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John Christensen
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Somewhat off topic, but wanted to share that large oil companies continue following the money, not the science:
Toggle Commented 2 days ago on PIOMAS May 2016 at Arctic Sea Ice
Example: January '16 had AO of -1,45, while January 2013 'only' had AO of -0,61, which in principle should have resulted in more volume growth in '16 than '13. The negative AO index of 2013 seems to have had more impact than the AO of Jan. 2016, because preconditioning had taken place for the 2012/13 freeze, which clearly was not the case this past winter.
Hi D, Yes, I have looked at AO for other months also and while they will certainly have an impact (Especially clear skies in July or January), then the correlation with volume changes seems somewhat stronger for the months 'preconditioning' the melt or freeze period.
Hi Chris, In your analysis, have you looked at the AO index and how this factor could provide additional explanatory information when combined with temperature? It seems reasonable to assume that: - Fall season(Oct-Dec): Clear skies leads to additional heat loss from NH continents and open water (AO-), therefore improving conditions for Arctic sea ice growth. - Spring season (Apr-Jun): The reverse; clear skies (AO-) allow more sun radiation to reach the NH, melting snow faster, heating up open sea water, and creating melt ponds early. Averaging the AO index for spring seasons since 2005 and sorted from negative to positive AO (For 2016, added '0' for May and June): Year Av. Spring AO 2008 -0,58 2010 -0,40 2005 -0,40 2016 -0,37 2012 -0,18 2009 0,27 2007 0,29 2014 0,31 2006 0,46 2013 0,46 2011 0,46 2015 0,80 Strong melt seasons are clearly towards the top of the list and reduced melt seasons towards the bottom - with 2007 as a noted exception. AO index for fall seasons (Oct-Dec) show a similar pattern: Year Av. Fall AO 2011 1,49 2013 1,26 2015 1,05 2008 0,81 2006 0,59 2007 0,23 2014 -0,42 2005 -0,62 2012 -1,12 2010 -1,16 2009 -1,50 As can be seen above, fall seasons of 2011, 2013, and 2015 were cloudy, leading to overall reduced NH heat loss. If you then combine the AO index of the preceding fall season and the spring season AO index, then you may be able to spot a record melt season coming up: Year Total AO influence 2012 1,67 2016 1,42 2014 0,95 2008 0,81 2009 0,53 2007 0,30 2006 -1,07 2010 -1,10 2015 -1,22 2013 -1,58 2011 -1,62 What is interesting for the 2012 season with incredible volume loss compared to the prior year is that the AO numbers leading to this 1st ranking were from October 2011 to June 2012.. And even with neutral AO for May and June 2016, this season is already in a comfortable 2nd place by a large margin, indicating a very considerable volume loss from a year ago. At the other end of the list it was also by the end of June 2013 possible to identify this year as having strong volume growth compared to 12 months prior.
Note to self: Seek and you shall find: "However, the salt content of oceans lowers the freezing point by about 2 °C (see here for explanation) and lowers the temperature of the density maximum of water to the freezing point. This is why, in ocean water, the downward convection of colder water is not blocked by an expansion of water as it becomes colder near the freezing point. The oceans' cold water near the freezing point continues to sink." Let me go get another cup of coffee..
