Arctic.  The Beaufort Sea population had been reduced by 40% between 2004 and 2010.  I was a bit surprised by this statistic because I had seen many recent articles that had said Polar Bear populations had not been in recent decline.

I wondered if it was a regional issue or was it really the beginning of the end for the Polar Bear.  And then I read a bit more.   The 2010 Polar Bear population estimate was 900 bears down from 1250-2000 in 2004.  How can we have a precise number for 2010 and such a wide range only 6 years earlier?  Have we become expert Polar Bear counters in just 6 years?  Perhaps the 900 bears is a range value too.  If so what is the range?

The article used indirect counting methods so there must have been a range of values.  Bears were tagged and then survival rates of bears found years later were compared to past data.  Incomplete data in Canada in 2004 explained the range in the 2004 to 2006 data.   OK, but 900 sounds like an estimate to me.  The study might be an excellent proxy; it is beyond my expertise.  I still want more precise data.

And that is only the beginning of this data accumulation problem.  We really don’t have much data…and that is a big problem.

I wonder how many bears were wandering around in 1940 at the end of the last mini warming cycle?  Perhaps 2000 bears is too many for the local ecosystem?   How did Polar Bears fare some 130,000 years ago when sea level was 6 meters higher than it is today?  And how have the bears fared since 2010.  Why is there no recent update?

I don’t know the answer to any of those questions.   I’d go a step further and say that nobody really knows.  But too many of the scientists studying the recent decline KNOW the cause, reduced sea ice. And these same scientists seem to know why the sea ice has reduced, man caused climate change!

Maybe, maybe not.

Sea ice data is only 34 years old. And the best data is only 4 years old.  Just 4 years ago we began accumulating accurate data on sea ice thickness?  Anyone interested can visit the Snow and Ice Data Center website.

What has happened to Polar Bear populations since 2010? How have other regions in the Arctic fared?  What were the Polar Bear populations 40 years ago when hunting was allowed?  Or 400 years ago, during the little ice age?  Or 40,000 years ago when there was lots more ice, ice all the way down to NYC?

So many questions!  Oh yes, two more questions.  Did they need a global warming angle to get funding for their study?  And who paid for the study?

Don’t get me wrong.  I think man probably has caused some of the impacts being witnessed.  How much is an extraordinarily difficult science problem.  I wish society were be a bit more circumspect.  Sometimes problems are not that simple   All too often we humans looks for easy simple answers to difficult complicated questions.

 

 

 

 

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Sea Level Confusion — Part 2

I’ve been reading, trying to understand better why sea level varies so much from location to location. I conducted a google search and found a site affiliated with Yale University.

The site is called Environment 360.   An article titled The Secret of Sea Level Rise: It Will Vary Greatly By Region  provided a bit of insight and some climate propaganda.  The climate propaganda makes me a bit nervous. If the author is inclined to misrepresent in one area, perhaps the rest of the article is less than impartial.  The first paragraph included the following tidbit:

Recent projections suggest a global average warming of perhaps 3 to 4 degrees C, or 5.4 to 7 degrees F, by the end of this century.

A little later in the article:

Sea level, according to the best current projections, could rise by about a meter by 2100, in large part due to melting of the Greenland and West Antarctic ice sheets.

The article was written in 2010.   Best current projections, give me a break.  In 2010 his best projections would have been IPCC AR4 report published in September of 2007.   That report made no predictions about Greenland and said that data on the Antarctic ice sheet was inconclusive.  AR4 predicted the following in a section titled Projections for Future Changes in Climate:

For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios

Almost immediately thereafter  sea level rise by 2100 makes an appearance in the form of a chart.  The sea level rise that matched 4 degrees C was …are you ready…between .26 and .59 meter.   The data in the chart (labeled SPM 1 in AR4) showed a range of best guess temperatures from 1.1 to 4.0 degrees C.   4.0 was the highest best guess on the chart.   The author took the highest number possible, and made it sound like the most likely event!

And so far temperature predictions made in the AR4 report have been wild high.

Since Y2K there has been no net change in the temperature of the Earth’s surface.  Temperatures peaked in 1998 and have been wandering in  a narrow range for some 15 years.   Carbon dioxide has been rising steadily, temperature has not.  I have no idea what kind of projections he was referring to.   IPCC projections will, in AR5, almost certainly be less specific.  Nobody likes to have their mistakes so easily documented.

That said the article offers some interesting tidbits about why sea level changes.  Most are short term lasting anywhere from a few days to up to 30 years.   Wind, atmospheric pressure, and changes in the ocean bottom are discussed.    None seemed to help explain the errant data I was seeing (see my last post).   And then I read about gravity!

Supposedly, changes in gravity at the poles can impact sea level.   When the Arctic ice cap shrinks (as it has been doing since the 1970’s) this changes the gravitational force in the area.  Sea level goes down.   And this article predicted significant changes.   The whole thing sounded a bit S.W.A.G.-ish to me.  And given the exaggeration in the beginning of the article I had suspicions.   Still it is an interesting notion.

