How is the Arctic Sea Ice doing? Is there a ‘recovery’ in sight?
Yes.
That’s because this is the time of year when the sea ice level recovers. It’s now (using CT’s figures) about 1.585 Million km2 below the long-term average for this time of year. Eyeballing the NSIDC daily update graph gives about -1 million for their metric.
Loooking at the normal range of the anomaly (excepting the last couple of years), I’d guess that we’re likely to see the sea ice level ‘recover’ to about a million km2 below long-term averages by the end of the season (March). In previous comments on the other post about sea ice, I suggested that, if the Winter Max. falls between -0.7 and -1.0 Mkm2, then by the end of next melt season, the odds are strongly in favour of the minimum being closer to 2007 and 2008 than to the preceding decades; in other words, an anomaly of 2 Mkm2 or worse by September 2009.
So, don’t start thinking that the long-term (or short term) prognosis for the state of the Arctic is improving; the patient is still critical, and any talk of an improvement in condition must be understood to be relative.
🙂
Old man in a cave 
8 comments
Comments feed for this article
October 23, 2008 at 9:44 pm
Iain Hall
Fergus
How can you talk about “long term averages” for sea Ice extent when we do not have comparable data for the extent of sea ice prior too the advent of satellite imaginary?
Or are you claiming that about thirty years of datat is sufficent to make such claims?
October 24, 2008 at 8:27 am
fergusbrown
Hi Iain and thanks for visiting.
In this post I am using ‘long-term average’ as shorthand for ‘the 1979-2000 average’, which is the standard used by the teams working on this.
Of course there is a long-term dataset but, as you hint at, the uncertainty prior to 1979 is quite high. One of the reasons that sea ice has different measurements (area and extent) is to maintain the historic dataset for comparative purposes. I am satisfied that if this is good enough for the NSIDC and NOAA, it’s good enough for the rest of us.
The implication of your comment is that there is some doubt about the relative amounts of ice in the Arctic compared to previous decades. Accepting the limitations of the data as mentioned above, I presume you have some justification for this doubt; please will you share it with us. I have no doubt that Bob and Walt and the others will be interested to learn of something they have missed.
in anticipation…
October 24, 2008 at 8:47 am
Iain Hall
To be entirely Frank Furgus I think that in climate terms saying that data from 1979 until now is hardly long term, my interest in this topic goes back to the recent claims that the Arctic ice was at the lowest level for centuries but as you concede we do not have sufficient data to make any such claims prior to 1979. and there is anecdotal evidence that sea ice was as low in the 1930’s as it was at the end of summer this year.
October 24, 2008 at 3:59 pm
fergusbrown
Iain, can you provide me with a reference for the claim that sea ice was at its lowest for centuries? If it comes from a reputable source, then I’ll accept it; if it comes from media speculation, I’ll be looking for the spin.
I did not concede that we don’t have sufficient data; I said that there was uncertainty in the historic dataset; this is different.
There may be anecdotal evidence that sea ice levels were very low in the 1930’s, but I’ll take observational evidence over anecdotal any time.
Can I suggest you read a history of the North-West Passage, perhaps, to get a sense of what, for example, the Franklin Expedition had to deal with, and then compare that with 2007.
My interest in this topic goes back thirty years, but my knowledge base only started to increase about two years ago, when I went out and read the science that was available at the time. I’ve been keeping an eye on it since. Can I recommend the same for any reader of this blog?
November 2, 2008 at 7:32 pm
Jon
Hi Fergus, it’s just over a week since you made the prediction that the “recovery” would get to -1m sq km by March. It has very nearly reached that target already.
With the extent so far ahead of the area and SST’s looking pretty low in several areas of the remaining open water I suspect the rise will continue quickly for a few more weeks yet.
Of course it is still too early to tell where it will finally finish up but I think it will beat your upper value of -0.7m sq km and I would not be surprised to see it get close to 0 or above.
November 3, 2008 at 2:46 pm
fergusbrown
Hi Jon and thanks for commenting.
It sounds like you are expecting the ‘recovery’ (ie, the reduction of the anomaly) to continue in a linear or near linear manner. Most recently, the sea ice has ‘recovered’ within the range of historic patterns. That recovery has sort of flatlined now.
I am basing my estimate (guess) on my understanding of the data and trends, which is limited, but am still inclined towards the view that the range of anomaly cited in the post is the most likely.
During the coming months, the anomaly may well go below -0.5, perhaps even -0.3 in occasional ‘peaks’, but by the end of the season, when the sea ice reaches its maximum, I anticipate it following recent trends.
Since there hasn’t been a positive anomaly since 2003, I would be surprised if the March anomaly was even close to 0.
Regards,
November 21, 2008 at 2:04 pm
Rob
I hope now that the suns energy, sunspot count is almost zero and the 30 year PDO has reversed to its cooling phase the 1979 to 2000 average will continue to be used by the warmers. I have a feeling that if the ice continues to approach the levels of that average there will be new papers published that find the average somewhat lower, we will see.
What stands out to me is that historical and archaeological evidence is discounted by the warmers in preference to climate models and cherry picking dates.
November 23, 2008 at 9:21 am
fergusbrown
Hi, Rob.
You will find reference to ‘all the historical and archaeological evidence’ in the AR4. Indeed, one of the points of the AR4 was to provide an assessment based on the evidence. Without the historical datasets, it would be impossible to operate climate models effectively. Without the ‘archaeological’ (palaeo?) ‘evidence’, we would be hard pressed to offer a sensible assessment of present conditions and the implications of warming.
What you are saying, then, is a standard reversal of fact; the conclusions about GW are based on the best and most comprehensive evidence, whereas the denial of GW is often founded on cherry picked datasets and unsound science (or even non-science).
Why do you fins it so difficult to accept what is blindingly obvious?
You might find my forthcoming entry interesting.
regards,