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Pete Williamson
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Magma says "This is starting to look like yet another example of bistable behavior with tipping points" The curious thing is why with all these tipping points it seems the earth was perched on the edge waiting for humanity to push it over. Why shouldn't the tipping point be now or in 20oC time?
Toggle Commented Mar 21, 2014 on PIOMAS March 2014 at Arctic Sea Ice
Interesting the discussion drifted to PIOMASS. If ice bridges can be characterized as dynamical processes, with no clear relation to thermodynamics. And if they contribute to overall ice volume by regulating ice loss through the Nares strait, I think I've read maybe 10% of the exported ice leaves via Nares. And if there formation can be quite variable, I've read the date of their formation and collapse can vary. Then I'm wondering if anybody knows if PIOMAS can take account of these types of dynamical changes in calculating ice volume. Maybe the final impact is quite small and these sorts of variations are contained in the error bars?
Toggle Commented Feb 2, 2014 on 2014 Nares Strait ice bridges at Arctic Sea Ice
Wili said "So should we be using these CryoSat numbers or the lower PIOMAS numbers ........ (Of course, both show dramatic ice loss over the decades.)" Sorry the pedant in me couldn't let this slide by. It's not possible for a satellite that's been generating data for 4 years to tell us anything over the decades. Just 4 years! My wider point can be summed up by something a lecturer at university once said, from a google search it appears to originate from the geneticist William Bateson. Bateson's advice was to "treasure your exceptions". My understanding of that is to take note of observations that confound your expectations, it's data like this that has the potential to give greater insight into what is occurring more generally in the arctic. Yet most commentary seems to want to do little more than label this data point as weather and then move on. Also I see ESA's point that the MYI has undergone a recovery but their data suggests to me that the 'recovery' is much more extensive than that (Barentz being the exception). The map for 2013 shows cyan/green extending much further into the Arctic than previous years and for that phenomenon to be homogenous over all the regions were ice is present. Shorthand, the ice is thicker everywhere (almost)! And finally a question. Why do we have to call this weather? The great clearout of MYI in 2007 was weather. Why can't we say all the post-2007 data is weather given the large impact that year and subsequent storms etc have had. It seems rather one sided to invoke weather for the years when ice loss is less.
Good to have US data back. Sans Barentz, it looks like the European side of the Arctic is going through something of a recovery. It'll be interesting to see if it can spread into Barentz Sea as well
AFU I don't see why on this issue you should think that JC is at odds with your thinking. The mainstream seems to, at least in part, invoke 'internal variability' to explain the pause, all the Wyatt paper seems to be doing is trying to put flesh on the bones of that idea. The stadium wave may not turn out to be the explanation but something has to. The present situation where variability is seen as little more than the residual in an analysis has to be put behind us. The pause is going to be the impetous for others to get involved ( actual others are already there)
Except that it does appear as though the Atlantic waters moving north to the Arctic peaked in temperature around 2007. A "recovery' in the ice extent in the Barentz/Kara would make sense, everything else being equal.
So the possibility of another crystal-ball gazing game in the arctic. This graph shows that the winter maximum of the CT ice area hasn't broken 14 million for 10 seasons Given the spooky melt season this year what are the chances that that particular upper limit might be breached.
Toggle Commented Sep 21, 2013 on Pinpointing the minimum at Arctic Sea Ice
Beaufort Sea continues to look interesting. Just from eyeballing the CT area chart it looks like this year wouldn't be out of place in the late-1980's and late-1990s. It looks like for each year since 2007 the Beaufort Sea has been in negative anomaly territory for more than half the year. This year it's looking like it's going to be negative for little more than 2 months. Given the endless observations of cracked and rotten ice in the region it seems rather remarkable.
Toggle Commented Sep 19, 2013 on Pinpointing the minimum at Arctic Sea Ice
Just meant to add the survival of alot of the Beaufort Sea ice make contribute to that. Cheers
Neven, I think at some point you're going to have to stop being surprised at the lack of melt (or the persistence of extent) this year :P It looks like this might be a 'new high' post the 2007 MYI clear out. It may be better understood as part of the natural variability and if we want to understand what's going on then we should be looking at the average extent since 2007 rather than expecting records to be broken. There is probably too much focus on record-breaking in the arctic. Given that ice can persist (or fail to persist) for 5 years or more suggests we should be trying to understand processes on that timescale as well. Not only has a lot of FYI survived but so has much of the SYI (2nd) which is going to start showing up in the MYI category next year. It possible that at least a bit of a 'recovery' in the MYI is on the cards.
alert wili knows about the 'experiment'. Initiate alpha one zero! Now, do it now!
Toggle Commented Aug 19, 2013 on ASI 2013 update 7: cold and cloudy at Arctic Sea Ice
Blaine the papers hint at were Serreze is coming from. "The most obvious feature is strong variability." "Arctic cyclone activity displays significant low-frequency variability" If you understand what those sentences mean and then try to put the past two summer season into that context then you can see why it might be easy to be misled over the direction of the trend. It seems like a lot of climate science is like this, crudely put we need lots of data in order to pull any signal from the noise. Just from the papers you link to it would seem safest to say there is no clear trend. We would have to see the detail behind his claim of a drop in cyclone activity to judge it in the context of others work. All that said I would love to see an arctic cyclone activity data set that continued through to present day, the recent years of low ice extent would give more insight. I actually emailed John Walsh (bad me for scientist bothering) to see if he had extend his CAI beyond the 2002 year in the publication, unfortunately not! I really don't get why people are reacting so badly to what Serreze has said here.
