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Enno
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Thanks A4R for that briefing by the UK Met Service.
Toggle Commented Feb 10, 2014 on Looking for winter weirdness 2014 at Arctic Sea Ice
Re: battering ... from incessant storms : the NOAA´s OPC has a statement up on that: http://www.opc.ncep.noaa.gov/Loops/Atlantic_December_2013/Charts2.php "December 2013 featured an extremely active, and very intense low pressure track across the North Atlantic ocean basin." And its continuing, though with somewhat reduced intensity; the next hurricane force low is predicted at the weekend or so and going to hit Ireland. I have not yet seen an explanation for why the N. Atlantic is this extremely stormy this winter. It does seem to serve to pump warm air arctic-wards.
Toggle Commented Jan 29, 2014 on Sea ice atlas at Arctic Sea Ice
re: ice movement vectors. the longer this ice movement goes this way, the more it might act to decrease the chance of a collapse of the ice in the east sib. sector like in the last season. This must act to increase ice thickness in the Laptev, which is usually the source region for the transpolar drift. There has been no sight of the flaw polynya in the Laptev recently, whereas there has been a flaw polynya at Barrow apparently. So this ice movement (driven by the winds) might be rather a good thing in the interest of the ice. OTOH for the Kara Barents region it is clearly not good. my hope is on what the weather forecasters say.They are talking about the splitting polar vortex, bringing a part-vortex to Siberia. That could mean an east to west stream later (end january into Feb) across the arctic into Kara-Barents, allowin ice cover to recover there and giving it time to grow. (I dont like the cold they promise us to get from that, but rather a bit of freeze here than no ice growth up there).
As such, it is of course completely justified. Couldn´t agree more.
Toggle Commented Jan 2, 2013 on Shell drill spill? at Arctic Sea Ice
That is a spoof site. http://arcticready.com/social/gallery although quite thoroughly made. "Shell.com" linking back to the same site also is a giveaway.
Toggle Commented Jan 2, 2013 on Shell drill spill? at Arctic Sea Ice
Hi all two things of potential interest for all, through not narrowly related to the ice per se: another article (media, not science) suggesting a cold European winter based on an anticorrelation with hot Greenland SST, but not a serious prediction: http://sciencenordic.com/warm-seas-around-greenland-may-indicate-cold-european-winter And, a very fresh youtube movie on a related theme, the possible fate of the thermohaline circulation (AMOC) - summary of a just concluded EU project, THOR: http://www.youtube.com/watch?v=ovIvtKSQy9Y groeten to all
Aaron, thanks. I agree completely, but my keyboard ate a more explicit reply (sorry). (In short .. I woke up to a sense of unreality about the weather in the same year 2006-7 that led to the first great ice collapse: as we had a 3/4 yr of semi incessant SW winds, from the atlantic, that annoyed me on my daily bike commute ... I realized only later that those winds were part of the same abnormal weather that transferred so much heat into the arctic that year; which led me to turn into an arctic watcher ... as things go.) Same sense of unreality I had when I looked at the (excellent) thickness maps A4R put up above. There´s something seriously weird there "above" Franz Josef Land, as werther et al also said. it looks like there is a strong west drift pushing the ice nearly reverse of the usual transpolar drift direction, see Neven´s graphs page. But what is cause and effect there? That ice edge seems to behave like a half-polynya? Has that ever happened before? Where is this west-to-east stream (along the north edge of the siberian high) coming from? Neven: I write actually to point out a development on a related blog, http://fromtheblueside.blogspot.de/2012/11/new-projects.html if that blog follows through that could turn into a helpful site, like "ask-an-oceanographer". That could be very useful, and people here could find it interesting to get answers there.
