The National Geographic magazine have just noticed a large increase in the Weddell Sea polynya (south of south America) that I brought to your attention earlier last month in an article that I found on the phys.org website. I can confidently predict that the polynya will continue to increase in size till it totally disappears later in the Antarctic summer!
It looks like this Winters maximum sea ice extent has been reached in the Antarctic a little earlier than average. The spot value for the 12th of September was 18.023 million square kilometres was the lowest maximum in the satellite record that started in 1979, but it was a very near thing, because the 2017 figure was just 4,000 square kilometres lower than the previous lowest maximum of September 1986. The sea ice could surge again and prove me a liar, but I got it right with the Arctic minimum, so maybe I’m on some kind of roll (pardon the pun).
Here is the table sorted from lowest to highest on maximum extent (fig 2). Before you ask 1978 is top of the list because the satellite record started on the 26th of October 1978, and the maximum for that year will have occurred a month earlier and been considerably higher than that figure, blame it on the programmer.
I would say on balance that the Antarctic sea ice extent has bounced back extremely well after what was a pretty dreadful start, back on the 1st of March sea ice extent was just 69.8% of the long-term average for that date, on the 12th of September they were back up at 97.4% of the long-term average for that day. This is the latest rather interesting ice extent picture for the Antarctic from the NSIDC (fig 3), which shows another polynya in the Weddell sea similar to the one in the news item I posted earlier this month. Who knows, maybe if that polynya hadn’t opened up, 2017 might not have been the new record low year!
Not one mention of AGW in this item from yesterday’s BBC News.
I noticed this interesting article about polynya on the Phys.org website (you might what to add this to your favourites because it looks a great site) that might interest some of you out there. I was thinking, it’s only because the upwelling of warm water occurs under an ice sheet that we realise that they’re happening at all. They must happen all the time in the worlds oceans, but we just don’t see them, apart I suppose from anomaly charts of very sensitive SST satellite sensor data.
The Independent today has an article entitled ‘Scientists find what they think is largest volcanic region on Earth hidden in Antarctica after student’s idea’ (fig 1). I can’t believe for one moment that this work hasn’t been previously done before by the Americans or the Russians, but apparently it was all the idea of a third-year student at the University of Edinburgh, Max Van Wyk de Vries, that would be a great collective name for the 91 volcanoes that they discovered – the Van Wyk de Vries volcanoes. They found 91 volcanoes which range in height from 100 m to 3,850 m in a massive region known as the West Antarctic Rift System.
I had to take exception with the bit that Paul Ward has written, because with a story like this there just has to be a link to AGW no matter how weak:
Previous studies have suggested that volcanic activity may have occurred in the region during warmer periods and could increase if Antarctica’s ice thins in a warming climate.
I don’t know about the reference to a previous study he carelessly throws into the article, but what it (or he) is suggesting is that if the ice cap begins to thin a little, this could encourage the dormant volcanoes to reawaken. I am no geologist, or volcanologist come to that, but I find it hard to believe that these volcanoes were effectively plugged by an icecap that formed on top of them, and that they’ll suddenly spring back into life if ever the icecap starts to thin. Surely it’s got more to do with what’s going on under the mantle, and the tectonic forces that are at play, rather than waiting for the icecap to thin? I imagine that volcanoes would have no problem finding the ir way to the surface, despite being sat under an icecap which is 4 km thick in places, isn’t that what recently happened in Iceland with the Vatnajökull volcano.
That just leaves one important question as far as I’m concerned, and that is, what are all the scientists in the many Antarctic ice stations that the nations who have staked a claim to their piece of Antarctica actually doing with their time?
I saw this on the BBC and thought you should see it:
A year in ozone over the South Pole – http://www.bbc.co.uk/news/science-environment-40878910
The BBC article about algae reducing the albedo of snow, reminded me about an article about a similar thing happening that was caused by soot particles, particularly from coal power stations and flare stacks at gas terminals. The Guardian article ran an article about it in December 2016 which said:-
World leaders should redouble efforts to cut soot emissions because it is the cheapest and fastest way to combat climate change, climate scientists and advocates have told the Guardian.
Deposits of soot – unburned carbon particles – have stained parts of the Arctic black, changing the ice from a reflector of sunlight to an absorber of heat, and accelerating the melting of ice and snow, which itself is starting to alter global weather patterns.
A BBC news article says that Scientists are “very worried” that the melting of the Greenland ice sheet could accelerate and raise sea levels more than expected. They say warmer conditions are encouraging algae to grow and darken the surface. Dark ice absorbs more solar radiation than clean white ice so warms up and melts more rapidly. Read more here.
The Arctic sea ice extents still doesn’t seem to be following the script that most people have prepared for it so far this Spring. In the last fortnight it’s still been making ground up on the -2 SD line, and on the 28th of May, was only the 6th lowest for that particular date in the 39 year-long series (fig 1). The sea ice is now just 5% below the long-term average for this date, and I’m sure some people are arguing that the extent has changed little since 1995, even though it maybe a lot thinner.
Meanwhile in the Antarctic, the sea ice is following the script and is the third lowest for the date of the 28th May, and 10% below the long-term average.
I’ve just been projecting forward the sea ice extent using the statistics the data that I download from the NSIDC. I’ve used the rate of change of the 10th percentile, and applied it from the 16th of April running forward (fig 1) to the extent on that day. If these projections are correct, I reckon that the Arctic summer minimum will be around 3.7 million square kilometres. This is the only the second time Arctic sea ice will have ever fallen under the 4 million level mark in the satellite series, that should happen at the start of September, which is what it almost managed to do last year. I’m sure a lot of people are looking at a much lower minimum, but the Arctic has put on a bit of extent this Winter, after suffering substantial losses during the run up to Christmas.
Rather more severe is the Antarctic projection for their upcoming Winter. I see the maximum at around 15.8 million square kilometres in the second week of September, the previous lowest maximum extent was 17.803 at the very start of the satellite series in 1978 (fig 2), so this figure is seriously low if it comes about. This year (the red line) will track much lower than 2017 (the black line), if anything the gap will widen between the two if anything, this is because up until the 28th of August last year the Antarctic was doing very well, with the extent slightly above average, but after that date the extent suddenly collapsed in September when it should really have been peaking. So I reckon that all eyes might be on the Antarctic this September, rather than the Arctic.
I will revisit these projections in September, it maybe by then, that I’ll have some serious egg to wash of my face, who knows my projections could end up being optimistic!
I will be the first to admit that what I’ve done is not scientific in any way, it’s just playing with the statistics of the last 40 years, but what the hell.