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Allen W. McDonnell
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Which weather system is the one that causes higher transport out through the FRAM strait? For some reason I can never keep straight which formation has what general effect.
Toggle Commented Apr 8, 2016 on Beaufort under early pressure at Arctic Sea Ice
Neven a quick question, I have been looking for information on the retreat of the Petermann ice tongue with very little success and also for information on the big tabular iceberg that broke off of Ellesmere island a couple years ago and then became grounded on the beach later that year. The graphic someone posted over on peak oil dot com looks like a big tabular berg breaking loose and drifting westward from Ellesmere. Google has not been friendly looking for these things, it keeps directing me to Jakobshaven for Greenland and Antarctica when searching for Arctic Ice Shelves. Any pointers would be greatly appreciated, TIA! [There have been some problems since yesterday with logging in on Typepad, and so I'm doing an inline response. Allen, if you check out this blog's Glaciers category you might find some more info on Petermann (I've written several blog posts over the years). As for that big tabular iceberg: Are you referring to the break-up of the Ellesmere Ice Shelf that was in place for 3000-5500 years? Neven]
All of these long term future models use the current three atmospheric cell model to predict weather and climate. However if an ice free Arctic Ocean flips us over into the one cell atmospheric system that existed 5 Million ybp like we had the last time CO2 levels were this high the changes would be profound and very rapid. I believer that long before we reach 2100, and possibly before we even reach 2020, we will pass the tipping point where the Arctic ocean is ice free for at least the summer. When that happens the intense warming caused by the extreme decrease in albedo reflectivity will flip us into a one cell northern hemisphere weather system. The cascading effect of that will be above freezing temperatures around Greenland 24/7/365. Just how long can the GIS last in 2C temperatures for a long period of time? Right now there are only two or three weeks when it is even possible for the entire GIS to see air temps above freezing and it is melting at an accelerating rate, multiply that to 50 or 52 weeks a year and the GIS will collapse extremely rapidly compared to all the model projections. See http://www.fields.utoronto.ca/programs/scientific/10-11/biomathstat/Langford_W.pdf
Toggle Commented Mar 19, 2014 on PIOMAS March 2014 at Arctic Sea Ice
While the winter snow cover would be an increase in albedo during sunlight during the dark winter it acts as a nice fluffy insulation blanket that keeps the cold from penetrating the ground as easily. That should mean that once the sun come over the horizon and melts that fluffy snow the ground and ice under the snow will already be closer to the melting point than it would have been if the ground were bare. Here in Ohio we have been in cycling states switching back and forth between the warm rain we have today with +7 C temps and the two to four week periods of -15 C or colder. We have had huge piles of snow piled up and then they all melted in December and again in January. Today they are melting once again and the snow season here usually lasts at least another month. The ten day forecast says we will be getting more snow in about 5 days with temps from -5 C to - 20C. Our normal for this time of year highs of +2 C with cold nights allowing the snow pack to gradually fade. Instead we are under our third flood warning of this winter.
