Hi G-W

We will know soon enough, I think.

Since the maximum on March 9th we've had three periods of decline so far, interspersed with some brief recovery. Based on the years since 2003 we are in the period now where increases are very rare and mostly marginal. Equally the rate of decline accelerates and daily losses around 50k are common.

Yep we're approaching the time of year when the year-to-year variability is very low, so even less can be read into the little ups and downs. Looking at the graphs it's only by around June at the earliest that the trajectory of the ice loss has any real bearing on September's minimum.

Maybe, Stu.

We are still within 250k sq km of the lowest value at this point in the cycle since 2002 and 1.7m down on the 1979-2000 mean.   If we have even an average melt season (9.0m sq km) we will be 2nd or 3rd lowest again and a melt similar to 3 of the last 4 years would put us close to breaking the 2007 4.25m level.

http://nsidc.org/arcticseaicenews/2011/040511.html

Very interesting?

The Guardian's report on the research about the increasing freshwater in the Arctic -

A vast expanse of freshwater in the midst of the Arctic Ocean is set to wreak unpredictable changes on the climate in Europe and North America, new scientific analysis has shown.

The water – comprising meltwater from the ice cap and run off from rivers – is at least twice the volume of Lake Victoria in Africa, and is continuing to grow. At some point huge quantities of this water are likely to flush out of the Arctic Ocean and into the Atlantic, which could have significant impacts on the climate. Scientists say they cannot predict when this will happen though.

"This could have an influence on ocean circulation," said Benjamin Rabe of the Alfred Wengener Institute. "It could have an influence on the Gulf Stream."

and.......

http://www.guardian.co.uk/environment/2011/apr/05/arctic-ocean-freshwater-climate

I'm more concerned with the immediate impacts that the Arctic Amplification is having on our atmospheric circulation myself. The changes that 'could' occur due to freshening of the north Atlantic will not have too great an impact on the N.A.D. as it's 'motion', across the Atlantic, is augmented by it's atmospheric impacts on the Western seaboard of the U.S. (drifting it our way).

http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent_L.png

We have now turned the corner into melt season proper (no 'balancing act' from now on with losses matching gains) and we await our first 100k loss day (we've had a 160k over 2 days a few days back).

Hi Gray-Wolf

I don't think your comment about the NAD is correct.  Firstly I wonder how much the wind influences or drives the current - very little I would think. Secondly, even if the wind did maintain some sort of flow, it would be much less warm water if the ocean conveyor was weaker or turned off.

As we keep repeating, the global climate system is highly complex, full of interdependencies and has non-linear responses to changes in inputs.  This news is just such an example, i.e. a gradual build up over years of fresh water in the Arctic basin followed potentially by a tipping point if it spills out into the Atlantic and disrupts the sink mechanism upon which the thermohaline circulation depends.

Losses of 100k or more in a day are actually exceedingly rare in April and rare May.

Taking April and May since 2003:

2003:  April - 0,  May - 0

2004: 2 & 2

2005: 0 & 0

2006: 1 & 2

2007: 0 & 0

2008: 1 & 1

2009: 0 & 1

2010: 0 & 3

So, over 8 years only 4 occasions (out of 240) in April and 9 (out of 248) in May.

New warning on Arctic ice melt

Scientists who predicted a few years ago that Arctic summers could be ice-free by 2013 now say summer ice will probably be gone within this decade.

http://www.bbc.co.uk/news/science-environment-13002706

Original ice-loss predictions were for an ice free summer some time around mid-century. I still consider that a possibility, but also possible is that the ice will detstabilise and sometime in the next 10-20 years it goes kaput. I give that latter viewpoint much more credence given that ice hasn't really had a recovery to speak of since 2007's extreme loss.

It really doesn't surprise me that they've pushed the prediction back from 2013 though.

It will depend to an extent on the definition of 'ice free'. If this means no solid ice area then that is obviously more likely than nothing above 15% coverage (the current definition for 'ice extent'). Completely free of ice seems unlikely in the near future.

