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crandles
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What Tilling and colleagues see in the data is a very strong link between autumn thickness and the degree of melting in a year. "You might think, for example, that wind conditions would be important because they can pile the ice up and make it less susceptible to melting, while at the same time exposing more water to freeze," the University College London researcher explained. "But we've looked at this and other factors, and by far the highest correlation is with temperature-driven melting." Am I following this correctly? If there is a lot of melt during spring & summer then autumn thickness tends to be thin. Err, yes I think I would expect that not only for the obvious reason but also because lower ice at maximum tends to cause more melt. Presumably there is something a little more subtle than that she is trying to get at?
Toggle Commented 4 days ago on In the meantime: CryoSat at Arctic Sea Ice
D has linked the Average for month the end of month figures are Day 151 31 May: 2014 20.288 4th lowest 2013 20.498 2012 19.591 2nd lowest 2011 19.483 lowest 2010 20.229 3rd lowest 2009 22.431 2008 22.878 2007 21.891
Toggle Commented Jun 3, 2014 on PIOMAS June 2014 at Arctic Sea Ice
>"Looking at the data I see that modelled volume reached 23,104 km3 on April 15th, which is slightly more than the 292,900 mentioned. Maybe the folks over at the PSC calculated the max differently." The average of the 30 days in April comes to 22.931 so I suspect this is a rounded monthly average rather than a single day maximum. Probably best not to expect too much accuracy at one day level so I would expect scientists to look more at monthly average than a one day max. Whether you use a monthly average or single day this is second lowest, above 2011 by about 0.42 or 0.427. So little difference. Shape of curve in April this year is unusually flat ending month at 3rd lowest. Not really sure why this is. Any ideas?
Toggle Commented May 8, 2014 on PIOMAS May 2014 at Arctic Sea Ice
If updating ASIGs, displaying piomas v2.1 and current year would be better; the image to display should be: http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1_CY.png Thanks for this and all the work you do.
Toggle Commented Apr 15, 2014 on PIOMAS April 2014 at Arctic Sea Ice
>"I thought it'd be a nice way to pass our time while we wait for the latest PIOMAS update." Which is now out 31 March 14 value 22.609 just below 2011 minimum maximum of 22.677, is second lowest for 31 March 14.
Toggle Commented Apr 7, 2014 on Research for a novel at Arctic Sea Ice
If the novel writer is looking for more learned comment Maslanik et al 2007 includes "The area where at least half of the ice fraction in March consists of ice that is at least 5 years old has decreased by 56%, from 5.83 * 10^6 km2 in 1985 to a minimum of 2.56 * 10^6 km2 in 2007. Most of the perennial pack now consists of ice that is 2 or 3 years old (58% in March 2006 vs. a minimum of 35% in March 1987). The fraction of 5+ year old ice within the MYI decreased from 31% in 1988 to 10% in 2007. Older ice types have essentially disappeared, decreasing from 21% of the ice cover in 1988 to 5% in 2007 for ice 7+ years old. The greatest change in age distribution occurred within the central Arctic Basin. In this area (region 1, Figure 1), 57% of the ice pack was 5 or more years old in 1987, with 25% of this ice at least 9 years old. By 2007 however, the coverage of ice 5+ years old decreased to 7%, and no very old ice (9 + years old) has survived. From 2004 onward, and in particular in 2006 and 2007, the remaining oldest ice has been confined to a small portion of the Arctic (regions 6 – 8); essentially a relict of the perennial ice cover of 20 years ago."
Toggle Commented Apr 7, 2014 on Research for a novel at Arctic Sea Ice
P-maker "The object will be frozen into the pack ice north of Svalbard and slowly drift towards the North Pole." Huh? From north of Svalbard or anywhere along Atlantic edge of ice pack which is likely south of Svalbard it is only heading one way with the Transpolar Drift towards the Fram Strait. Anyway as I mentioned above, Beafort Gyre has weakened recently so gyre was more likely to take object from north pole area towards Ellesmere.