JackTaylor, here are a couple I grabbed this morning, if you Google it yourself you have to sort out the sources that present scientific data from the headline writers who often use the most extreme terminology to get more clicks on their websites. Even National Geographic went overboard earlier this year by using the most simplistic model and then reporting the results as if they were significant. During the PETM, the Paleocene-Eocene Thermal Maximum 56 million years ago and all earlier world greenhouse events the temperature of the planet has always hit a hard limit when the climate was in the hothouse. Carbon Dioxide consistently shows a temperature increase of between 2C and 4C for each doubling of content. Taken to the greatest extreme you can go from 280 ppm (pre-industrial) to 560 ppm and get 4C rise, then from 560 ppm to 1,120 to get another 4C rise, and if you burn everything with fossil carbon we can get our hands on you might just barely double it one more time to 2,240 ppm giving you a total of 12C maximum rise. Of course the three doublings might also only give you 6C rise on the low end. Most climate scientists will give you the 6C-12C range for burning just about everything burnable. Recent observational studies show that these effects almost balance, but that the cooling effect is somewhat more important. From the point of view of global change, however, it is crucial to note that this small difference is about five times larger than the radiative effect anticipated from a doubling of atmospheric carbon dioxide (CO2), and that the individual components of the difference are orders of magnitude larger. In existing climate models about one third of the predicted warming due to increasing CO2 arises because of the predicted cloud changes. These predictions, however, are highly speculative because none of the models include interactive cloud physics. from http://cgcs.mit.edu/research/focus-areas/convection-atmospheric-water-vapor-and-cloud-formation/ and The previous extreme global warm-up happened 56 million years ago, when Pangaea was splitting into separate continents. It is suspected that huge amounts of carbon were released into the atmosphere and oceans in the form of carbon dioxide and methane. The globe warmed 5 to 9°C (9 to 16°F). Most ecosystems were able to adapt—tropical mammals migrated to North America and Europe, and sea life swam poleward to cool down. But the rate of warming during the PETM pales in comparison to what we're now experiencing. Today, global temperature could be warming at a rate that is too fast for ecosystems to adapt. from http://www.wunderground.com/climate/PETM.asp?MR=1
Toggle Commented Sep 11, 2013 on PIOMAS September 2013 at Arctic Sea Ice
Mdoliner43, The reduction in the albedo of the Earth from the loss of the ice is of greater magnitude by quite a large extent than the long wave radiation escaping into the atmosphere. There is an upper bound on global warming from water vapor condensation effects, when water evaporates from the surface it takes a lot of energy with it, when the water vapor condenses into droplets at high altitude it releases that thermal energy as long wave radiation. Because the condensation takes place at relatively high altitude the thermal energy released has an easier time escaping because a large portion of the greenhouse gasses that reflect long wave radiation are below the condensation layer. Because of this energy convection effect so long as Earth has surface water to evaporate and condense at high altitude there is a limit to how warm the surface can get.
Toggle Commented Sep 9, 2013 on PIOMAS September 2013 at Arctic Sea Ice
If you go to the interactive graphing page on Cryosphere Today http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html and turn off all the years except for 2009 and 2013 you will see that for the last 17 days the two lines are very nearly parallel. If this holds for the rest of the season we will end up below 3,500,000 km^2 Sea Ice Area, which is nothing to cheer about. Sure it would leave us a million km^2 higher than 2012, but most people agree 2012 was an outlier year, a much steeper drop than projected. Perfect beginning of the season coupled with a late season storm that scattered fractured thin ice into warm surface waters is pretty much the definition of a perfect melt year. Until 2006 every year ended the melt season with more than 4,000,000 km^2 of residual ice, since then the best year was 2009 with 3,424,600
Toggle Commented Aug 21, 2013 on ASI 2013 update 7: cold and cloudy at Arctic Sea Ice
Volcanoes are scattered all over the surface of the Earth, not just in the low latitudes. They often but not always follow plate boundary lines and they exist as a result scattered over Antarctica, New Zealand, South America, Alaska, Siberia. Some are isolated peaks deep within the continents themselves like the San Fransisco Volcanoes of Arizona or Yellowstone Caldera in Wyoming. Mount Forel in Siberia is the largest known Shield Volcano on Earth, it is like the set of four giant shield volcanoes on Mars, Olympus Mons and the three Tharsis Montes.
Toggle Commented Aug 21, 2013 on ASI 2013 update 7: cold and cloudy at Arctic Sea Ice
How badly broken up is the MYI if you can detect waves passing through it? We know from what took place when the Larsen B shelf disintegrated that any time floating ice breaks it rolls until the mass is stable buoyantly. What I mean is, if the ice is 4 meters thick and breaks off in a 3 meter wide segment it will roll over sideways so that it is then 4 meters wide and 3 meters high. The thinnest dimension naturally gets arranged as the vertical dimension. The same thing is true of icebergs far out to sea, as they melt they will roll so that the thinnest dimension is always vertical. If 20 meter thick very old sea ice is being broken into smaller than 20 meter pieces the same thing will take place, which will give the appearance of greater area and extent even if the volume is static. The reality is however that the less than 20 meter pieces rolling over will end up as 20 meter wide pieces of less than 20 meter thickness so they will melt easier.
