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Maryland, Between DC and Baltimore.
Steve Coulter. Amateur arctic cryophile. Email: SteveMDFP -at- gmail -dot- com
Interests: Climate, medicine, addiction medicine, Doctor Who, progressive politics. Writing, when the spirit moves me.
Recent Activity
My sense is that this new map may well be showing reality, more or less. My sense is that it's pretty darned difficult to assess how thick a given area of ice is. But the PIOMAS numbers are certainly treated pretty seriously. I note that the PIOMAS chart on the bottom-left corner of Neven's Daily Graphs page is unlike most other graphs in this field-- the bottom of the Y-axis really is ZERO. And the curve right now is pointing toward ZERO and not all that far above it. The remaining few million km-squared of sea ice is terribly thin and fragile, and not able to influence arctic climate conditions nearly as much as the old normal. I'd say that in terms of any functional significance of arctic sea ice, we are ALREADY at a functionally seasonally ice-free arctic.
Toggle Commented Aug 11, 2012 on New site with new thickness maps at Arctic Sea Ice
Rob Dekker wrote: "The upwelling from 200-500 meter all the way to the surface, recorded simultaneously on two different ITPs (and coinciding with a known and significant storm overhead) is, as far as I can see, unprecedented in the ITP record" Quite so. And I think this can be perhaps understood as a consequence of widely fragmented ice in the arctic. Wind is plainly driving this ocean mixing. The current state of fragmented ice perhaps ENHANCES the ability of wind to create mixing. Due to Coriolis forces with Ekman pumping involved, any lateral movement of surface water promotes mixing with deeper waters. When the arctic is largely a solid, immobile ice sheet, wind cannot transfer momentum to the water. In ice-free water, wind has to kick up some waves to be able to transfer momentum to the water. But when fragmented floes are present, each irregular piece of ice acts as a sail in the wind, so the wind transfers momentum more readily to the surface. And each piece of ice, being 90 percent submerged, quite effectively transfers that momentum to the water. With winds moving in essentially a single direction in any given area, vast volumes of surface water are more readily put into motion. The difference in motion between the surface and deep water inevitably creates mixing. It's a positive feedback mechanism, not for climate, but for destruction of sea ice. The thinner and more fragmented the ice, the more readily wind creates mixing, which makes the ice thinner and more fragmented. Until, that is, the ice is gone.
Toggle Commented Aug 10, 2012 on Arctic summer storm open thread 1 at Arctic Sea Ice
Apocalypse wrote: The blog link is: If anyone here hasn't seen this page, please look. The sea ice thickness images for the arctic look simply horrifying. I'd be interested in anyone's comments. Visually, it looks like the arctic, in terms of volume of ice, has simply collapsed.
Toggle Commented Aug 10, 2012 on Peeking through the clouds 3 at Arctic Sea Ice
Artful Dodger asked a great question about what this storm might mean for methane release. Dabize's contribution is an interesting thought. There's a rather interesting article on arctic methane here: The maps there make me wonder if the "Laptev Bite" might indeed correspond to a methane hot spot. I'm a little skeptical that GAC-2012 has enough power to disturb sediments (though much of the East Siberian shelf is pretty darned shallow. Regardless of sediments, though, methane solubility does increase with depth (pressure), and waters overlying those sediments are apparently saturated with methane in solution. Dekker pointed out that ocean mixing is occurring to a surprising depth with this storm. If deep waters saturated with methane are carried closer to the surface, that methane tends to come out of solution, like CO2 coming out of sparkling water. I'd expect that big methane releases are already happening with this storm.
Toggle Commented Aug 9, 2012 on Further detachment at Arctic Sea Ice
All, As I step through the forecasts at (N-Hem, 500hPa,SLP), it projects GAC-2012 to drift over the Canadian Archipelago and dissipate. However, it shows it being replace by a couple more strong cyclonic systems in the area, dipole anomalies and similar disturbing features for the health of the ice. In particular, the current remaining thick/concentrated ice seems to be gathering above the Fram Strait. Evolving pressure gradients look like they'll favor strong export out the Fram in the coming days. Could be a one-two punch for the remaining ice volume. At the moment, O-Buoy #4 is in the Strait and has stopped moving south. When it resumes, it will probably take a lot of other ice with it. See: Parenthetically, I find it fascinating that the buoy's motion in the strait seems to be strongly affected by tides. At least, I think the odd periodicity of movement must be tidal-related. I don't know if this has been observed previously. Sigh. Small consolation, for the betting crowd. Intrade has 50-50 odds on whether a new sea ice extent record will be reached in September. Looks like easy money to me: -- Steve
Toggle Commented Aug 8, 2012 on Arctic storm part 3: detachment at Arctic Sea Ice
As far as naming, I like R. Gates' description, "the Great Arctic Cyclone of 2012." GAC-2012 is a good name. I'm wondering if this might be a feature of the "new normal" for the arctic. Looking at the weather map from, I'm struck by the sudden organization of weather systems. A few days ago, we had a patchwork of high and low pressure systems. Now it's all self-organized into a central cyclone surrounded by high pressure systems, presumably feeding warm/moist air into the central cyclone. I wonder if we could be witnessing a new kind of stable cyclone (as the Red Spot of Jupiter is a stable cyclone). Until colder temps around the N. hemisphere develop to shut off the heat engine, that is....
