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Neven
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The ozone hole as a phenomenon is mostly associated with the Antarctic, but the Arctic also has one, much more variable in size than its Southern Hemisphere sibling. This winter the stratosphere over the Arctic has been extremely cold, causing a lot of ozone to be destroyed. If things keep... Continue reading
Posted 37 minutes ago at Arctic Sea Ice
As you can see in the animation below not that many changes in the Antarctic (considering the images are 6 days apart): But still plenty of melting potential with all that loose ice. Right now the Arctic is causing the drops in the Global SIE data, but if the Antarctic joins in with a couple of big drops...
Toggle Commented 14 hours ago on Global sea ice area record minimum at Arctic Sea Ice
Oh right, we're there already. Never mind! :-)
Toggle Commented 15 hours ago on Global sea ice area record minimum at Arctic Sea Ice
We're also discussing it in the comment section of the second Global SIA record minimum blog post, Rob. Someone brought up the fact that the NSIDC Global sea ice extent record minimum wasn't likely to be broken and that this somehow meant that a Cryosphere Today Global sea ice area record minimum didn't have any significance. But the NSIDC Global sea ice extent record minimum might well get broken too in the coming week, or perhaps even today.
Toggle Commented 15 hours ago on Global sea ice area record minimum at Arctic Sea Ice
Therefore the temptation of those who want Arctic warming to appear dramatic will tend to use area. Wow, this is such utter nonsense. If there is a long-term difference between satellite area and extent data, it's very small, because they're both produced consistently. This guy obviously started thinking about sea ice yesterday, and now thinks he knows it all. It seems he read David Appell's comment here as well. On-topic: JAXA reports another drop in SIE (the Arctic max is getting very, very interesting now), so let's see if the NSIDC reports a drop as well and what that means for Global SIE.
Toggle Commented 15 hours ago on Global sea ice area record minimum at Arctic Sea Ice
This isn't true with NSIDC data, though -- there the annual global SIE is, so far, only 3rd-lowest. And it doesn't look to be going much lower.... David, are you still watching? As expected Arctic SIE isn't increasing very fast right now. In fact, it went down 186K in the past two days. The Antarctic added another 27K, and so Global SIE currently stands at 16.827 million km2, which is just 61K above the 2006 record minimum (and 38K above runner-up 2011): This means that it will have its first shot at breaking the record tomorrow. Somehow I don't think it will, but it very well might in the next couple of days.
Yes, perhaps, but to be honest, I had expected more of that negative AO.
Now we move our eyes to the Arctic and keep an eye out for the upcoming maximum. Well, IJIS SIE has just dropped 141K in two days. When last year a drop of 161K occurred (around Feb 14th) it was the earliest and lowest max on record. The same thing happening again this year, would be crazy.
Indeed, the crosses are wrong, but the red trend line is correct.
Toggle Commented 3 days ago on PIOMAS February 2016 at Arctic Sea Ice
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Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: Big, big changes this month, and not for the good. Due to extremely high, or maybe I should... Continue reading
Posted 3 days ago at Arctic Sea Ice
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David, 1) The Arctic is contributing more than 12 million km2 to the 14.365 million km2 Global SIA record minimum. I can assure you there aren't many melt ponds in the Arctic right now. 2) Area data sets are as useful as extent data sets when comparing years, as long as everything is done consistently. Extent is better for short-term accuracy. In fact, operational analysis is even better than satellite measurements (see this blog post). 3) Again, Cryosphere Today Global SIA is used most widely, because it has been around for ages, has a Global SIA map on its homepage, and a data file with Arctic and Antarctic SIA already added up. That's why climate risk deniers use it, because it's easy. I'm not saying one is better than the other. I'm just as interested in NSIDC Global SIE. But it's CT Global SIA that broke the record.
This isn't true with NSIDC data, though -- there the annual global SIE is, so far, only 3rd-lowest. And it doesn't look to be going much lower.... CT SIA is better-known for its Global sea ice measure because the graph is readily available (as well as a Global SIA data file), but it's interesting to keep an eye on NSIDC Global SIE as well. I assume you base it on the addition of Arctic and Antarctic SIE data found here? What makes you think it doesn't look to be going much lower? There's plenty of melting potential in the Antarctic, I believe (I don't know all that much about Antarctic sea ice), and the Arctic could stall again next week. Given the fact that 2006 almost went below the minimum set at the end of January 12 days from now, I wouldn't yet call it for NSIDC Global SIE.
Thanks, Jim, I've added your long-term graph to the blog post.
New post is up to announce the record was broken. I trust Snow White will keep us informed if the GWPF/David Rose say anything about this?
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Okay, we can remove the question mark of the earlier blog post concerning Cryosphere Today Global SIA, as the record was broken yesterday: And here's how it looks on the graph from the Pogoda i Klimat website: It's not easy to see, but 2016 has dipped below the 2006 record... Continue reading
Posted 4 days ago at Arctic Sea Ice
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And there we have it, ladies and gentlemen, a new Global SIA minimum record at 14.365 million km2. :-)
Thanks, crandles. Just a 1K difference in 2006's favour. So, 2015 has now overtaken 2011, and there's a third chance of breaking the record tomorrow, the best so far.