Sorry, got that first line wrong, please disregard.. ;-)
Thanks Lodger; and the density gradient really is a function of salinity and temperature. The lines in the diagram seem a bit simplified, since water has its highest density at 4C, but again this difference is so small that the level of salinity largely determines the pycnocline or buoyancy of the body of water: Temperature(oC), Density(kg/m3) 0 , 999.8 4 , 1000 10 , 999.7 20 , 998.2
idunno, You should read this paper from 2011 (By: Kirstin Werner, Robert F. Spielhagen, Dorothea Bauch, H. Christian Hass, Evgeniya Kandiano, and Katarzyna Zamelczyk) for findings on variability of Atlantic Water inflow via Fram: Atlantic Water advection to the eastern Fram Strait — Multiproxy evidence for late Holocene variability
Reference from Lodger: "A "fresher" layer will freeze as it cools, a saltier layer will sink forcing warmer water to the surface." What is described here regarding the "saltier layer" seems to be the halocline of the Pacific and the Atlantic, where warmer waters enter the Arctic Ocean (AO). The salty warmer water sinks as it moves northward and slides below the polar mixed layer due to both the higher salinity level as well as slightly higher density of water at 3-5C compared to polar surface waters of low salinity and temperature near 0C. Of the two factors, the difference in salinity level (E.g. typically believed to be more important than the temperature difference and The low salinity level of the polar mixed layer is primarily kept in place by the river outflows into the AO from surrounding continents. As the saltier water cools, it is placed between the colder surface waters and the Arctic deep water, which is also colder, so there is not overturning taking place, allowing for the cooling of the salty warm water to cause other salty warm water to reach the surface. Therefore, while the next sentence would apply to a typical open ocean scenario, it does not seem to apply to the AO: "If the warm layer is a thousand meter thick, it's not going to freeze in a single Winter." So, I think the Russians are right; without significantly reducing the freshwater flow to the AO, it will be very difficult to break the salinity-based stratification of the AO water column, or at least that breaking this stratification would take considerably longer than for the Arctic to become ice-free for a part of the year. Am I missing something here?
I really should not be contributing here, but just wanted to put your hypothesis to test wayne: When going back in the charts of DMI 80N temps, it seems like the years with well-consolidated ice surface could easily have the surface temp above 0 a few days before the average day this should occur. Why? Possibly, because the top of the ice has melt ponds and so is about 0, allowing the air to be slightly warmer, while shielding the surface from below 0 temp water. When the ice surface has many fractures, then the colder top layer water could cool down the surface temperature for perhaps 4-10, depending on weather. In this fashion, an early rise to 0 could mean a relatively consolidated ice surface, while a very late date for reaching 0 (2013 being the best example I see) shows how the water in the highly fractured pack keeps the surface temp down - evidently greatly assisted by the cyclones of that year..
Toggle Commented May 14, 2016 on PIOMAS May 2016 at Arctic Sea Ice
And interestingly, Dr. Maslowski mentioned in the interview of Dec. 2007 that his original prediction is from the AGU Fall Meeting 4-5 years earlier, meaning that his prediction originally was from 2002 or 2003.
Kevin said: John Christensen: You have made the same mistake that many others have made. Neither Maslowski's original AGU presentation nor the radio interview you pointed to support your claim that he originally said 2013 and then modified it. OK, then check this compilation on Dr Maslowski projections: May 2006: American Meteorological Society seminar, appears not to be from a presentation, but has been quoted by Joe Romm: “If this trend persists for another 10 years-and it has through 2005-we could be ice free in the summer.” October 2007: “Experts say the ice retreat is likely to be even bigger next summer because this winter’s freeze is starting from such a huge ice deficit. At least one researcher, Wieslaw Maslowski of the Naval Postgraduate School in Monterey, Calif., projects a blue Arctic Ocean in summers by 2013.” December 2007: Australian ABC: “A US-based team has told a conference in California that the northern polar waters could be ice-free in summer by 2013. Professor Wieslaw Maslowski from the Naval Postgraduate School in Monterey, California, has been presenting his work to a meeting of the American Geophysical Union.” December 2007: Beyond Zero Emissions, Dr Wieslaw Maslowski predicted a 2013 Ice Free Summer Arctic five years ago - now he says that may have been too conservative, Radio Interview, Australia: “We speak to Wieslaw Maslowski about his prediction that by the summer of 2013, we will have completely lost ice cover in the Arctic. Dr. Maslowski says that the complete loss of summer ice may actually happen sooner.” HOST: As reported in the NY Times that you said that 2013 was a possibility and perhaps you had actually projected this some years ago, that we could lose the summer sea ice extent, that is in the summer solstice, correct? MASLOWSKI: That is correct. So the minimum in the Arctic sea ice extent has been typically occurring sometime in September, between early September and late September every summer, so the minimum of ice extent has been defined as the ice edge