Toggle Commented Apr 7, 2014 on Research for a novel at Arctic Sea Ice
>"The ice mass balance buoys that started near the North Pole this time last year emerged through the Fram Strait before Christmas:" Yes but the Beaufort Gyre used to be stronger than it has been recently. One or two trips round the gyre seems possible at up to about 8 years per loop, but probably wouldn't remain frozen either coming to top and melting in summer or sinking to sea bed. Getting stuck somehow in landfast shelf seems extremely unlikely but would allow a 200 year timescale. Stuck in a 20m ridge that tends not to move much is also unlikely but much more plausible than in a landfast shelf. I would imagine two or three decades might be possible before being dropped to sea floor or melted at surface during summer on a trip around the gyre. Polar bears can be inquisitive. Taking an object back to a den on land does not seem possible to me, but a transfer from a ridge near a landfast ice shelf to that ice shelf in autumn so it is then buried in snow and remains frozen might just be within realms of possibility. There have been a few videos posted of polar bears being inquisitive with remote control video cameras.
Toggle Commented Apr 7, 2014 on Research for a novel at Arctic Sea Ice
Re solar. http://www.ips.gov.au/Solar/1/6 forecasts peak was Dec 2012. Highest 2 months seem to be Nov 2011 and Dec 2013. A double peak or just negative noise for 2012 or might the peak be late 2013 or even 2014?
Toggle Commented Feb 13, 2014 on Looking for winter weirdness 2014 at Arctic Sea Ice
Hi, yes Gas Glo is me. Hope you and Neven didn't mind me sending you invites.
Toggle Commented Jan 10, 2014 on Looking for winter weirdness 2014 at Arctic Sea Ice
The White House is hosting Google+ Hangout discussion at 2 PM ET today with prominent scientists and meteorologists to discuss the "Polar Vortex" and how singular weather events play into the larger issue of climate change. They'll be taking questions using the hashtag #WeTheGeeks . We hope you'll join! says a comment on the white house video. However, judging by other comments there, I doubt it is worth trying to ask anything sensible. Any thoughts on why they are pedalling Dr Francis' hypothesis which has been questioned in the scientific literature and suggesting increased frequency to come when they could look at frequency of such cold temperatures as Jeff Masters did demonstrating much reduced frequency of these temperatures?
Toggle Commented Jan 10, 2014 on Looking for winter weirdness 2014 at Arctic Sea Ice
Jeff Masters' "Part of the reason that this week's cold wave did not set any all-time or monthly cold records is that it is becoming increasingly difficult to do so in a warming climate. As Andrew Freedman of Climate Central wrote in a blog post yesterday, "While the cold temperatures have been unusual and even deadly, climate data shows that intense cold such as this event is now occurring far less frequently in the continental U.S. than it used to. This is largely related to winter warming trends due to man-made global warming and natural climate variability." For example, in Detroit during the 1970s, there were an average of 7.9 nights with temperatures below zero. But this decade, that number has been closer to two nights." seems a little at odds with what was said by White House's Dr. John Holdren's (posted right next to the JeffMasters quote): "but a growing body of evidence suggests that the kind of extreme cold being experienced by much of the United States as we speak is a pattern that we can expect to see with increasing frequency as global warming continues." A septic might be driven to suggest that the warmists should get their story straight, is it increasing in frequency or decreasing? Of course it isn't actually a contradiction, the pattern could occur with increasing frequency but such low temperatures occur with reduced frequency. (It is just that reading and hearing them next to next seemed a bit strange.)
Toggle Commented Jan 10, 2014 on Looking for winter weirdness 2014 at Arctic Sea Ice
But http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2013&ui_day=365&ui_set=2 shows big snow extent negative anomaly in Europe
Merry Christpiomas to you all.
Toggle Commented Dec 23, 2013 on Merry christPIOMAS at Arctic Sea Ice
>"I was just surprised to see the level of disagreement about..." I wondered whether this was a case of journalists not knowing how to deal with science stories other than to either make it into lone scientist fighting long battle against consensus view or to make a disagreement out of it in order to present both sides. Reality might be more like some don't regard it as well established, at least not yet.
Re " I should've worded that better as I didn't mean to imply that what we saw happen this year was a negative feedback due to low NH snow extent." We might speculate that ice cracking in February like it did in Feb 2013 is a negative feedback. This seems likely (also cracking in April is likely to be positive) but I would suggest it is still just speculation rather than established.
Toggle Commented Nov 28, 2013 on And the wind cries methane at Arctic Sea Ice
Quote: "noted how a lot of models predict that a combination of Arctic sea ice and land masses that become snow-free earlier and earlier in spring, could lead to more cyclonic activity in the Arctic. As we saw this melting season, it could be a negative feedback preserving more sea ice but we learn now that .... Every advantage has its disadvantage, it seems." I don't think this is right. Snow cover this April was, given the trend, unusually high and little sea ice was melted whereas previous years had low ice in April and high sea ice melting. (It is less clear if you look at May or June.) I don't think you can suggest a feedback from 1 years data. I think it is pretty logically safe and previously established that it is a positive feedback not a negative one. So it is bad in both ways though I don't think either is particularly surprising.
