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Neven
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Over on the Arctic Sea Ice Forum I have posted an animation of the current sea ice retreat in the Kara Sea (south of Novaya Zemlya), as compared to the retreats in 2011 and 2012. The big question is whether the ice will get shoved back again, or the water re-freezes again (like happened in 2011 and 2012), or whether it will stay open this time. If it does, that will be unprecedented.
That's a great chart that shows the main cause of the lowest maximum on record, Jim. Thanks a lot.
Interesting that Bering and Okhotsk were the biggest contributors to the new record - I wouldn't have guessed that after the series of Atlantic-side lows and heat advection this winter. Indeed, iceman. I concluded it when looking at the regional graphs, particularly Wipneus' Uni Hamburg AMSR2 sea ice area overview graph. Of course, those lows also caused a kind of Beaufort Gyre-type export on the Atlantic side of the Arctic. I expect a flattish graph for the next week or two, with erratic gains in Bering, Baffin and maybe Greenland followed by a partial refreeze in Kara. I don't know about Bering and Baffin, but you may be right about Kara. The open water 'refroze' again in 2011 and 2012. It depends on the winds also.
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After a drop of almost 262 thousand km2 in just three days, it looks highly likely that the maximum for sea ice extent was reached two weeks ago, according to the data provided by JAXA, the Japan Aerospace Exploration Agency (via ADS-NiPR ; it used to be provided by IJIS).... Continue reading
Posted 3 days ago at Arctic Sea Ice
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Indeed, Wayne. No year since 2005 in the IJIS/JAXA data set has had a larger daily drop after a century break. A further region by region is needed, but CT is still down. I don't think Cryosphere Today will ever go up again, as the scientists involved have moved on. I wish they'd announce it officially though, so we could thank and honour them for their pioneering work in making sea ice data available to the public. As for regional graphs, there's a dedicated page on the Arctic Sea Ice Graphs website, with a collection of both MASIE and Wipneus/Uni Hamburg AMSR2 regional graphs. It's clear that extent is low mostly because of what is happening on the Pacific side of the Arctic, with Bering and Okhotsk going low. But SMOS is indicating that there is a lot of thin ice on the Atlantic side of the Arctic, and ice is already retreating in the Kara Sea (from the southwest shores of Novaya Zemlya). Given the weather forecast for the coming week, this is going to continue, and so I expect 2017 to stay low, if not lowest, on the JAXA SIE graph.
Toggle Commented 5 days ago on PIOMAS March 2017 at Arctic Sea Ice
A 112K drop even, if you are referring to JAXA, Wayne. And yes, I would call the max too, another record low on record. Very impressive. I expected it would go a bit higher, but it didn't.
Toggle Commented 6 days ago on PIOMAS March 2017 at Arctic Sea Ice
Whether the max has been reached or not, it looks highly likely that it will be a new record lowest max (JAXA SIE), third in a row to stay below 14 million km2.
Toggle Commented Mar 12, 2017 on PIOMAS March 2017 at Arctic Sea Ice
And Slater's data seems to be area-weighted, but as you correctly point out it is 925 hPa, which is too far from the surface to be indicative of ice growth during winter. I understand, but the surface and 925 hPa aren't entirely independent from each other, are they? Isn't there some correlation, or do inversions etc totally screw that up? The nice thing about the 925 hPa temps Slater used, is that it is Arctic Ocean-wide. Wouldn't that be better than just 80N?
Toggle Commented Mar 11, 2017 on PIOMAS February 2017 at Arctic Sea Ice
Andrew Slater also had an FDD graph for the whole Arctic Ocean (see here and click 'about this data'). Wouldn't that be more useful?
Toggle Commented Mar 10, 2017 on PIOMAS February 2017 at Arctic Sea Ice
The reasoning makes sense, but the question is whether those 'hot' spots are real (perhaps by comparing to previous years). Also, if you look at this sea ice drift map for December, you'll see that the ice didn't pull away from those hot spots, but rather from the Kara and Barentsz Seas.