Toggle Commented Aug 21, 2013 on ASI 2013 update 7: cold and cloudy at Arctic Sea Ice
If it were up to me funding would be put forward to intensively study the switch from three cell climate systems to one cell system to try and determine just how near the tipping point we really are right now.
Based on the data available on the Cryosphere Today website as of year day 227 the Arctic Sea Ice Area is lower than 1999 and all the years before that back to 1979 that have satellite records. Even if melting stopped today (17AUG2013 as I type this)the level of ice remaining should be troubling, and I strongly suspect the melt will still continue for another two or three weeks at a minimum.
Toggle Commented Aug 17, 2013 on Perception of the Arctic 2 at Arctic Sea Ice
Personally I have always thought the 15% or more standard is a bit odd, I would think 45% is a much more logical place to pick for rounding up or down than 15%!!! If you went back through all the gridded data for the last 34 years of the satellite record and calculated everything from a 45% standard I bet things would look even worse than they do today. It made some sense early on because a grid area with 15% ice meant a ship passing through had to navigate a little cautiously to avoid risking damage. Today I don't think that is a major concern when so much of the area is down right open water but obviously the major research organizations do not agree with me. Using the 15% standard the entire Arctic ocean could be a giant slushy with 20% ice per grid point and it would show on the records as 100% ice/extent--area. Then a few days later it could drop 6 % to 14% average and suddenly it would be classified as ice free. This makes no sense to me.
Toggle Commented Aug 12, 2013 on Third storm at Arctic Sea Ice
Jenny, best advise update the numbers in the story right before you submit it for publication with a projection of what could happen by the end of the season. Make sure you are broad enough in your prediction that people can't point and laugh so that next year they might ask you back for a new article. Something like it could end up as high as X or as low as Y where both are possible numbers. So long as the actual result Z falls between you look wise and cautious, if Z if above X or below Y you don't look nearly as good.
Toggle Commented Aug 10, 2013 on Third storm at Arctic Sea Ice
Pete think of it this way, any fresh water ice floating in sea water is 7/8ths submerged. Therefore your 10 meter high sail is attached to a 70 meter deep hull and isn't going to do much too it. By the same token your 2 meter thick first year sea ice has 25 cm sticking up above the water line, which is low enough that wind blown spray off the surface of the ocean gets splattered all over it. The thin ice gets the double whammy, not only are shallow waters melting it from below, spray from the storms encourages melt from above as well. Once the thin layer of melt fresh water is thoroughly mixed in the water spray is also salty, though the latent heat it carries is the biggest effect.
Toggle Commented Aug 10, 2013 on Third storm at Arctic Sea Ice
One of the things people seem to be forgetting is a storm like this pretty much does away with the surface fresh water layer. The storm stirs things up pretty thoroughly mixing the fresh layer into the lower layers and all but eliminate the fresh on the surface. Two side effects, the saltier water is a little warmer so it transfers heat to the shattered ice, and depending on how well mixed it ends up without a fresh water skim on the surface freeze up is much slower to start and extend because it takes several degrees colder temperatures to freeze over.
Toggle Commented Aug 9, 2013 on Third storm at Arctic Sea Ice
I find myself wondering what a nice warm rain thunderstorm like those that have recently pounded the eastern USA would do to all that thin ice in the Arctic. Even rain that feels cold to a human would add a lot of thermal energy directly to the ice and to the water it is floating in, and being fresh water it would stay on top for a while before it mixes into the sea water.
I must admit I have been very surprised the last four days, I though the storm would raise things up for maybe four or five days and then extent and area would both crash. So far they have both been bobbing around without much change from day 204 to 214 they have bounced around between 4.795 4.877 SIA. I thought we would be hitting 3.900 by now when I was looking at the imagery two weeks ago. Neven I have to hand it too you, your call was much better than mine.