Toggle Commented Nov 13, 2012 on Bilateral freezing at Arctic Sea Ice
... "I think bilateral freezing on this scale is a first. " ... Is it? Looking at CT ice plots: (Laptev/ESAS) terms: seaside: ice cover grows from the basin until it hits land landside: ice growths all from land until it hits ... ? bilateral: as in the animation: two growth fronts meet surrounding a middle opening zipper: shelf sea never fully open in summer, closes like a zipper along coastline 2000 Oct 10 largely seaside 2001 Oct 1 largely seaside never fully open 2002 Oct 15 largely seaside (zipper freeze) 2003 Oct 17 bilateral 2004 uh no images ? 2005 Oct 21 half zipper, half bilateral 2006 Oct 15 bilateral 2007 Oct 20 half zipper, half bilateral 2008 Oct 16 mostly bilateral 2009 Oct 11 mostly seaside (leans bilateral) 2010 Oct 19 bilateral 2011 Oct 18 ... a bit bilateral then zipper 2012 Oct 22 strongly bilateral to me this looks like a trend: * progressively later freeze (later date of similar state) (not entirely unexpected this trend, ahem) * progressive change of way of freeze from seaside/zipper to bilateral. it also makes sense: if the northern sea route didnt open up in the first place then one cant really have "bilateral" freezing ... This year does stand out in lateness and clarity of the "new" pattern; even though this is the marginal sea that froze first. if one looks closely at the animation, then one can see that the ice that grew "out from land" doesnt just do that, it seems to grow near cost parallel towards the east. Best spot to watch: Lyakhovsky island (of the New Siberian Islds), before 20th Oct. Why this directionality? is this some consequence of sea currents? self answer using NCEP : prevalent west winds there at the time. Still: ice growth in wind shadow areas? Does that make sense?
Toggle Commented Nov 12, 2012 on Bilateral freezing at Arctic Sea Ice
why would a record low melt (record low surviving ice) have to be followed by less winter ice? take the thought example of a just full meltout of ice in summer. Then all ice in fall and winter has to grow from scratch. (In reality more complex as it will depend on state of the water/mixing etc but bear with me). In that argument, the amount of ice formed depends on the strength and weather etc. of the winter - and not on the weather of the preceding summer. There should be no reason to expect that a specially low ice winter has to follow a low ice summer. Unless it can be shown that low-ice summer conditions by themselves prime the atmosphere for less ice growth in winter. As far as I am aware (big caveat), that is not clear. In opposition, a low ice winter DOES prime a subsequent summer for low melt, if there is simply e. g. less ice thickness. So I would suggest that the natural expectation should be that summer ice extent has a memory of the preceding winter, but winter ice extent not a memory of the preceding summer. Is anything wrong in this argument? case in point - last winter´s end-winter growth spurt, happening (as Chris points out) in completely seasonal seas. How could such a thing possibly be foretold from the end-of.summer ice state? Ergo, how could one even expect that winter low should follow summer low a priori? I do suspect that a summer low can create special conditions in either sea or atmosphere to hamper winter´s ice growth abilities; but then people might better try and figure out what exactly these changeways are in order to learn to predict whether winter will be high or low ice. (case in point - Beaufort upwelling retarding ice growth for several weeks circa; big aha event for me).
Toggle Commented Nov 12, 2012 on Bilateral freezing at Arctic Sea Ice
Enno is now following Neven
Nov 3, 2012
thank you A4R for the link to Godiva. I tried using it for the current state of the Beaufort Sea. At first it was black, however adjusting the contrast settings (rescaling) did bring out data detail for the Beaufort Sea. I dont know what the original source of the data is, but the site gives considerable spatial detail. Specifically, it shows several warm eddies, where warm means 273.5 K (definitely above 0 C). However the salinity in the Beaufort Sea was to my surprise very low - the lowest in the inner Arctic about - down to 26 permil. Comparing the T and S maps, shows that the warm eddies are salty and the low-salinity water pool in the Beaufort is somewhat colder, maybe it is freshwater from the Mackenzie - definitely looks a little bit like that from the swirls. the warm somewhat more saline eddies at the coast (>28 permil) dont look like they might be derived from the Bering Sea area: the water there is much more saline (pacific) and if it were mixed down by cooler freshwater it could not be that warm. So I think this view via Godiva strongly supports upwelling (roughly along the lines of the Yang presentation I mentioned earlier - also agreeing with his observation of counterintuitive salinity seasonality in the Beaufort). One would then have to expect that the refreeze in the Beaufort will stall for quite a while yet. I dont know how normal or unnormal this is. unfortunately I dont know how one posts images .. but it shoud not be difficult to get side by side T and S maps from A4R´s Godiva link, using appropriate scaling. thanks again!