Toggle Commented Mar 9, 2017 on PIOMAS March 2017 at Arctic Sea Ice
I may be missing something. always assumed that snow has higher albedo than ice (at least in the optical range), and that a nice thick layer of snow (think of +50 cm) delays onset of surface melting. However this thickness seems more the exception in the Arctic except for the core of the oldest ice. You may be right, navegante. In fact, according to this Wikipedia article on Albedo fresh snow has an albedo of 0.8 to 0.9, whereas ocean ice has an albedo of 0.5 to 0.7. So, I clearly have that wrong. What I meant to say, was that snow may cause an earlier melt onset because it will melt easier/faster than ice when confronted with down-welling longwave radiation (due to clouds). This will cause the albedo to go down, so that even if it re-freezes, it will be more vulnerable to melting when shortwave radiation (ie sunshine) takes over. But to tell the truth, I don't know nearly enough about these things to make definite statements. It's how I imagine things could go and why it would be a bad thing if there actually is more snow on the ice than usual..
Toggle Commented Mar 9, 2017 on PIOMAS March 2017 at Arctic Sea Ice
Thanks, Rob. I do not demand perfection from either models or satellite observations, but I wish this divergence could tell us something about the amount and distribution of snow on the ice, and then compare that to other years. A bit like we divide area by extent to get an idea of the ice pack's compactness. Or volume by extent to get an average thickness (like I do with PIJAMAS). Unfortunately, both modelled and observational data are highly uncertain (maybe the agreement up till now and the current divergence or coincidental). And then there's the differences between the PIOMAS and CryoSat-2 (AWI) grid, average vs effective sea ice thickness (as explained here), and so on. There's no way to quantify this. But maybe by comparing to ASCAT and other sources, and by making monthly SLP and SAT maps, we can get something of an idea.
Toggle Commented Mar 9, 2017 on PIOMAS March 2017 at Arctic Sea Ice
PIOMAS and DMI are not in agreement at all. DMI shows current volume in line with last year. Also OSISAF shows an 100%+ increase in volume over 2006. What's your take Neven? I'm not an expert, G man, but my experiences with the DMI volume maps are such that I don't place a lot of trust in them. I look at them occasionally, nevertheless, because every piece of information can be useful. However, there's a much more interesting divergence as we speak, and it's one between PIOMAS and CryoSat-2. That's the interesting bit I wanted to add to the blog post, which I have just published (below the monthly thickness graphs). The implications could be significant, but there's no way of telling, although I will try and have a look before the melting season starts.
Toggle Commented Mar 8, 2017 on PIOMAS March 2017 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: There haven't been any major changes compared to last month, and that's good, because it means things haven't... Continue reading
Posted Mar 7, 2017 at Arctic Sea Ice
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Zebra, either the snark disappears, or you disappear. Show some respect and possibly some work. Rob has done his bit many times over.
Toggle Commented Mar 3, 2017 on PIOMAS February 2017 at Arctic Sea Ice
So would it be fair to say that neither annual average nor summer minimum are, in themselves inherently more useful if they aren't viewed within the extenuating context? Both can convey meaningful information relative to long-term trends? Yes, I would say that's fair. Of course, the summer minimum is most easily grasped by people, and can be illustrated with a satellite image. As for extent vs area: Area is 'better' most of the time, except when there are a lot of melt ponds. Especially now that the ice pack consists of smaller, thinner floes, that easily get pushed around by winds, causing the ice pack to disperse more than it used to. These holes in the ice pack are counted for area, but not for extent. But again, every source information is useful, as there are a lot of things we don't know. To some people that's a comfort, but to not have enough information when things are obviously changing so fast and on such a large scale, is the exact opposite of comfort, IMO.
Toggle Commented Feb 16, 2017 on PIOMAS February 2017 at Arctic Sea Ice
As I've said several times, annual averages are a useful part of the puzzle, but they're not the entire puzzle. Just last year we've seen how certain information sometimes won't be conveyed by an annual average of extent. Extent was in record low territory for most of the year, and thus the annual average was low as well. One would assume that this meant that the minimum record was smashed to pieces, except it wasn't, because June, July an August were mostly cloudy, and so the extent decrease slowed down considerably and the 2016 melting season came in 2nd/3rd (depending on which data set you use). Now, that's the kind of information the annual average won't convey, and so you need to look at other sources of information as well. Or like I said in this blog post about the MASIE annual average that was abused by a climate risk denier to give the impression that nothing is going on in the Arctic: It's like measuring your weight every day from Jan 1st to Dec 31st. You're really overweight at the start of the year, then you stop eating for half a year and you get really thin and undernourished, followed by a junkfood binge after which you're overweight again. But then you take the average of all those daily weighings, and presto, your average weight is perfect! But, one might ask, how's your health? As far as that 'Javier' is concerned: I've discussed with him over at Paul Homewood's blog. You can get quite a long way with him, further than most climate risk deniers, but you lose him when the time comes to draw conclusions (that's when the dissonance takes over). There's not much to learn over on Climate etc., especially about Arctic sea ice. All Judith Curry cares about, is disinforming people and somehow get paid/attention for it.