Toggle Commented Nov 27, 2013 on And the wind cries methane at Arctic Sea Ice
Was the error calling 'Severnaya Zemlya', 'Novaya Semlya'? A bit of confusion with the banana shaped 'Novaya Zemlya'.
Sourabh, The first formula "Snow + Extent - (Extent - Area)" made me think you end up cancelling the extents and are just left with just two factors snow + area. However with different multipliers for the three factors, the extents do not cancel precisely and the reason for this split is in the explanation of the factors: "For (3): 1.0 (assuming that ALL solar radiation onto melting ice and into polynia will cause ice to melt later in the season. For (2): 0.5 (assuming that half of the heat absorbed in the ocean OUTSIDE of the main pack will cause ice melt (while the other half would cause the ocean to warm up." In a polynia, whatever direction the wind and water current, heat moves towards ice. Outside the pack, 50% of time wind and water current move heat away from the ice. This reasoning makes for more sophisticated analysis than just using snow + area where snow + area does make more sense than snow + extent. Note also that the extent ends up as a negative factor.
Toggle Commented Jul 2, 2013 on Problematic predictions 2 at Arctic Sea Ice
Great work Rob. Rutgers snow cover for June is 6.01 well up on 2012's 4.8 (or .2 more than 4.8? that you used?). I am not sure what numbers you used. Should it be average snow over June or last week of June or average of April, May and June? Similarly did you use numbers for extent and area at the end of June or average for month? (Also which extent record?)
Toggle Commented Jul 2, 2013 on Problematic predictions 2 at Arctic Sea Ice
>"On the comments regarding a protective arm of MYI towards the Pacific: I don't get it." Agreed that inflow generally isn't at the surface but what has this to do with it? Surely surface can and does circulate more clockwise than anti-clockwise with Beaufort Gyre regardless of what inflow waters are doing at below surface level. Beaufort melts out but by end of January: http://www.aari.ru/resources/d0015/arctic/gif.en/2012/20120131.GIF vs http://www.aari.ru/resources/d0015/arctic/gif.en/2013/20130129.GIF However, I don't think that is doing recent movement well: http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictnnowcast.gif is more like it showing lots of thicker ice off Banks Island but not much north of West Alaska/Bering Strait.
Toggle Commented May 13, 2013 on 2012/2013 Winter Analysis at Arctic Sea Ice
Foot soldiers? Buckets and spades? We need to boost our economies with the production of laminated tin foil or something similar. Install with South facing slats so most snow falls through it but sunlight gets reflected .... Also apply to roof space to reflect back to space (or towards nearby solar panels). In fact why start with Greenland, start with dark areas eg above black tarmac roads ... ;)
>"(although, contrary to the other graphs, it doesn't seem to be updated all the way to the end of the month):" If you look at Jan then it is clear the marker is at the middle of the month (and it is the same with their volume graph). So end of April is the midpoint between April and May markers and both graphs therefore appear to run to April 30.
Toggle Commented May 4, 2013 on PIOMAS May 2013 at Arctic Sea Ice
http://www.aari.ru/resources/d0015/arctic/gif.en/2013/20130423.GIF still doesn't show much old thick ice in Beaufort. I think this is wrong with the other sources all agreeing that a big area of old thick ice has moved towards Beaufort. Early in the season it seemed there was very little thick ice there. Now it is looking like a thicker swathe than usual at least on the eastern side. Alaskan edge has little. If that keeps drifting that way, this melt season might avoid records but leave the ice in a terrible state for 2014.
Toggle Commented Apr 29, 2013 on 2012/2013 Winter Analysis at Arctic Sea Ice
http://www.bbc.co.uk/news/science-environment-22167675 reports “The European Parliament has rejected a plan to rescue the EU’s ailing carbon trading scheme. Members narrowly voted against a so-called “backloading” proposal that would have cut the huge surplus of allowances currently being traded. Because of this excess, the price of carbon on the EU Emissions Trading Scheme (ETS) has plunged to less than 5 euros a tonne. But opponents won the day by arguing the plan would push up energy costs. The price of carbon once stood at 32 euros per tonne.” That article has now been extended. Where now? Doubt the committee will propose a carbon tax instead.
Toggle Commented Apr 16, 2013 on Perception of the Arctic at Arctic Sea Ice