Toggle Commented Nov 3, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
Continued search on the curious Beaufort Sea behaviour has turend up this: http://www.arcus.org/files/projects/education/634/seasonality-yang_presentation.pdf a presentation from (2010?) by someone from WHOI called Jiayan Yang. It looks rather pertinent. In short it says: Yes, especially the Beaufort Sea shelf is a location of seasonal upwelling, due do what he calls the Ekman layer (roughly, I understand it as wind pull on the sea causing upwelling where the pull is divergent) and he shows this upwelling especially strong in the Beaufort Sea during autumn. (Slide 8) Slide 10 refers to "offshore ekman transport" and I understand slides 11, 16, 22 etc to imply that the upwelling on the coast bringing warmer and saline water upwards is combined with downwelling at the ice edge. slide 15 will be interesting to the people following the atmosphere interaction. Having seen this I suspect that this is the actual answer to why the Beaufort Sea lags so behind in refreezing. (e. g. slide 19 Ekman heat flux, practically equals the area that is now still ice free). current OSTIA SST data say that the water in the Beaufort sea is still at 0 deg C, full 1.5 C hotter than normal, and one would then have to expect that yes theres quite massive upwelling going on (Ifremer buoy data from further north (73.995 / -137.746) show 0 C water only in 70-90 m depth). Thats the only source for such warm water I could yet find in the area. But its saline water. I couldnt yet find salinity data for the Beaufort hot area.
Toggle Commented Nov 2, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
hi kris this is interesting thanks for the parade. it is a very suggestive comparison (regarding a real change of state) for the Kara Sea but less so for other areas. it made me think that it should be possible to judge the progress of the change towards seasonality in any one of the geographical basins from changes in the shape of the anomaly plots. (referring to the CT area plots). i. e. where there´s a basin that used to be completely perennial, and now begins to become seasonal, one would expect to see a single annual dip curve on the CT anomaly plot - such as for example the central arctic basin (region 1). Whereas in basins where there is already a developed summer minimum, one would expect to see a double-dip anomaly curve with the two anomaly peaks spreading backwards through spring and forwards through autumn constricting winter. That is really well visible in the Kara sea plot (region 7). And where the whole ice is climatically restricted anyways to the winter season, there one would expect these split anomaly peaks to merge into a single peak in wintertime. Example: Sea of Okhotsk, region 14. So maybe one could devise a measure of tracking the change from perennial to seasonal to ice free, for specific regions, from a shape analysis of the anomaly plots. That might be a useful visualisation tool. Especially as one could then maybe link this measure to atmospheric or oceanographic signatures of the respective years to try and isolate direct mechanisms. hm, but thats just me thinking. surfing through the data, the Sea of Okhotsk btw is even more anomalously warm than the Beaufort Sea (+2 to +3 deg C anomaly). What is going on there? That should be interesting to watch how it affects the refreeze.
Toggle Commented Nov 2, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
these people might know: http://www.whoi.edu/page.do?pid=66296 but I cant find yet any results of their this year´s cruise.