of say 15-20% ice cover and then everything inside this ice-edge position is considered to be the ice extent. .. And our studies are suggesting that actually the volume and the thickness is decreasing even faster than the areal observations from satellites. And this way we are saying that actually if we already have lost probably 40% of the volume in the Arctic so far, if we project this trend ongoing from the last 10-15 years, we probably will hit zero sometime in the summer mid-next century, mid-next decade, I’m sorry. HOST: Sorry, there has been other projections from some glaciologists from around the 2020, so somewhere around the range, you said 2013 in NY Times, where it was reported? MASLOWSKI: That is correct. .. My statement on the, that you quoted on the, that was printed in NY Times of 2013, my first prediction where I actually had this projection stated explicitly was about 4-5 years ago in San Francisco in the AGU Fall Meeting, so I am actually not upgrading my projection – I’m just saying it might happen sooner, but we were one of the early people, who were saying it might happen within the next decade instead of the end of this century.“ October 2009: “Toward Advanced Understanding and Prediction of Arctic Climate Change” 34th Annual Climate Diagnostics and Prediction Workshop, Monterey, CA, 26-30 October, 2009 On slide 11 Dr Maslowski is reviewing trends on Arctic ice volume decline observed and notes: “If this trend persists the Arctic Ocean will become ice-free by ~2013!” March 2010: State of the Arctic Meeting: On slide 12 Dr Maslowski is reviewing trends on Arctic sea ice volume and notes: “Combined (95-07) model / data linear volume trend of -1075 km3/yrprojects ice-free fall by 2016 (3yrs uncertainty -95-07)” April 2011: New warning on Arctic sea ice melt, BBC, 8 April 2011 “Scientists who predicted a few years ago that Arctic summers could be ice-free by 2013 now say summer sea ice will probably be gone in this decade. The original prediction, made in 2007, gained Wieslaw Maslowski's team a deal of criticism from some of their peers. Now they are working with a new computer model - compiled partly in response to those criticisms - that produces a "best guess" date of 2016. Their work was unveiled at the European Geosciences Union (EGU) annual meeting. "In the past... we were just extrapolating into the future assuming that trends might persist as we've seen in recent times," said Dr Maslowski, "Now we're trying to be more systematic, and we've developed a regional Arctic climate model that's very similar to the global climate models participating in Intergovernmental Panel on Climate Change (IPCC) assessments," he told BBC News. And one of the projections it comes out with is that the summer melt could lead to ice-free Arctic seas by 2016 - "plus or minus three years". .. Inclusion of this data into the team's modelling was one of the factors causing them to retrench on the 2013 date, which raised eyebrows - and subsequently some criticism - when it emerged at a US science meeting four years ago. What you see from this thread, Kevin, is that Dr. Maslowski has refined his predictions along with the progress of his work and models, which all seems quite reasonable.
Kevin said: Dr. Wieslaw Maslowski of the Oceanography Department at the Naval Postgraduate School was the first scientist that I know of who predicted an ice-free arctic in the very near future. In 2006, before the 2007 wake-up call, he said the arctic could be ice free in 10 years. His prediction was 2016 +/- 3 years. This is 2016 and I think there's a better than 50% chance his prediction will come true this year. And if not this year it will definitely happen within 5 years. The 2006/07 prediction by Dr. Maslowski was actually for an ice-free Arctic in terms of extent by 2013 (with the qualifications), as you can hear in this Dec. 2007 podcast by Dr. Maslowski himself: In the same podcast he mentions that the ice volume is decreasing faster than the extent or area, and that the Arctic ice volume would 'probably hit zero by mid-next decade'. In 2011, the Arctic ice extent prediction was modified to 2016 +/- three years:
Hi Neven, I stand by my comment: Dr Andrew Slater is with the NSIDC and has the NSIDC logo on this web page, with no disclaimer that this is unrelated to the NSIDC. The issue of course with the graph not fitting the scale is that it alters the discourse to be around 'off the scale' data, and other blogs and news outlets can pick this up. With his background, Dr Andrew Slater cannot be ignorant of this, which is the intentional piece: I don't see that he rigged the scale, but he decided not to fix the scale, before making the graph available. But I respect this type of comment shouldn't be on your blog, so will go into hiatus, as we enter what may become the worst Arctic sea ice melting season so far. - Never complained about PIOMAS though.. ;-)
Toggle Commented Apr 4, 2016 on Winter analysis addendum at Arctic Sea Ice
Impressive data on the FDD from the NSIDC, thanks Neven! - And what any 1st year student would have learned about manipulative statistical representation: The NSIDC couldn't resist the visual trick of letting the 2015/16 line exit the scale, rather than make the scale fit the lines.. ;-)
Toggle Commented Apr 2, 2016 on Winter analysis addendum at Arctic Sea Ice
Thank you for the link Neven! wayne, I will certainly check out your theory and also it's very enlightening to see more about your background. The NOAA AO index is still positive, but is clearly trending towards moderate negative, so will be very interesting to follow the development.
