You are currently browsing the category archive for the ‘Sea Ice’ category.
This newish paper in The Cryosphere, by Sole et.al., seems to be a decent stab at analysing mass balance changes in the Greenland Ice Sheet and suggesting an explanation.
By their calculations, marine terminating glaciers are thinning much faster than land terminating ones. But they are, mostly, definitely thinning; this should come as no surprise to readers of the literature.
Their broad conclusion is that recent changes in the GrIS probably have most to do with changes in the surrounding ocean conditions. One of the more interesting suggestions they make is that, once marine terminating glaciers lose contact with their outlets (shame there’s no timeframe), the GrIS is unlikely to contribute much to sea level rise (sort of obvious, but worth noting).
Skumtics needn’t bother atarting to infer anything from this: the GrIS contribution to sea level rise is small, and anyway, sea level rise, in spite of the attention of the media, is not likely to be the most significant consequence of climate change. For this, I’d suggest drought and famine are likeliest contenders, closely followed by political instability and climate migration.
Good to see Stoat staying on the case: I think I probably share his POV on this subject, with less scientific basis. Note, following the comments I made in response to the posts by Antony Watts, that current sea ice anomaly is around -1 million km2; I’m optimistic that my predictions back then might be cashed in by March.
I’m currently framing a bet I would be willing to put money on. More later when I have done so.
Finally, thank you to all 41000 viewers who, by accident or design, have hit my page. Given my lowly estate and somewhat inconsistent blogging habits, it’s more than I ever imagined. I hope of you have got something from these pages. Best wishes :)
How is the Arctic Sea Ice doing? Is there a ‘recovery’ in sight?
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.
The Old Man was looking at recent conditions to try for a prediction of next year’s sea ice minimum. More on this shortly; during the research, what came up was the ENSO. It’s neutral at the moment, predicted to be for the next six months. But an eyeball of the Pacific SSTAs raised a question about the direction and strength of the ocean currents, and the direction and strength of SSTAs.
I don’t know if these two are directly linked, but I imagine they are. If this is correct, then it seems reasonable to predict, this far out, that we could be in for a very strong El Nino, starting late in 2009 and continuing for at least two years.
This is mainly based on an interpretation of the 2008 Sea surface temperature anomaly pattern in the Pacific and its relation to ocean current direction and the ENSO area. There is a moderately strong positive anomaly in the Southern part of the West Pacific, stretching along the line of the current in that part of the Ocean, and apparently heading towards South America. There is a huge positive anomaly in the North Western sector, which should be associated with the North Pacific current, which heads towards the US west coast.
On an eyeball analysis, the pattern of Pacific SSTA is a broad clockwise motion in the Nothern hemisphere, and a broad counter-clockwise motion in the Souther Hemisphere. Thus, currents move across the equatorial region from the Americas to Japan (yes, there’s also an equatorial counter-current), go round in a big loop to North and South, and come round the American coasts and back towards the Equatorial region, where ENSO is formed.
There’s vertical mixing to take into account, as well as the flow between the Atlantic and Pacific, but this latter I suspect is a longer-term relationship (which would still, nonetheless, likely exhibit a positive anomaly). There’s a very good chance that a half-competent oceanographer will be able to explain what I’ve overlooked, and that this projection/prediction is nonsense.
Given the trend in global surface temperatures, the current state of NH snow and ice cover, recent ENSO trends and the generally warm oceans, and since my reputation or career is not on the line, I am now going to say that we are probably heading for a monstrous El Nino, starting either late 2009 or early 2010. Why does this matter?
Back to the sea ice. The Old Man’s mind isn’t entirely made up about the forthcoming melt season, though early indicators are that this Winter will be mild in the NH and snow cover (hence albedo) will continue to be well below average. At the moment, the feeling is that there is a chance that 2009’s summer melt will exceed the record set in 2007, but the analysis is ongoing. In the longer term, though, if (big, big if) we get an El Nino in ’09, then 2010 will almost certainly beat 2007. If we have a strong continuing El Nino through 2009 and 2010, then there is a chance that the Arctic Ocean will be effectively ice free (except along the North Greenland coast) in the Summer of 2011.
Definitely want feedback from scientists on this one…
Edit: There’s a technical description of the recent trends in sea ice loss here: no mention of the El Nino, but the Search/ARCUS summary of 2008 suggests that the current condition will continue until a new warm season triggers another stage of decline.