@ Aaron Lewis Ice sheets are under massive compression and the basal layer is very plastic, it deforms to fill any gaps in a short period of time. This has even been demonstrated experimentally by drilling ice caves deep into the ice with steam lines and then observing the way the ice deforms to fill the air space back in within a couple of days. @ Robert S. The Moulins form only in the melt zones and the highest part of the sheet usually doesn't have any of them in evidence. If you dump melt water on the GIS in 1975 it would refreeze very quickly. Even in those cases where the water did find a crevasse and drop down into the ice sheet the surrounding ice was so cold the melt water would refreeze long before it made it to the base of the sheet. However as this process continued summer after summer the melt water transmitted an enormous quantity of thermal energy to the deeper ice, bringing its internal temperature much closer to zero C in the process. A decade or so ago it got close enough that melt water entering the glacier was no longer refrozen before it reaches bedrock. Now it flows along the bottom lubricating the area between its entry point and where it exits closer to the sea. By the time it travels that distance it has passed under thinner and thinner ice, by the time it gets to the edge the thin ice there doesn't need much pressure for the water to escape and it acts like any other river or stream.
@ Pete, I think what he is trying to say is the ice where they put the GPS tracking tower was frozen all the way to the base and not moving when they first set it up. In the last five years melt water has penetrated all the way to the base in that area and it has started moving, gaining a couple percentage points of speed each melt season since it became unstuck. I have seen similar remarks from other researches on the GIS, not sure if they are anywhere near this location though.
Long lecture by Jennifer Francis Phd. at the climate summit 2012 http://www.youtube.com/watch?v=RtRvcXUIyZg and this year 2013 http://www.youtube.com/watch?v=xugAC7XGosM I found her lecture's to be both informative and persuasive. Be prepared for a long listen if you want to hear the whole thing, I watched it a couple months ago while doing a long workout and it still wasn't done when my timer ran out so I had to finish it later lol. The 2012 lecture is about the Arctic Paradox, the second is about Sea Ice and Jet Stream dynamics.
Toggle Commented Jul 30, 2013 on Second storm at Arctic Sea Ice
Dorlomin asked for a definition of Hothouse climate so after giving it some thought I came up with one of my own. Hothouse climate [to me] is when the year around weather never decreases below 0 C degrees as the yearly average in a polar hemisphere of the Earth. I think it is necessary to specify it refers to a polar hemisphere because Paleoclimate data demonstrates that the northern hemisphere remained ice free year around as recently as 2.5-2.8 Mya based on the recently published Lake El'gygytgyn core data. Up until that time the northern hemisphere was in a permanent thaw situation instead of the permafrost climate that existed there for the last 2.5 Million years. During the period from 28 Mya to present we are certain Antarctica has had a large quantity of ice sheet coverage, so clearly the southern hemisphere was not in the Hothouse climate regime. We have evidence of periodic Antarctic ice going as far back as 34 Mya. If you pause and think about that for a minute you will see that Antarctica went through a series of freezes and retreats similar to the Canada/Scandinavia/Siberia glaciations of the last 2.8 Million years in the Northern Hemisphere. Perhaps if Humans had not come along when we did the North would have gone into a permanent freeze in a few million more years as global CO2 levels gradually declined from weathering in the Himalaya's and other mountain regions. In any case if the Arctic continental shelf methane all burps out over the next century or so it will be just a blip on the graph of all the warning gasses humans have added to the planet since the beginning of Agriculture. If enough comes out at once to take up all the OH radicals in the atmosphere the Ozone layer will backstop the situation as the methane gradually rises into the stratosphere.
Toggle Commented Jul 30, 2013 on Arctic time bombs at Arctic Sea Ice
I have so many newbie questions: how long do you think it will take before the tipping completes? What is THC? Why is ridging on the 500Mb level where the action is now? What exactly is ridging on the 500Mb level? A new thread on this topic would greatly be appreciated. Short answer, the tipping point could take as little as a decade or as long as a century. THC is the Thermal Haline Circulation aka Gulf Stream that flows up past Greenland and Scotland and is now extending further and further into the Arctic Basin. There is an under sea ridge that traps cold bottom water in the Arctic Basin, since the ice ages began this water has been to a large extent trapped and stagnant. The 500 mb level is IIRC where the Jet Stream, both Tropical and Polar, are formed. It refers to the altitude in the atmosphere where that air pressure level is reached. If I got that wrong someone will stomp on me pretty quick. The Jet Streams form where the three cells of each polar hemisphere come in contact, the Polar Jet is where the Polar Cell and Ferrel cell collide and the Tropical jet is formed where the Ferrell Cell and Hadley Cell collide. I believe the ridging he is referring too is the way the jet stream is being distorted north and south from its expected west to east track.
