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

Let's hope we are not starting the year as we mean to go on?????

Extent, area and volume are all different measures.

Extent is the area covered with ice to more than a certain concentration (usually 15% or 30% but the source should specify). By definition it therefore includes some open water.

Area is the best estimate to exclude open water and include only ice. IIRC if the concentration is less than 15% the area can't really be calculated - so neither meaure includes really spread out ice cover.

Volume does what it says on the tin.

Finally, ice cores are from ice sheets on land, not sea ice. Either way, the amount of air trapped in the ice is miniscule compared to how much air is in the atmosphere

Interesting insight into Arctic ice melt as well as other aspects of climate change, although on initial reading the author isn't upto date with regard to ocean temperatures.

The threads on winter NH 'snow cover' and the 'strange jetstream forecasts'are also relevant.

This imo, is good 'holistic' climate science - something to build on, because imo, as written/reported here there are some aspects which are contradictory - present ocean temperatues for example and which would imply another driver with credence - the quiet sun, is involved too.

see -

http://www.nytimes.com/2010/12/26/opinion/26cohen.html?_r=3

Note - I have posted in the three threads as the article is 'holistic' climate science

Hi Caz, I'm just catching up with this thread.

That graph, to which you referred, is showing anomalies and the low value was in September 2007, at the end of that summer's record melt season.  That produced the record negative anomaly at that point in the year.

The chart that shows the rise and fall of the Arctic ice extent is a better indicator of the pattern and trends (when the graph shows multiple years and, ideally, a 30-year mean as well).  Extent and area give a similar picture, based on my occasional comparison of the two charts.

The volume chart is, of course, the best measure of the overall health (or otherwise) of the Arctic ice.  It tells the same story of steady decline.

I am really puzzled by SEMerc's comments - the data tells a very clear story of long-term and steady decline.  I commented a few pages ago that the argument about recent synoptics being remotely relevant was wrong - As I said before, when the cold was bottled up in the Arctic by the strong jet the ice was melting and now that the cold is anything but bottled up in the Arctic the ice is melting.  The synoptics are irrelevant to what is clearly a climatic shift in the Arctic, i.e. this is most definitely now about climate and not weather.

I agree that arctic sea ice will continue to reduce regardless of synoptics, but particular types of synoptic pattern do appear to accelerate the reduction (or slow the refreeze) more than would be expected from the trend.

If it is about climate, it is more likely to be ocean currents affecting the amount of Artic Ice, rather than not. Ocean temperatures and currents, particularly away from the Tropics, reflect climate from the past - the oceans store heat in periods of warming and release it in periods of cooling. We are now entering a decade of cooling and in time that will begin to affect the Artic and ice extents will gradually increase from where they are now.

It would be interesting to see what the annual totals of sea ice are.  2007 was a bad year during Autumn with an all time low, but recovered by winter and into the following year. December 2010 figures are at a new low, whilst April/May 2010 were at a new high.  None of the years shown have sustained an all time low or all time high.

8' and 09' are difficult years to access I believe. The phenomena that prof Barber witnessed in the south Beaufort sea was most probably widespread in areas with Paleocrystic ice so talk of 'recovery' when a portion of that years ice extent was due to  collapsing/slumping ice.

The final demise of all but a small amount of the remainder of the Paleocrystic last summer means that we will not be troubled by this any more though.

EDIT:

http://nsidc.org/arcticseaicenews/

Latest from NSIDC. Seems now that the old 'nurturing' weather patterns also destroy ice? As I have pointed out the 'winds' that used to compress/build ice along the north coast of Greenland/Canadian Archipelago now flushes it out via Fram.

that's confident of you - do you have a crystal ball

Any cooling this next decade will probably only be regional rather than global. It is possible that the UK may cool in both winter and summer due to solar effects, but this will have no cooling effect on the arctic.

2011 will almost certainly be cooler globally than 2010 due to La Nina, but the 2010 global temperature is likely to be attained again during the next El Nino provided it is of at least moderate strength.

Currently the rate of increase in temperatures in the arctic exceeds the global rate, and the evidence suggests this will continue to be the case for the next decade. Realistically ice volume in the arctic can only go one way this next decade, and that is downwards.