NSIDC SIE and Daily Roos area and extent are all showing increases in the last two days, so Cryosphere seem to need an adjustment.. First of all, Cryosphere Today doesn't need any adjustment if it does things consistently every year. Each data set is different because of differences in satellite sensor, resolution, algorithm, land mask, area vs extent etc, etc. There is no need for perfect synchronicity as long as the same thing is done consistently for each data set. Second, Cryosphere Today data is usually reported 1-2 days later than other data sets. Either way, I've indicated several times that Arctic SIA is bound to go up a bit faster because of changing winds and temperatures in key areas like Bering/Okhotsk and Barentsz/Greenland Sea, so if a sufficient drop in Antarctic SIA to break the Global SIA record isn't reported today, there might not be a third chance. On the other hand, it looks like there is quite a bit of melt potential in Antarctica, so who knows. Not that this is important. Global SIA isn't a very useful measure. But records are always fun, and Global SIA is used by climate risk deniers as proof that AGW is a hoax. They'll probably be quiet until Antarctic SIA shoots up again, which it probably will after the El Niño is gone, because there seems to be something wrong with the southern system as well (and AGW may very well be the cause; think of changes in wind and ocean patterns, run-off from the continent, etc).
Yes, Global SIA gets its second chance at breaking the record, and like you say, because of a 22K drop in Arctic SIA (last time there was an increase of 51K), there's a reasonable chance of it happening this time. 44K to break the record, and just 24K to overtake 2011. Here are the changes from Feb 2nd to 5th: Ice getting smaller almost everywhere, with a piece detaching itself in the eastern Weddell Sea. We'll see what happens tomorrow. In the meantime, a nice Arctic Journal article some of you might appreciate on some Antarctic research done by scientists from the Alfred Wegener Institute: Several metre thick ice cocktail beneath coastal Antarctic sea ice Every winter in the Southern Hemisphere, the ocean around the Antarctic continent freezes. The “normal” sea ice formed on the surface of the Southern Ocean, however, is not the only ice that forms in the sea. During the same period, a remarkable habitat develops hidden beneath the solid sea ice cover: a several metre thick layer of loose ice crystals. Some areas underneath sea ice in coastal Antarctica then resemble a cocktail glass filled with crushed ice – the difference being that the crystals in this layer grow to disc-shaped, millimetre-thin platelets. (...) The researchers are convinced that platelet ice plays an important role in the ice regime of the Antarctic. After all, the seasonal sea ice in Atka Bay freezes to an average thickness of two metres in the winter. The platelet layer underneath, however, reaches an average thickness of five metres over the course of a year. In some places it was up to ten metres thick. This means that a significant amount of the ice exists in the form of platelets. "To understand the situation of the Antarctic sea ice and to assess a possible influence of climate change, it is likely that more account must be taken of platelet ice," says Mario Hoppmann. It is not currently possible to properly assess the significance of the platelet ice across the Antarctic. The new findings give cause for hope that its distribution and therefore also its role will soon be understood to the same extent as its formation. Platelets, which later accumulate in the platelet layer, form beneath the ice shelves of the Antarctic, those parts of the mighty ice sheet that float on the sea. The platelet ice cycle begins as salt-rich water in the coastal ocean sinks and slides underneath the ice shelves, which it then slowly melts. The result: The melted fresh water mixes with the salty ocean water underneath the ice shelves. On the surface of the sea, this water mix would freeze immediately, because its temperature is well below the surface freezing point. Because of the high water pressure in the depth of the sea, the mix initially stays liquid – physicists call this a "potentially supercooled" state. Because this water mass has a lower density than the surrounding seawater, it slowly rises at the base of the ice shelves. The water pressure decreases and as soon as a critical shallower water depth is reached, tiny little ice crystals start to form. These then grow to form those delicate ice platelets that later accumulate as platelet ice underneath the sea ice at the surface. Photos and video in the AWI press release.
Antarctic SIA didn't drop, but increased by 14K, so Global SIA now stands at 14.517 million km2, which is 126K above the 2006 record minimum, a bit too much for one leap. But maybe it can creep closer again tomorrow, as a very small uptick of 5K was reported for Arctic SIA.
That's right, crandles. Remember, a drop of at least 89K needed to be reported for Antarctic SIA to match the 2006 record minimum. A drop of 27K was reported, however, and so the difference with the 2006 record minimum is now 62K (42K needed to overtake 2011). First chance missed. In the meantime an increase of 51K was reported for Arctic SIA, so Antarctic SIA needs to drop 113K (there's a 1 day difference between numbers reported for Arctic and Antarctic SIA) to break the Global SIA record. I'd say that's rather unlikely, but maybe it can get closer still, and position itself ideally for the kill. ;-)
VaughnA, I have received an answer to your question via mail from Christian Knoblauch of the University of Hamburg: A quick response. There are two papers that have modelled microbial heat production in permafrost (Khvororstianov see attached) and one published last year (Hollesen, J., H. Matthiesen, A. B. Moller, and B. Elberling (2015), Permafrost thawing in organic Arctic soils accelerated by ground heat production, Nature Climate Change, 5(6), 574-578.) that measured them. To my view the Kvorostianov papers overestimate heat production since they use the heat production generated from chemically oxidizing glucose which is not the most common substrate in permafrost soils. I hope this helps
I mean I'm vain enough for that, Jim. ;-)
Toggle Commented Feb 4, 2016 on A difference in nonsense at Arctic Sea Ice
I'm not too vain for that, Jim. :-)
Toggle Commented Feb 4, 2016 on A difference in nonsense at Arctic Sea Ice
Here's an animation of Jan 31 - Feb 02: It seems most of the action is now going on in the Bellingshausen and Amundsen Seas. That's the ice just above that big blob of sea ice in the Weddell Sea (here's a map). Not just on the outside, but I think I'm also seeing polynyas along the coast getting bigger, and a change in SIC colour. Could be more decrease coming from there.