Toggle Commented Jul 29, 2013 on Second storm at Arctic Sea Ice
You are welcome, now you can share my bad dreams lol! All my life I have been fascinated by the environment and paleoclimate because like most kids I loved the heck out of dinosaurs and studied up on the climate they lived in. Tanada over on Peakoil.com posted the first of those two links on the Greenland thread over there and when I saw it I did some searching and found the second link. I shared both of them over here because I thought you would all be interested. The idea that the Earth existed in a dual climate state with the north in the Hothouse while the south was in the Icehouse never really clicked with me until I read that first link. I mean I knew the Icehouse in Antarctica started around 34 Million years ago while the Greenland ice sheet formed much later, but I never really thought about what it meant that Greenland was ice free up until 3 to 5 million years ago. Clearly based on the fossil remains the North was in a cool phase of the Hothouse climate until 5 Million years ago and possibly as late as 2.8 Million years ago. Think about that, the Earth was in two different climate states North and South for at least 25 Million years! Reading that first link made the two state Earth system really pop out at me, and as someone said up thread it makes all those climate models people have been using obsolete. If the North was in the Hothouse while the south was in the Icehouse, and we know it was, then all those climate models showing equal distribution of climate change are pure fantasy. The North will be back in the Hothouse very soon if nothing else changes, and at that time the South will still be in the Icehouse. That means it doesn't take 4C of temperature rise to flip the whole planet to the Hothouse, it takes 1.5C or so to flip the North, then another 3C or maybe 4C to flip the south. The whole UN set of negotiations based on 2C is completely invalid, by the time we officially hit that we will have tipped over the North into the Hothouse.
Toggle Commented Jul 28, 2013 on Second storm at Arctic Sea Ice
Villabolo, There are several competing factors all adding into positive feedback scenario's at this point. Around 5 Million ybp and before the Arctic ocean was ice free year around and the currents flowed in a Mediterranean pattern, warm surface water flowed in through the North Atlantic gaps, swirled around in a counter clockwise direction and at least in summer evaporated off enough water vapor that the surface waters because dense warm but highly saline water that would sink into the deepest part of the basin near the Beaufort sea, then escape as a bottom current back into the north Atlantic as the Mediterranean does through Gibraltar Straits today. The Gulf Stream is encrouging further each year on this pattern, if the trend continues the old system will reassert itself keeping warm water entering and preventing freeze up of the surface even during the polar night. We have already hit the 400 ppm mark as it was the last time the Arctic Ocean was ice free, while it is true the continents are in different configuration now forcing currents to flow somewhat differently 400 ppm isn't even a bump in the road for humanity, we are on track to hit 410 ppm by 2020 and possibly 450 by 2050, that would put us in the ice free regime in the northern hemisphere almost certainly based on newer modeling coming out. If that all turns out to be accurate based on paleo climate records as it is and the model studies I linked to in my earlier post are true then we could be teetering on the edge of the tipping point and most of us have no idea the edge is even this side of the horizon. It is that thought that keeps me paying attention.
Toggle Commented Jul 26, 2013 on Second storm at Arctic Sea Ice
I have been reading reports lately that indicate a complete absence of Arctic sea ice in early summer could be the trigger to flip the northern hemisphere into the hothouse mode just as it was when last the Earth had 400 ppm CO2 in the atmosphere. Several researchers have been modeling the effect of an ice free Arctic ocean and the majority of runs show that the Ferrel cell of atmospheric circulation would grow from its current Equator to 30 north range and encompass the entire northern hemisphere. See http://www.fields.utoronto.ca/programs/scientific/10-11/biomathstat/Langford_W.pdf and http://www.seas.harvard.edu/climate/eli/research/equable/hadley.html The studies don't say how long the Arctic has to be ice free, it could take a decade or more for the transition to happen once we are there, but at the rate we are going now I don't think it is nearly as far off in the future as we have been lead to believe by the IPCC.
Toggle Commented Jul 26, 2013 on Second storm at Arctic Sea Ice