Arctic sea ice has been in the media quite a bit this month and we looked at the issue in a blog a couple of weeks ago.
Late last week there was an update to the continuing story, as the National Snow and Ice Data Center (NSIDC) in the US announced that Arctic sea ice extent had reached its summer minimum.
Figures from the NSIDC show this year extent fell to 5.10 million square kilometres on 13 September, and the ice cover is now increasing as we head into the northern hemisphere winter.
It’s possible that a shift in wind patterns or a late season melt could push ice extent lower, but – assuming the current figure remains – this year’s minimum extent is the sixth smallest since satellite records began in late 1970s.
The five lower seasonal minimum ice extents all happened from 2007 onwards, with the record set last year. That record low was just 3.41 million square kilometres, a notably low figure that was likely to have been influenced by weather conditions over the region which accelerated ice loss.
While a detailed analysis is required to understand the exact causes of the seasonal minimum this year, the weather conditions during the summer have been less conducive to ice loss than those experienced last year.
From late May to late June a stream of storms entered the Arctic Ocean, creating cloudy conditions at the time when the sun was at its strongest.
Relatively high ice cover during June and July (compared to recent years) was likely to have delayed the warming of the upper ocean and reduced melting at the base of the ice towards the end of the melt season.
We do expect a year to year variability in sea ice extent precisely because it can be so heavily influenced by weather patterns, but there is a long-term picture of decline – as you can see in the graph of August ice extents below.
New ice thickness data from the Cryosat satellite has also been released recently, and this shows a continuing shrinkage of winter ice volume. This provides a timely reminder that despite the modest recovery in seasonal minimum ice extent this year, the ice continues to thin and the volume of sea ice continues to shrink.
The evidence continues to pile up that industrial society is changing our climate, and that we are running an experiment whilst being subjects of that experiment; future generations will shake their heads and wonder what the hell was wrong with us.
On the other hand future generations may think you have been easily fooled.
Changing the goal posts once more. If extent doesn’t matter then go for volume. As was said before a thin layer of ice is easier to melt. But it hasn’t melted. Has it?
There is enough ice this year to keep the North West Passage closed despite the highest “forcing ever from CO2” concentrations.
Why not give us the low down on Antarctic sea ice? Global warming is global not regional right.
And
Let people make up there own minds about the state of the globe.
Plus, the Met has already reported that the Atlantic multi decadal oscillation has been in positive phase until lately. NOAA state that this natural oscillation has endured for more than a thousand years. Surely the positive phase of the North Atlantic “natural” oscillation of around +0.6 of a degree flowing under the Arctic ties in with recent trending.
A balanced report would point out that Antarctic ice extent is also breaking records, that the satellite era is too short to form any conclusions with evidence that there were similar fluctuations in he 30’s and Greenland was settled for 200 years during the medieval warm period but we have long since given up on expecting balanced reporting from the Met Office.
Yet another one sided article from the Met Office. Now that Arctic sea ice has made a remarkable recovery in 2013 we are presented with spin about ice volume. What’s the Met Office going to do next year when the extent and volume increases? I suppose an attempt will be made to find another metric to disguise the ‘problem’.
In any case, half the story is missing from this article. Where’s the real story, the fact that the Antarctic sea ice extent has reached another new high since satellite records began in the late 1970’s. I can only conclude this is because the good news merits an article all of its own. Or is that just wishful thinking.
Clearly, it was just wishful thinking.