Toggle Commented Feb 15, 2017 on PIOMAS February 2017 at Arctic Sea Ice
Antarctic sea ice hits lowest minimum extent on record. Not so convenient if your argument has been that Arctic sea ice loss is fully compensated by Antarctic sea ice gains (which isn't true anyhow), or that Antarctic sea ice gains proved Global Warming was a hoax. ;-) I'd be surprised if this is the start of a new trend, as Antarctic sea ice is a pretty volatile measure, and this seems to have to do with ENSO. But if it is a new trend, that won't be good.
Toggle Commented Feb 13, 2017 on PIOMAS February 2017 at Arctic Sea Ice
Someone over on the Arctic Sea Ice Forum has published some excellent PIOMAS vs CryoSat-2 maps. Here's one showing the difference between the two for January 2017:
Toggle Commented Feb 10, 2017 on PIOMAS February 2017 at Arctic Sea Ice
Indeed, Wayne. Indeed.
Toggle Commented Feb 7, 2017 on PIOMAS February 2017 at Arctic Sea Ice
From Climate Central: The Winter of Blazing Discontent Continues in the Arctic A massive storm is swirling toward Europe. It’s a weather maker in itself, churning up waves as high as 46 feet and pressure dropping as low as is typical for a Category 4 hurricane as of Monday. The storm is to the southeast of Greenland and its massive comma shape has made for stunning satellite imagery. The storm is expected to weaken as it approaches Europe, but it will conspire with a high pressure system over the continent to send a stream of warm air into the Arctic through the Greenland Sea. Temperatures are forecast to reach the melting point in Svalbard, Norway, an island between the Greenland and Karas Seas. The North Pole could also approach the melting point on Thursday. It’s just the latest signal that the Arctic is in the middle of a profound change. Sea ice extent has dropped precipitously as has the amount of old ice, which is less prone to breakup. Beyond sea ice, Greenland’s ice sheet is also melting away and pushing sea levels higher, large fires are much more common and intense in boreal forests and other ecosystem changes are causing the earth to hyperventilate. Together, these all indicate that the Arctic is in crisis. It’s the most dramatic example of how carbon pollution is reshaping the planet and scientists are racing to understand what comes next.
Toggle Commented Feb 7, 2017 on PIOMAS February 2017 at Arctic Sea Ice
Note that in the sentence in the article it states "all the Septembers", which should of course include 1981. The reason that I mentioned it is in case Neven wants to make a change to that sentence. I've squeezed in a 'nearly' in there. And corrected the typo (should be 80s). :-)
Toggle Commented Feb 6, 2017 on PIOMAS February 2017 at Arctic Sea Ice
It was a convoluted way of saying that only 2007 and 2016 saw a smaller increase than this year in January (all of them below 3000 km3), and so the gap between 2007+2016 and 2017 didn't get wider.
Toggle Commented Feb 5, 2017 on PIOMAS February 2017 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: Things just keep getting worse. After this year's trend line went well below all others last month, I... Continue reading
Posted Feb 5, 2017 at Arctic Sea Ice
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Where is everyone over the past three days, no posts. Is there a problem with the site? It is indeed mostly because of the Arctic Sea Ice Forum where it's easier to post images, and there are more thrads specific to different subjects. But things have always been quiet around here during the freezing season, although I think they would be a lot less quiet if it weren't for the ASIF, given that this freezing season is even more abnormal than last year's. Total annual volume loss in recent years according to PIOMAS (max-min between brackets): 2006: 16198 (25191-8993) 2007: 17345 (23803-6458) 2008: 18087 (25159-7072) 2009: 18235 (25074-6839) 2010: 19693 (24275-4582) 2011: 18375 (22677-4302) 2012: 19692 (23365-3673) 2013: 17940 (23332-5392) 2014: 16306 (23118-6812) 2015: 18698 (24394-5696) 2016: 18316 (22717-4401) PIOMAS is going to update in a few days. It will very likely still be lowest on record.
Toggle Commented Feb 1, 2017 on A new Arctic feedback (?) at Arctic Sea Ice