Toggle Commented Aug 6, 2012 on Arctic storm part 1: in progress at Arctic Sea Ice
Alberto Silva, et al, That chemistry equation may be technically accurate, but doesn't convey the proper implications for CO2 flux. Those two bicarbonate ions most likely started out as CO2 in the atmosphere. The CO2 molecule on the right is likely to combine with H2O to form carbonic acid in solution, as this is all in an aqueous medium. The calcium carbonate has a fair chance of becoming ocean floor sediment in the end. Thus, the formation of calcium carbonate is a net carbon sink. I don't think this is much of a climate feedback at all, because these plankton thrive best where there are other nutrients, and this tends to be in colder waters. When the surface waters of the arctic become warmer than the deep waters all year round, then delivery of oxygen to the deep oceans will stop, and we'll be facing another Permian Extinction. [Ocean life] "died from a lack of dissolved oxygen in the water, an excess of carbon dioxide, a reduced ability to make shells from calcium carbonate, altered ocean acidity and higher water temperatures. They also concluded that all these stresses happened rapidly and that each one amplified the effects of the others."
Actually, I think it's better than "as good as open." Even if McClure Strait itself is blocked by ice, that extremely narrow channel to the "left" of McClure Strait is "Prince of Wales Strait," according to the map at;0.532550;1.012468/Arctic-Map I think that counts.
Toggle Commented Jul 31, 2012 on Northwest Passage as good as open at Arctic Sea Ice
Seke Rob, I've noticed that when transport out the Fram Strait is brisk, almost all the polar ice moves in that direction, judging by motion of the drift buoys--their trajectories are roughly parallel to each other. This drift map separates the last 10 days of motion from the rest of a 60-day track. Yes, the past week or so has seen a big drop in transport out the Fram. If/when the weather again favors transport out the Fram, the more mobile ice may now move more quickly. See:
Paul Klemencic Thanks so much for your contributions here. I think you've presented an excellent synthesis--pulling together disparate mechanisms and findings that individually result from analysis of data. It seems to me that the only way sea ice could fail to fall below all-time records is if arctic weather remains ideal for ice preservation -- weak, diffuse low pressure with clouds and mild winds. Any deviation from this (intense lows, significant highs, any strong winds in any direction at all) will drive the thin, fractured, vulnerable ice to melt.
Bob Wallace, Thanks for the fascinating contribution. It seems 1889 was a very odd year of weather. I found this interesting: "This past March was the second warmest winter month ever recorded in the Midwest, with temperatures 15 degrees above average. The only other winter month that was warmer was December of 1889, during which temperatures were 18 degrees above average. Now, MU researchers may have discovered why the weather patterns during these two winter months, separated by 123 years, were so similar...."
Janne Tuukkanen-- That's an interesting point. But the isobars are (roughtly) circular. Judging by clouds at least, winds around low pressure areas seem to be spiral. Thus, there may not be a contradiction between ice moving at 45 degrees to the right of the wind, and the ice moving parallel to isobars. Now, it may get more complicated for wind and ice when movement is in the middle of a dipole anomaly, I'm not sure....
Toggle Commented Jul 25, 2012 on Peeking through the clouds at Arctic Sea Ice
To all here-- What a fabulous discussion!! The education we are stimulating for each other surely compares favorably with a grad-level seminar course. One small conclusion. I think with the forces we're discussing (low pressure systems tending toward divergence, Ekman pumping, etc.) we have an explanation for the macro-level observation that dramatic arctic ice loss is paradoxically accompanied by a preserved sea ice extent. That is, while the ice sheet is largely solid, an atmospheric low is unable to scatter arctic ice. Under thinner ice conditions, we don't have immobile sheets of ice, we simply have floes packed next to each other. These move in response to the wind, and are spread centrifugally through complex geophysical forces whenever a low pressure system passes. Global warming deniers are fond of pointing out how relatively normal sea ice extent remains, even as ice mass and even ice area decline. The preservation of sea ice extent is NOT a reassuring indicator, it's reflection of the arctic ice sheet becoming like an ocean of slush. Quite obviously, as sea ice become thinner and more dramatically spread out, it becomes more vulnerable to catastrophic melt, not more resilient.