No, but it is my belief, having looked at what happened in previous periods when solar activity was very low.

Of course, many would say the goal posts have moved since the LIA and the Dalton Minimum as a consequence of AGW, but I would beg to differ. That is not to say that AGW is a wrong theory or that global warming will not occur, but I see it as very much a background, slow burner. In the meantime, the PDO is negative, the AMO is due to go negative and we have a very weak solar cycle or two to look forward to. In the coming 10 to 20 years, it all adds up to cooling being the overriding signature, rather than warming.

Of course, once solar activity picks up again and the PDO turns positive, AGW will be back with a vengeance.

Isn't solar activity higher now than it was in 2007, 2008 and 2009 or am i reading the graph below wrong?

Solar Activity has picked up from the rock bottom minimum levels of the past few years, but by now it should be rocketing up the scale. That it is not, indicates a very weak solar cycle - probably equivalent to SC4 and SC5 during the Dalton Minimum. At current levels of activity, there is little effect - this is a remarkably extended minimum.

Sorry, I don't understand how we can be entering a decade of cooling because of weak solar activity when that has been in place for the last 3 to 4 years. Last year was the 2nd warmest on record.

I have been doing a little digging around the Internet to look at past cyles and comparing with the CET values.

The last time we were close to this current depressed level of sunspots was the beginning of the 19th century, when we had a maximum of around 50, followed by two cycles of around 100.

http://en.wikipedia.org/wiki/File:Sunspot_Numbers.png

The CET values for the first decades of the 19th century show no evidence of any significant cooling, although the winter of 1814 showed a mean of 0.4C, which is the fourth coldest in the record since 1684.

So, I'm not convinced that even with the lower values in the current cycles, that the CET will show a marked drop - but who knows in the post-modern winter....

I have updated my record of Arctic ice extent for 2010 and the average of the daily values came in at 10.232 million sq km.

That value is lower than either 2008 or 2009 and only silightly ahead of 2006.  2007 remains the lowest year at 9.964 million.

If we see a strong continuing build of ice for the next three months (as we have in the last three years) then the maximum should just exceed 14.0 million sq km again, just above the record low of 2006 (13.78m). 

If we see only average growth from here (which used to be 1.3m added from here) then we are at risk of being near a new low come end of March.

The Danes seem a bit concerned about the Greenland ice cap

http://politiken.dk/newsinenglish/ECE1161570/greenland-close-to-unavoidable-meltdown/

Yet more confirmation that we are having a serious adverse effect on the planet.  Not only that but it is clear from this and other evidence that there are risks that the impacts of global warming could indeed be worse than the predictions.

No doubt the usual sceptics will appear and argue this is either normal or due to natural factors....

For those interested in the extent of the Arctic Ice, another drop yesterday and another date record low...

12,361k yesterday - 2.2 million sq km below the 1979-2000 average.

When I look at what is happening I understand that my 'world view' is very Lovelokian and so when I see 'tipping points' being breached (as with the Arctic Sea ice) I know that other 'tipping point's' will fall soon after.

The first 'tipping' points cost the 'energy budget' most but thereafter the addition of both those points 'tipped' and the 'extra energy' freed up in the energy budget makes the other breaches easier and easier to to tip.

The 'Arctic Amplification' is the first impact we in the Northern Hemisphere is truely feeling but this massive 'switch' in n.Hemisphere circulation (over the first part of winter) 'knocks on' to other systems further south and these peturbations eventually 'feed back' to the Arctic.

Let us see whether summer extends beyond late June this year? (here and N. Pole) as we may be in for a nasty shock in 'ice extent' this summer (if record lows continue up there) with an 'average summer' taking us below 07's record low and a 'perfect storm' summer costing us the difference between that and a  'seasonal pack'.

The primary driver for the amplified pattern in December was most likely solar. I have explained previously why it is inconceivable that the primary driver was the low sea ice.

The trend in arctic sea ice will remain downwards this coming decade regardless of synoptics, but I suspect the current record breaking levels (ie low for the time of year) are at least partly caused by the amplified pattern.

So it makes no difference how much self flagellation is indulged in then?