As I said on my blog this morning with regards this "Reading between the lines, I think what Wieslaw Maslowski is really saying is that we shouldn't assume that it'll not be until at least 2040 before we see an ice free Arctic - it could happen sooner, perhaps as soon as 2019. Which is not the same as saying it will!"

(the media, of course will always misquote out of context and dumb down the message in order to provide a more sensational headline - though some so-called climate sceptics still naively trust every word they read, and will no doubt totally get it wrong. Again)

All these predictions seem to think trends can only ever go one way.
The natural world has a way of making them seem like idiots.
The mechanisms causing ice volumes to change are not really understood as well as some like to claim.

Nope. They think if forcings are going one way then that is the way they are going.

See you in ten years...

How do you know?

Well obviously if Yellowstone erupts, all bets are off!

But at the moment there is no reason to suppose current trends will reverse any time soon.

You are absolutely right - the natural world has natural patterns and cycles.  The difficulty comes when unnatural forcings are bing injected into the system.

As for ice volumes - it is extremely well understood.  You have melting from below due to warmer water, melting form above due to warmer air and transport of ice out of the Arctic Basin due to the thinning and break-up of the ice.  Of course the specifics are not clear but the general mechanisms quite clearly are.

All these predictions seem to think trends can only ever go one way.
The natural world has a way of making them seem like idiots.
The mechanisms causing ice volumes to change are not really understood as well as some like to claim.

Originally Posted by: Solar Cycles 

You are absolutely right - the natural world has natural patterns and cycles.  The difficulty comes when unnatural forcings are bing injected into the system.

As for ice volumes - it is extremely well understood.  You have melting from below due to warmer water, melting form above due to warmer air and transport of ice out of the Arctic Basin due to the thinning and break-up of the ice.  Of course the specifics are not clear but the general mechanisms quite clearly are.

Originally Posted by: Gandalf The White 

You missed out "ASSUMED" un-natural forcings Gandalf, It's just as well I pop in here from time to time, otherwise all sorts of ASSUMPTIONS would be made! 

Originally Posted by: four 

What would we do without your eagle eye, SC

I have just re-read my post and I don't think I missed out anything. 

You have a decision to make - are you going to declare yourself as a denialist or a sceptic?  If seriously you are going to imply that there are no proven forcings at work then you are now in the denialist camp - I am assuming that it cannot be lack of understanding from some of your previous contributions.

If you think there is nothing unusual going on then please provide a sound explanation for:

Average daily ice extent:

1979-2000:  11.98 million sq km

2003-2010:  10.39

Natural, cyclical changes in ocean and atmospheric circulation?

Such as?

We've been here before.  Anyone can throw such comments into the ring but they are just smoke and mirrors.

Look at the thread I started about further research into the Arctic climate in the past.

CO2 pushing towards 400 ppm.  Nothing of that level in the past 800,000 years.  Which natural cycle is making this happen I wonder?

I've read something on the first page on the site you've indicated on your other thread?

.Maybey it has something to do with ratings or dates?.Perhaps.

It appears, old research that turns out to be faulty can be swept under the carpet and corrected as a mere mistaken model.

Could this be another case forth comming?.

Maslowski et al.as mentioned earlier on this thread comes to mind on that point.

Are you certain about 800,000 years.The headline is 15 million.

Who is Tripati?.

Link below.BTW.Mouse over to access.

Last time carbon dioxide levels were this high: 15 million years ago, scientists report Oct 08, 2009 | not rated yet | 0

I would also be interested in any peer reviewed papers released on the subject in question by Tripati?.

A dead end if you ask me.

I am surprised at you for posting such rubbish.Gandalf.

Been on the Guinness again AIMSIR?

I think my friend that you miss the point.  It doesn't matter whether it is 800,000 years or 1 million or 10 million.  The point is that we are altering the atmosphere in a significant way and there are and will be consequences.

Sometimes you can miss the wood for the trees.

Sea ice extent seems to be lingering on a crest this year.

Any ideas as to why?.Anybody.

No it isn't - if you look at the figures you will see that we are almost 500k sq km down on ice extent compared with the peak one month ago (and over 300k in the last 7 days).  The decline is proceeding apace.