Another article said that when ice in Greenland melts it can take up to 30 years for that change in sea level to work it’s way around the world.   Another article talked about how difficult is to measure sea level.   The subject seethes with SWAG potential.

NOAA keeps all sorts of data on sea level.   They monitor hundreds of sites (perhaps thousands).   But the sites are not uniformly distributed.   Most are in the USA and in Europe.  Africa has only one official site.  Antarctica has none.

Maybe Antarctica could help explain some of the strangeness of the data.  The ice sheet in Antarctica has been growing in recent years.  2013 has set one record after another.  The ice sheet is the largest it has been (surface area) since satellite data began in 1979,or so says the National Snow and Ice Data Center.  And they have pictures:

It looks like gravitational forces in Antarctica have been increasing in recent years.  Sea level should be higher near the coast of Antarctica and lower in the middle of the Pacific.  It would help explain why Hawaii’s sea level is increasing less than ….say San Francisco.   Perhaps the amount of ice over land in Antarctica might offset the melting in Greenland .

Antarctica and the Arctic might be offsetting each other.

It doesn’t explain why folks in Australia show a rise in sea level that does not persist in California.  Maybe it will even out some time in the next 30 years or so, one way or the other?

Antarctica’s mass is growing.  That’s my best guess for why some sea level data makes no sense.  That and time.   Much of the data in the NOAA data base is less than 30 years old.   There you have it,  my current best wild ass guess.   Absent field measurements of actual sea level activity near Antarctica…who’s to say I’m wrong.

At least I admit I’m guessing!

Arctic Ice Sheet Growing Rapidly

I have been traveling around Europe since late October.  Alaska greeted me with bone chilling cold as I exited the airport terminal on Sunday.  As I write this blog, the temperature at my house sits at a balmy -7 F (-21 C for everybody but the USA).  It has been cold most of the time I was gone.

This got me wondering about the Arctic Ice Sheet.   So I wondered over to the National Snow and Ice Data Center and took a look.  The Ice sheet is growing at a surprisingly rapid rate.  The site has lots of information about the Polar Ice Cap.

When looking at this data it is helpful if you ignore the 1979-2000 average data presented in grey.  Virtually all summer data in recent years is outside the grey area which is supposed to cover 95% of all data.  The grey data set is an object lessen of poor statistical analysis.   The aforementioned website has an interactive chart with better data that displays averages and standard deviations for the entire data set, but it doesn’t transfer well, so I used this one.

2012 was a big year for summer melt….and so far it has been a big winter for ice building.   Summer data appears to vary wildly, while the winter data is much more stable.  This is likely to continue due the the nature of sea ice.  First year sea ice has a higher salt content than ice that has been in the Arctic for a while.  This higher salt content makes it melt more rapidly than ice that is older. And there’s been lots of first year ice in the data set since 2007.

People searching for benefits of global warming talk about the shorter shipping routes the Arctic represents.   Environmentalist worry about Polar Bear habitat and excess rain and snow in Europe.   Yep, they are going to happen….but you better be quick.  Summer is an extremely short season and winter seems to last forever.

So far at least, the changes seen for most of the year have been relatively small when compared to the wild variation seen in summer.    If and when the Arctic gets a cold summer following a cold winter, then we will have more second year ice…and the ice will become more stable.  But until then the ice will continue to show wild swings in summer.  It really is more a measurement of past warming, and less so a warning flag of future warming.

But is it?  Recent studies argue that yes the ice melts faster when it is warm, but it also is impacted by pollution.  Air pollution discolors the ice, making is slightly less white, which helps it absorb sunlight in summer.   So maybe it’s a marker for air pollution.  Either way first year sea ice is more a marker of past woes and less a predictor of future woes.

If the trend of a warmer more polluted world continues then the summer ice free area will probably expand.   This is not a new experience for the Arctic.   130,000 years ago the Arctic was much warmer than it is today and it is widely believed that there was  less ice then than we have now.    And 20,000 years later it was much colder.

But this analysis is probably too simplistic too.  If the ice free period expands, then snowfall in the Arctic will likely increase too, which could bring on a new ice age cold period.  Or maybe not.

The current climate cycle for the earth is 2.5 million years old.   Any effort to predict long term trends using a 35 year data base is more than a bit speculative.   Talk about wild extrapolation.  It is virtually impossible to identify a trend in a 2.5 million year system using a 35 year data base that is more reactive than predictive.

Well.   What happens next?  I don’t know.   Time will tell.

Arctic Ice Data Set — Too Small to be Useful

I’ve been complaining about the small Arctic Ice data set in recent posts.   Satellites have only been around to measure this stuff since 1979 so a small data set is virtually unavoidable with the knowledge we have today.  I suppose I’m not complaining about the data set…but about the way it is used.

We as a society ( the IPCC and their friends) have been making all sorts of judgements about all sorts of things (Polar Bear habitat is my personal favorite) for years now…by relying on small data base sets and extrapolation.