Toggle Commented Apr 2, 2016 on 2015/2016 Winter analysis at Arctic Sea Ice
A true work of art, thank you Neven! Comparing to the longterm AO index for winter months (See below), it is clear that the four seasons with very positive AO (2006/07, 2011/12, 2013/14, and 2015/16) are outliers and that we have seen reduced sea ice area and extent increases during those winters. Hi wayne, It will be interesting, if we will indeed have a La Nina event this year, but I have not seen any papers linking La Nina to negative AO/clear Arctic skies, so please share if you have references or your own data to support that. Looking at the longer-term AO trends for winter months, it seems like we have a multi-decadal trend, as seen from the averages of NOAA AO data: Period Winter (Nov-Feb) Average (1950-2015) -0,28 Average (1950-1959) -0,50 Average (1956-1965) -0,75 Average (1966-1975) -0,40 Average (1976-1985) -0,54 Average (1986-1995) 0,42 Average (1996-2005) -0,24 Average (2006-2015) -0,05 From the numbers above: 1) Long-term average AO (1950-2015) is negative for the winter season (Nov-Feb), indicating overall tendency for clear skies. 2) Negative AO was most pronounced in the period of 1950-85. 3) 1986-95 indicated a decadal-long shift to positive AO during the main winter months, which generally must have reduced ocean heat loss and therefore limited sea ice growth 4) 1996-2005 saw overall negative AO again, but since 2006 we have seen a jigsaw/non-decided trend for AO during winter months. These longterm shifts are also visible from the NOAA graphic, although it is looking at Jan, Feb, March:
Toggle Commented Apr 1, 2016 on 2015/2016 Winter analysis at Arctic Sea Ice
Neven, Your first AO graph is actually great, as it shows the winters of 2006/07 and 2011/12 starting with very positive AO, and this past winter being as bad as those two for the first months of winter. - Which certainly does not bode well for the coming melt season (If you like the ice to stay that is) It seems to be less important how the AO is behaving in Jan and Feb compared to Nov and Dec. If you had included the cold winter of 2012/13, it would have provided a nice contrast to those other years.
Toggle Commented Mar 31, 2016 on 2015/2016 Winter analysis at Arctic Sea Ice
Hi Neven, Thank you very much for sharing this. I was trying to consolidate your numbers with the monthly values from my data from NOAA, which seem to be slightly different: Winter Nov Dec Jan Feb 2006/07 0,521 2,282 2,034 -1,307 2007/08 -0,519 0,821 0,819 0,938 2008/09 0,092 0,648 0,8 -0,672 2009/10 0,459 -3,413 -2,587 -4,266 2010/11 -0,376 -2,631 -1,683 1,575 2011/12 1,459 2,221 -0,22 -0,036 2012/13 -0,111 -1,749 -0,61 -1,007 2013/14 2,029 1,475 -0,969 0,044 2014/15 -0,53 0,413 1,092 1,043 2015/16 1,95 1,444 -1,445 -0,023 What is noticeable from these numbers: 1) The winter of 2006/07 saw positive AO in Nov, Dec, and Jan, which seems to work a bit like melt ponds in the early spring: If the ocean does not loose heat in early winter months, ice extent tends to stay very low. And this winter had exceptionally low ice extent. 3) The 2009/10 winter had great (AO) conditions for ice growth after a slow start 4) The winter of 2011/12 also saw positive AO in early winter months, setting the stage for the summer of 2012. 5) The winter of 2012/13 on the contrary saw lots of clear skies and significant ice growth causing lots of 'recovery' discussion at the time. 6) The three latest winter seasons were not great from a weather perspective with positive AO in early months for two of them and just slightly negative AO for the start of the 2014/15 winter. It is clear - and Wikipedia IMO has the best guide to the AO - that this is not the sole factor, but one of the components influencing the environment in which sea ice is created during the Arctic winter.