I was rude to Antony Watts a while back for misinterpreting the differences between different Arctic Ice measurements. Now, I am going to praise him. Well done to you, whom I know as a ‘climate skeptic’ (though not the wing-nut variety), for following through on the suggestion and contacting Walt Meier. Even better done to publish his responses, in full, on your blog.
Walt Meier is someone who took the trouble in the past to answer my own questions on sea ice, in the era before I dreamed of blogging, and he is, without doubt, a gentleman as well as a scholar of distinction. His work on the Cryosphere is literally world-class, and his patience in addressing the questions put to him on Watts’ blog is remarkable.
But I am not convinced, Mr Watts, that you are quite up to the mark on the issue of sea ice. This isn’t to say that I think I am an expert (am not), but your coverage of the ‘recovery’ as being ‘reassuring’ doesn’t seem to make much sense. The graphics to which the posts refer show recent sea ice development pretty much in line with the expected pattern, yet the underlying implication is that the current season’s recovery is in some way significant as an indicator that the long-term decline of the Arctic sea-ice is less serious than Dr. Meier’s responses clearly state.
Of course I respect your right to your own take on climate change and your own opinion on these matters, but I can’t help feeling that you’ve published Walt’s answers without reading them, or perhaps without understanding them. Maybe you simply don’t want to acknowledge them or the possibility of them being correct; I don’t know. But Meier has a long and distinguished career in the field, and a rational, dispassionate observer might, if required, conclude that the more credible witness in this matter is the specialist rathert than the commentator.
When I developed my own interest in the field, one place I found most useful was the open-access, peer-reviewed journal The Cryosphere . The paper under discussion are also of great value. Unlike the commenters on William’s blog, who seem to think that nobody outside a scientific field reads the journals or the papers, I have read much of this content and, whilst I do not in any way claim expertise, I do think I have a handle on the basics of Cryospheric science, enough to justify a belief that i can comment inteliigently on the subject, if not always accurately. Therefore I commend this short course of reading to your readers, who might as a consequence find many more subjects to question and challenge in the current scientific understanding of the state of the cryosphere.
My praise of you is not false in any way: I genuinely do respect anyone who is willing to publish both their own thoughts and contradictions to it in an open way, as you have. But my concern is also genuine: I still don’t think you have a grasp of the science or the processes.
On a new weather and climate site, Totally weather and climate, someone wrote the comment below to me:I am watching the rise in the arctic ice very carefully as I think it really does resememble watching the signals from a life support machine. If we see significantly higher ice levels this time next year a lot more people will be asking a lot more questions. Two years in a row and possible will have become probable. It woul dbe interesting to see all of the explanations.I live in hope.
To which I replied:
As a student of Arctic sea ice conditions, I’d advise caution over this approach. The interannual variability is huge and the signal-noise ratio small. There is only so much we can garner from any one or two seasons of watching.
As I said elsewhere, climate change needs thinking of on longer timescales to be meaningful.
Take 2008’s melt season, now apparently over; it was slightly less than record-breaking, but not by much. If there was a surprise in ice conditions this year, it was the rate of recovery over the Winter, followed by the relatively slow start to the melt season, which was probably unexpected.
Are we likely to see significantly higher ice levels (I presume here you mean the Summer minimum) next year? Given the state of the multi-year ice, I’d say no. But I’d also look at the ENSO predictions for the next six-twelve months, and try to factor this in, too. Then I’d want to look at the AO and factors such as the Bering and Fram inflow/outflow numbers, and the coming seasons’ NH snow cover (Albedo!), the general sea circulation, and areas of potential forcing such as the north Pacific, Labrador and the GIS ridge.
Taking these into account, then looking at the long term trend, a conservative estimate would be that 2009’s melt season is likely to be comparable to 2008’s, with a 25% chance of it becoming like 2007’s, or worse (though 07 and 08 were very similar, in the end).
If people see two consecutive years of summer minima close to the long term average, they might be inclined to speculate whether we really understand enough about the Arctic to use it as a benchmark for GW. Technically, they’d be wrong to do so, though it is easy to see why the temptation is there. Realistically, there is no reason, at the moment, to think that next year will be any better than any one of the last ten, ie, well below the long-term average. My predicion is that the minimum will be exceeded in the first Summer season following the next el-nino, if not before.
I’d be interested to know who agrees/disagrees with my ‘predictions’, and why; am I missing something?