I have never been a fan of extrapolation.   When a 32 year data base is extrapolated for hundreds of years….I get nervous.

Allow me to explain.  Let’s begin by looking at the University of East Anglia UK global temperature history going back to 1850.  Still a small data set, but a bit better than 32 years.   I prefer East Anglia data to NASA data as a previous post discusses.

The period of most rapid change in this graph is the period from about 1977 to 1998.   Since 1998 it has stabilized at a new higher temperature and has been cooling slightly in recent years.   Any data set that uses the period from 1979 to 2000 as a baseline is ignoring recent data.  That very small data set is going to generate odd predictions.

Unfortunately, that is exactly what the University of Colorado does every day at their web site on Arctic Sea Ice.  Here is a map showing changes in sea ice in 2010 and 2012….and also showing an average (median)  amount for the period 1979 to 2000.

I wonder what the ice sheet looked line in ….say 1942 or perhaps 1912.  1942 was at the end of a 30 year warming cycle and 1912 was at the end of a cooling cycle that appears to have begun in about 1879 according to East Anglia University data.  Can we really predict anything with certainty about ice melting patterns in a climate system with this much natural temperature variation….particularly by extrapolating small data sets?

Arctic Ice Data

Several months ago I began following the data presented at the National Snow and Ice Data Center.  The University of Colorado provides the web site.  I really like the site, it’s full of interesting information and is less preachy than many climate data sites.

In April, the Ice Sheet in the Arctic was above average, now it’s at record lows.  Two months of very good ice formation weather was followed by two months of really good melting weather.  What conclusions can be drawn from the data.

Not much.  The data set is too small.   If we can go from above average to record lows in just 3 months…and most of the data in the last 5 years  lies outside  + or – 2 standard deviations (that should hold about 95% of the data) …the data set probably is too small.

The data appears to be fluctuating more than statistical analysis says would be normal…either the data is very unusual, which means the world is changing rapidly or the base line data is skewed.   I vote for skewed data, but I don’t know and I worry about air pollution coming from China.  Increased carbon dioxide in the atmosphere and/or increased particulate air pollution from China might be really messing things up.

Most of the recent data is outside the normal data range.  I suspect the normal data range is flawed.  Time will tell…..lots of time.  Don’t expect an answer next week or next month or next year.  We could still be trying to figure this out 10 or 20 or 50 years from now.

Arctic Sea Ice Grew in March

The Arctic ice cap has stopped growing and started melting.

March was a good month for ice in the Arctic.  Arctic sea ice peaked on March 18 and March added a total of 54,000 square miles during the month.  2012 had the 9th lowest March in the 34 year record.  February of 2012 was the 5th lowest  February in the record…so March really did well ….if you like Arctic Ice.  Interestingly, March is normally (if anything can be called normal with only a 34 year history) a melting month.

The following graph was prepared by the National Snow and Ice Data Center, which can be accessed through the following link

http://nsidc.org/arcticseaicenews/

Conventional wisdom of 1975 stated that the Arctic Ice Sheet was growing rapidly.  Data that begins in 1979 does not show 30 years of ice growth from the 1940’s to the 1970’s and that must be taken into consideration when evaluating this rather small data set.

The Arctic was cold in March this year, and the Eastern USA wasn’t.   Interesting, but not surprising….we all must resist the temptation to draw worldwide conclusions from regional data.

Yes there is more ice, but the ice is thinner than in past years and much of it is first year ice…so we could see it all melt rather quickly.

Fresh water freezes before salt water.   As sea ice freezes, the initial ice has less salt than the ocean.  A salt rich liquid is formed in lenses throughout the ice.  As the ice continues to freeze, the liquid remaining becomes saltier and saltier.    When Spring comes, the salty lenses are released into the ocean and replaced with the much less salty sea water.  If the remaining ice lasts through the summer it becomes second year sea ice. Second year ice has less salt content, is stronger and it melts more slowly.

When the Arctic has a very warm summer as it did in 2007, it takes at least 2 cold years to recover that ice because of the way sea ice is created.

World climate is very complicated, and just about everybody simplifies it too much.  I don’t know what will happen next…but as a person that lives in a northern climate…I really don’t want the ice cap to get bigger.  So a rapidly expanding ice cap isn’t necessarily a source for celebration for me.

World leaders met in Copenhagen in December of 2009.  The UN wanted  to extend the Kyoto treaty that is set to expire at the end of 2012.  When those meetings failed to produce an agreement, Al Gore predicted the Arctic Ice Cap would be gone in the summer in 5 years and global carbon dioxide levels would accelerate.   So far at least, he has been wrong.

I like seeing Al Gore proven wrong…but I don’t really want a colder world…so I am of two minds.   I am confident Al Gore is a big time wild ass guesser, and I would like the world to stay nice and toasty…as long as it doesn’t warm too much.

A growing ice cap may be good for polar bears, or maybe not…but I know it’s not good for me.