Toggle Commented Nov 1, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
Hah. idunno. had said nothing becuase I was still trying to digest that masters thesis. Hah, you talk about a correlation! I still have it open there, but admittedly I dont know what to do with it. this troubles me often with such correlations; when theres a readily visible physical explanation underlying it: fine. But how "knows" water or ice in the Beaufort how hot it had been 5 months before in the Caribbean? that beats me. if there is such a teleconnection (and no doubting that work) then there must be a mechanism. What would that be? (The famous baby-stork correlation is after all also due to a logical, if convoluted, mechanism).
Toggle Commented Nov 1, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
thanks all for the answers. So some of you think that the Beaufort Sea lack of ice is a consequence of more summer sunshine (solar energy) due to it being open in the maximum radiation period. (Werther) Others think it is upwelling warm water (p-maker: Local summer sunshine is not enough) though of a bit unclear origin. I like this : dont get me wrong - differences in perception is the first step to better knowledge. (and at least it wasnt apparently something trivially simple to ask.) wonder what would be an observation to make that could help deciding which option is the correct one.
Toggle Commented Nov 1, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
huh, yes, I remember that people discussed the warmth anomaly of the Beaufort Sea months back. Or, discussed that it was weird; but I dont recall it was well understood back then what exactly was happening. Its obvious that the Beaufort Sea has taken a lot of extra solar energy this year but so should have the East Siberian and Laptev Seas, which had similar low ice and are at similar latitudes. but maybe you are right Neven and this ice-delay in the Beaufort Sea is just an expression of higher abnormal heat content? at least SST images in your earlier posts are consistent: http://neven1.typepad.com/.a/6a0133f03a1e37970b0176176f64c7970c-350wi I guess my question then becomes rather, why is the Beaufort Sea having this anomalous behaviour (of which ice delay is an expression)? for the Barents-Kara area people said that warm atlantic waters are building eastwards, at least I believe I can understand that. But for the Beaufort Sea I dont get where that effect comes from. It isnt pacific warm water - that is at 75m depth and not at the surface. It also isnt atlantic warm water - that is even below that (at that part of the arctic). It isnt just solar heat - as that should just as much have affected the siberian shelf seas. Or am I wrong therein? What am I missing? (Quite possible that the answer was given here already while back when I wasnt reading).
Toggle Commented Nov 1, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
on the theme of winter weirdness. I have a question. I am watching the ice grow, and the east siberian shelf is now pretty much iced over, and in the Kara the ice is growing out from the land as well. That all seems normal. (?) But what is with the Beaufort? The Beaufort is shown as still much ice free on the Bremen AMSR2 maps. indeed on the regional graphs, the Beaufort anomaly is even still growing, and has reached record magnitude because there is no ice. what is up there? isnt it as cold there as at the other segments of the arctic margin? and, apart from why that is; what are the consequences of such an extended delay in ice in the Beaufort? thanks E.
Toggle Commented Nov 1, 2012 on Looking for winter weirdness 2 at Arctic Sea Ice
(this is new to me: threads now on this site?) any case in reply to Chris Reynolds: I remember one other discrete thing that could be seen as a predictor of the 2012 ice loss magnitude. It was in the paper: Krumpen et al, Laptev Sea Ice outflow, http://www.the-cryosphere-discuss.net/6/2891/2012/tcd-6-2891-2012.pdf which came out before the full extent of the 2012 season was visible. In it they looked at sea ice formation in winter in the Laptev which is (they say) one of the main formers of seasonal sea ice in the arctic. They explain that the Laptev polynyas generate a large part of arctic seaconal ice because the wind blows the continually freshformed ice from these polynays into the larger arctic basin, to accumulate or drift towards the Fram strait. Now they said that the export from the Laptev would be a key predictor of the following season´s ixe extent, because strong export meant low ice thickness - basically blown out by the wind before it could grow thick in its "babyground" Laptev. So they noted that the ice export (to the N, into the CAB) of the winter 2011-12 was off the charts strong (implying exceptionally low thickness)(p. 2907). The paper came out before the season was full - but methinks their proposed correlation has been holding quite vividly. So this might be a thing to watch in the winter: how is the seaonal ice in the marginal seas developing? Does it stay in place and grow thick? Then the following season would be not record. Or does it remain mobile, gets blown around and continually refreshed? Then one might expect a strong melt year the next year. Looking from POV of the atmosphere, one would then have to watch the wind field in the eurasian marginal seas.