A strange day today On the ASIB there seems to be something of a celebration because the public believe arctic climate change affects their weather when the scientists are clearly still debating this, and when L Hamilton says that belief is in part shaped by what the weather was like when they were interviewed. A (lack of) logic that would normally have consensus-believers frothing. And over at WUWT they are celebrating the outputs from climate models, because they show something other than CO2 might be causing the changes in the arctic. Where is the consistency?
Toggle Commented Aug 14, 2013 on Perception of the Arctic 2 at Arctic Sea Ice
Congratulations, it must be hard to be in the same room as your ego ATM! Just to massage it more, I was totally unaware you had no background in climate science. You write with a clarity that belies that. I think I prefer citizen scientist over armchair, the later suggest a passivity that seems to be non-existent in all the individuals that are doing this sort of work.I have a friend who is recovering from a brain tumour who, when she has the energy, goes out to the local wetlands and counts dragonflies.There are probably issues on which we disagree when it comes to environmentalism, but I can't critise the fact she's out there adding to our understanding of ecology.
Sorry if anybody has already made this point. Most seem to have focused on the potential thinness of the ice to allow the storm to churn up the ice, but there is also a flip side. Given that much of the ice is FYI and flat it might actually be that these storms are affecting the present day ice less than it might have affected ice from decades past when more ridged MYI was around and acting as a nice sail for the winds to press against.
Toggle Commented Aug 10, 2013 on Third storm at Arctic Sea Ice
Question. What are the temperatures like while these storms are turning?
Toggle Commented Aug 8, 2013 on Third storm at Arctic Sea Ice
Eli Rabett "Anyone remember the coasts of Greenland being so ice free?" It's possible the person who drew this DMI ice chart for August 1936 might remember. If he's still alive! From this archive
Toggle Commented Aug 8, 2013 on Third storm at Arctic Sea Ice
This paper might answer some of your cyclone frequency needs, unfortunately it only goes to 2002. Greedy old me wants an update to more recent years. here's the paper It uses "cyclone activity index" CAI ("integrates information on cyclone intensity, frequency, and duration into a comprehensive index of cyclone activity")rather than just counting individual storms. Fig 5 shows an increasing trend in CAI but also a large amount of inter-annual variability. So arctic storms are getting more common and/or longer and/or more intense but this trend is accompanied by a lot of year-to-year noise. My own slightly more simplistic view was going to suggest that if storms are caused by specific features (largescale atmospheric patterns, patterns of open water/ice coverage, snow cover etc.) then if these feature persist through a season then it would seem likely that years that breed many storms might be a possibility. Tropical cyclone seem to follow this sort of pattern of inter-annual variability.
Toggle Commented Aug 8, 2013 on Third storm at Arctic Sea Ice
Blaine just to correct some points you made. "The result was massive melting and massive amounts of melt ponds." Melt pond coverage was 20-50% and this is normal for the position of the webcams. "These quickly froze over again " This is not true the melt ponds were sitting above sa level and drained into the ocean. It's all outlined in the link below The media reports of lakes at the North Pole was somewhat sensational. But I agree with the rest of your point the ever changing nature of the sea ice must make remote sensing a challenging endeavor.
Lord Soth it looks like your right. Before the melt pond 2 black sections were poking out of the ice on the measuring stick in the foreground. Afterwards it's 4 black sections. The website says each black and white section is 10cms, so in the course of 2 weeks about 40cms of ice melted and then drained away.
It seems like it's mainly the pacific side of the arctic that is giving the strange results. From this paper I came across this quote "Pacific waters carry significant amounts of heat into the Arctic—although highly variable from year to year, the heat flux (relative to the freezing temperature of seawater) is enough to melt 1–2 million km2 of 1 m thick ice (Woodgate et al., 2010). Certainly, the pathways of Pacific Water into the Arctic are clearly reflected in the structure of the sea ice edge, implying that Pacific Water heat acts as a trigger for the onset of western Arctic sea ice melt, especially in 2007 when the Bering Strait oceanic heat flux was over twice that in 2001." Beyond the weather there is the possibility that an underlying process, like the variable heat flux from the pacific ocean, is at the heart of this (I mean generally the perceived resilience of the sea ice this year). Unfortunately I don't see any data beyond 2010/2011 to back-up this speculation though.
"This melting season is completely draining me, making me feel like I don't know anything." I've spent most of the 20+ years of my medical research career feeling exactly the same way. It's called science. I think it's because you spend most of your time with your nose in what you don't know and take for granted what you do.
Sorry OT but any ideas what might be causing the .... dare i say pause ...... in the melt in the cryosphere today sea ice area?
Toggle Commented Aug 4, 2013 on PIOMAS August 2013 at Arctic Sea Ice
I don't get what the guy in the hat in the video is trying to say here, there seems to be some wonky logic. "Starting to slip" suggests it wasn't slipping before, backed up by "did nothing before" and "frozen at the base". Then he's talking about "acceleration of 2-3%". Can you measure an acceleration from 0 to something in terms of %? I actually thought that pretty much the whole of the ice sheet is on the move. Starting to slip???? Surely it's (almost) always slipping????
So I think it's worth just stepping out of the arctic for a second, this is going to be grossly general. The engine for ice melt is avection (??) of heat into the arctic from NH mid-latitude. The following is HADCRUT4 NH (40N-75N) but pretty much any slice of the sub-polar NH looks similar. So it looks like the engine has stalled, the polynomial may be meaningless, but for now the warming that occurred up to the mid 2000's has stopped. Now there are internal processes in the arctic that may or may not have come to equilibrium and there are many interesting weather phenomenon and so on that Neven continues to educate us about. But there is an argument that all other things being equal there's reason to think that Arctic ice isn't going to change much until the engine get's going again. Maybe it's time to stop being surprised when the Beaufort Sea doesn't crash.