Toggle Commented Jul 24, 2012 on Peeking through the clouds at Arctic Sea Ice
SteveMDFP is now following Neven
Jul 22, 2012
Apocalypse-4Real-- Those buoy readings are eye-popping to me. Temp readings on the buoys I've been checking seem rarely to go above 2 dC (O-buoy and army bouys shown on Neven's daily graphs page). You've got one showing 6 and 7 degrees in air well north of the Nares straight, and this one shows water temps at 2.7. I gather that the buoys I've looked at have their thermometers quite close to the ice, thus rarely straying far from O degrees. And they won't then stray far from it until they're floating in open water. With this much warmth above and below the ice, and plenty more warmth in the air and waters all around the arctic, I'd say we're in store for a lot more melting. I think we saw a report here about an icebreaker reporting the polar ice to be just 60 cm thick. I can't see how much of it will survive the rest of the summer.
Toggle Commented Jul 22, 2012 on Peeking through the clouds at Arctic Sea Ice
Al Rodger, et al The further drop in albedo in Greenland is definitely worrisome. It does coincide in time fairly closely to the drmatic drop in "Radar albedo" that my animation shows. But I'm inclined to think that they are very different processes, but both related to melt of snow and ice. I'd chalk up the optical albedo increase probably mostly to soot from the fires in Siberia. The've been massive, with astounding amounts of smoke visible in the top-right photo in the arctic mosaic (r06c06) for essentially a whole month. Winds have consistently carried this northward (and eastward). The smoke has altered ozone levels as far as British Columbia. The radar "albedo" increase, I suspect, cannot be explained by soot on Greenland -- too sudden, and sooty material previously prominent on the ice sheet doesn't seem to show on radar--though the resolution of the radar images is too poor to make this statement with confidence. Meanwhile, the bright radar line seems to be reorganizing in Greenland, farther inland. I have to think that this represents a border between freezing and melting of melt and runoff.
Toggle Commented Jul 18, 2012 on The wet side of Greenland at Arctic Sea Ice
Al,'s from the ASCAT images, you get to them from Neven's "daily graphs" page. Then "Radar images of the entire Arctic from the EUMETSAT METOP satellite." From here, you scroll down to the Northern Hemisphere images. The ten images in the animation start with "msfa-NHe-a-2012186.sir.gif" So, by label, days 186 - 195. Date stamps are July 6 - July 15. One more image has been added since I put this together last night--no major change from the final frame. It's a massive, sudden landmass-wide change in the radar images. Not much to see on the optical MODIS pictures, though. Figuring out exactly what we're looking at is the interesting task. Until now, every radar image of Greenland I've seen has shown this dramatic bright ring around the entire landmass. The southern rim of this has shifted northward some over time, but otherwise seems quite stable, until now. To my mind, we have to be looking at a dam of ice just under the snowcover that circles the landmass--what else could be more reflective than bare rock? It's probably only so bright when the top surface is flat horizontal, perpendicular to the radar signal. It then disappears from the image not because it's all suddenly dissolved, but because the top surface of this ice is no longer smooth, flat, and perfectly horizontal. Slush and meltwater must have built up just inside of this vast circular dam. With warm temps and increased melt, the ice dam gave way in the south, and then the shockwave either travelled clockwise around the whole circle, or maybe shockwaves travelling through the ice mass caused collapse all the way around. If I'm right about this, folks on Summit Camp should have heard or felt something dramatic, even though they're far away from the presumed ice dam. It would have been about the 12th, I think, that it would have been most noticeable. Given the extent and speed, I'd think seismographs in Canada and maybe Iceland would have picked up something. The initial break in the south was relatively far from the coastline, so actual release of meltwater at the coast should have been almost simultaneous all around the whole coast of Greenland. Like I said, when I put the animation together and watched, I was totally floored. And to think that there's so little to see on the optical images. Amazing.
Toggle Commented Jul 16, 2012 on The wet side of Greenland at Arctic Sea Ice
One commentator on this blog mentioned that there'd been a big change in Greenland's appearance on the radar ASCAT images. I've puzzled over how to interpret these. So I decided to take the last 10 days and put them into an animated clip (my first animation effort, I have a ways to go to match Neven). The results blew my mind and caused me to think the changes could relate directly to the sudden flooding... Visually, the sudden change we see looks as though some internal ice dam in the ice sheet suddenly gave way and blew out the southern tip of the high-reflectance border. As though a balloon popped at the very bottom. It also looks like some outflow went out the KIV Steenstrups River. I'll try to clean up this animation, but I wanted to share it right away: Steve Coulter
Toggle Commented Jul 15, 2012 on The wet side of Greenland at Arctic Sea Ice