Werther, that is one impressive graph. Thank you. (Are there meteorologically versed people here who can spell out what such a heat anomaly will do to the atmosphere in the short run?) /Ggelsrinc, we may have talked at cross purposes. If you want to artificially save the last 1 MKM2 ice, that´ll be where you indicate; but then the Arctic Ocean would be functionally seasonal already: for the climate effects the damage would still be done./
Toggle Commented Oct 10, 2012 on Naive Predictions of 2013 Sea Ice at Arctic Sea Ice
" ... thickening the sea ice where needed, we could expand next year based on what survives..." I suspect there´s a misconception there. If we get to a basinwide seasonal ice - which we will soon; the only thing in doubt is how many or few years it will still take - then there won´t be any winter ice surviving. That´s the definition of the new state: unaided, the winter won´t be able to grow ice thickness anymore that´s able to not melt complelety. So any "exit route blocking" artificial ice would be uselessly blocking the exits of an otherwise ice free arctic summer basin. So, conceptually, if we wnated to make an artificial ice cover we would have to make it over all the areas where we want it. And; it can be even worse: if freshwater stratification indeed breaks down (which I dont know if it will, but it might) then the entire idea becomes nonsensical anyway: we could just as well try artificial ice growth in the North Atlantic then. the only (un?)realistic strategy I can think off to recreate the ice would be to stop emissions and actively draw down the already too high CO2 in the atmosphere, so that the winter can again grow ice thick enough to become perennial.
Toggle Commented Oct 10, 2012 on Naive Predictions of 2013 Sea Ice at Arctic Sea Ice
The AWI page for the expedition is here: http://www.awi.de/en/news/newsflash/2012/august/ where they refer to two more running blogs (one in German one in English). Apparently they are even now deep in the growing ice. From the style of the images it reminds me of this blog entry, http://www.geo.de/blog/geo/polarstern-expedition/wissenschaft/im-kalten-fliegt-s-sich-besser-von-stefan-hendricks-arbeitsgruppe-meereisphysik-awi?LTblog=26d6c765186d98d337c7ebff6abcc637 which would mean it was end of September. Once there, one should note the last blog entry, http://www.geo.de/blog/geo/polarstern-expedition/leben-an-bord/polarstern-hovercraft-sabvabaa-huckepack?LTblog=26d6c765186d98d337c7ebff6abcc637 highly impressive photos of current conditions up there. From the interview with the hovercraft ice researcher, I translate: "Q: Yngve [Kristoffersen], you were very long out here during the new ice minimum. How did this extreme ice recess appear to you? A: (I noticed) especially the very warm air temperatures. I really hadnt counted on this: it was so warm that my fresh food turned bad (victuals). Usually, I just put them outr there in chests, nature cares for the cooling. But we had severe plus-centigrades, and the vegetables just didnt keep themselves. Also, the ice has gotten very soft, one coud see it strongly melting everywhere. And it rained, even in the middle of September I experienced incredible rains, (it was) as if I would be back in the mountains." their english blog is actually very good reading too!