Toggle Commented Mar 31, 2016 on 2015/2016 Winter analysis at Arctic Sea Ice
Darn, you were right, thanks AIG! What it should have been: - November and December were dominated by positive AO index, which brings more cloudiness and low pressures to the Arctic region, causing reduced ocean heat loss, higher temperatures, and moves the jet stream further north with many storms entering the Arctic seas.
Toggle Commented Mar 31, 2016 on 2015/2016 Winter analysis at Arctic Sea Ice
Hi AIG, No, I was not trying to confuse you, so please let me know what leads to that state of mind. The AO index:
Toggle Commented Mar 31, 2016 on 2015/2016 Winter analysis at Arctic Sea Ice
Thank you for a great Arctic winter analysis Neven! The only item I was missing was a review of the atmospheric conditions, which certainly seem to have been a factor for the Arctic sea ice this winter: - November and December were dominated by negative AO index, which brings more cloudiness and low pressures to the Arctic region, causing reduced ocean heat loss, higher temperatures, and moves the jet stream further north with many storms entering the Arctic seas. (In contrast, Oct, Nov, and Dec 2012 all had negative AO index, which caused predominantly clear skies, more heat loss and increased sea ice build-up).
Toggle Commented Mar 31, 2016 on 2015/2016 Winter analysis at Arctic Sea Ice
Hi Bill, Yes, the photo is certainly a fake - not just because of the colors - but also because: - The helmets have no horns - There should be barrels of akvavit (Older name for snaps) visible on the boat, as Vikings (Still to this day) going south of equator always bring barrels of akvavit with them. If they cannot drink it all during the journey, they sell the leftovers as 'linie akvavit' in Norway:
Toggle Commented Mar 30, 2016 on Mad Max 2: The Arctic Warrior at Arctic Sea Ice
I feel my fact-oriented eyes are being opened for the first time, seeing that there is no black or white, and that the black knight could be mocking the other knights for the sheer fun of it. I will leave Dr. Inferno to his business, which I am sure will have no relevance to my future endeavors..
Toggle Commented Mar 27, 2016 on Mad Max 2: The Arctic Warrior at Arctic Sea Ice
OK, OK, Kevin and Neven, but could you then please explain what makes sense in the entry that idunno provided a link for: "This appears very much to be a menu button. Let me explain to you how these work. A menu button is a piece of technology designed to always display a menu when they are clicked on. But if you click on the University of Illinois menu button in the above image no menu appears. Go on, try moving your mouse over it and clicking, it does nothing except making the image larger. Software engineers are not like climate scientists, they have to make sure the computer programs they write work all the time, every time, and so they learn to never make mistakes. So I have to assume that someone at the University of Illinois has deliberately sabotaged the menu button. I wonder why. What could be on the hidden menu? Perhaps the menu contains links to scientist's emails which They don't want made public. Perhaps there is an option to display the real undoctored sea ice data that are being hidden from us. Or perhaps the button is just another one of Lewandowsky's little traps to try and falsely paint us as conspiracy theorists. Yes I can well imagine Stephan Lewandowsky meeting with suited UN figures at the Paris COP21 in a closed meeting room, discussing a demented form of button over taxpayer funded mugs of hot coffee. A button that can be deployed onto websites that will capture not only the imagination of climate skeptics, but also their IP addresses which are subsequently loaded into a database named agenda21. Someone more proficient at being unethical than me should probably try to hack that button and find out what is behind it. If not I sense an FOIA request in the making. *These are actual files I keep in my house, in a large binder. Update: A commenter, now banned, has kindly pointed out that a button in a copied image from a website isn't necessarily going to work when copied onto a blog. While this may potentially explain why the menu button doesn't work, I stand by my comments and the general thrust of my argument remains. I would think the University of Illinois should really put a disclaimer on their website pointing out that buttons will not work when an image is taken. This kind of lack of attention to detail is becoming a hallmark of climate science."
Toggle Commented Mar 27, 2016 on Mad Max 2: The Arctic Warrior at Arctic Sea Ice