Toggle Commented Oct 5, 2012 on More vids at Arctic Sea Ice
Jim, that´s good. However, the anomalies in water temperature in the current going around Greenland do not tell you that their anomalous warmth comes from the Gulf Stream. As far as I could see on the maps, already the southward flowing Greenland Stream between Greenland and Iceland has anomalies comparable to those in the Baffin Bay. I would therefore naively think that it can be that it brings its (relative to climatology) higher heat content with it, than that it gets it from the Gulf Stream. (This is entirely possible - that flow carries a significant heat return derived from the Atlantic warm input, nonwithstanding that it is a cold flow at its location). To make the specific Gulf Stream connection one would have to have more specific evidence that that is the case. Maybe there is such evidence but do you (or someone) have any? Up thread, it has been speculation; legitimate for sure but not to be confused with actuality. The anomaly map at http://polar.ncep.noaa.gov/sst/ophi/color_anomaly_NPS_ophi0.png does not seem to me to agree very well, moreover with that at http://ocean.dmi.dk/arctic/satellite/index.uk.php Basically, I can´t follow through the apparent data what exactly it is that brings you (or others) to suggest "the Gulf Stream", or a derivative of it would at this moment be delivering abnormal heat to Greenland waters. Well one could speculate that the cold countercurrent is abnormally warm because higher than usual heat has been input under the Arctic through the Barents and Kara (as is known it has); but to call that heat from changes in the Gulf Stream would be quite a stretch.
Toggle Commented Oct 5, 2012 on PIOMAS October 2012 (minimum) at Arctic Sea Ice
I would like to draw people´s attention to some ocean buoy data, namely ITP-41. It is drifting in the Beaufort Gyre. ## http://www.whoi.edu/page.do?pid=49795 If I can believe what the data page says (I have no experience with this), then the buoy was deployed in 2010, and is still transmitting regular T&S depth profile data as of today. If I can take that at face value then the buoy has seen the whole melting season 2011, and now the whole melting season 2012. So one can compare. One should look at the "plot of ITP T&S contours". That gives a page showing Temperature and salinity data, as depth profiles versus time. There are a lot of disturbances some of which for sure are technical (unreliable data), which I am in no way qualified to even recognize. However, the general structure of the surface layer through a melting season is clearly visible. Especially, I want to draw attention to the top plot, of temperature, in the top 200m. One can actually see the heat pulse of a melting season. That of melt season 2011 starts at ca. day 570 and one can se the thermal pulse, as it moves deeper, and how it is followed by a cold pulse from the developing top winter, while it still moves deeper. And then from about day 900 on comes melt season 2012. (one can actually see the august storm as a short mixing event around day 950 being August 8 2012). what strikes me about this figure is a comparison of the strength of thr 2011 thermal pulse versus that of 2012. This is solar energy input into the water (nothing to do with warm ocean heat flux from below). Now, as shown in the location data the buoy has drifted, and it does have moved south so the two seasons are not completely comparable, but the latitude difference may be no more than 3 degrees if I can believe the data. Given that, what strikes me is the apparently much more intense heat pulse of 2012 compared to 2011. If anyone here has actual knowledge about arctic water science maybe they could comment? Is this all to be put down to the latitude difference, or does it indeed show that the solar energy uptake in the upper layer in 2012 (in that region) is much more intense trhan in 2011? If so, can one based on that expect that the winter ice growth should be seriously retarded there? Can this lead to a kind of cross-seasonal memory effect, setting up strong melt season 2013 now already - or are winters there still strong enough to erase such differences?
Toggle Commented Oct 5, 2012 on PIOMAS October 2012 (minimum) at Arctic Sea Ice
real time current info - ocean currents - can be gotten here: http://www.oscar.noaa.gov/datadisplay/oscar_latlon.php (one has to generate ones own plotting to see clearly) yes it shows exactly what Andreas Muenchow just explained (focused Gulf Stream, then changing into a more broad flow field). there are strong anomalies apparently in the SST in the Baffin Bay and even in the Greenland stream but one shouldnt confuse an anomaly map with an actual stream map. The two branches of the north atlantic warm water inputting heat into the arctic (near spitsbergen and in the behindmost Kara sea) can actually be seen on the daily SST maps and they do show positive anomalies as well. I suspect if we talk about anomalous heat input into the artcic for this coming winter, from the ocean currents we should more focus on those two branches.
Toggle Commented Oct 5, 2012 on PIOMAS October 2012 (minimum) at Arctic Sea Ice