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Anu
<-- 3 year old daughter - younger than Dr. Hansen's grandchildren of "Storms of My Grandchildren" and the main reason I'm interested in Global Warming
The oldest known civilization is Sumerian - the oldest, largest city is Uruk (starting from 4000 BC), with a massive ziggurat built for the sky-god Anu. Climate was important to early farmers, but without Science, they could only pray to Anu and hope the Euphrates River allowed them to prosper. The Anu worshippers *did* invent writing (cuneiform on clay tablets), so that helped with eventually replacing primitive entreaties to the gods with a deeper, scientific understanding of the world. For some people.
Interests: climate change, pre/early/history, peak oil, electric cars, foreign policy, astrophysics
Recent Activity
Artful Dodger - I've been away for a couple years - has Neven's productive little blog been discovered by argumentative mouthbreathers? I suppose it was bound to happen. But it's hard to tell a curious teenager from a Christopher Walter Monckton, 3rd Viscount Monckton of Brenchley...
Toggle Commented May 27, 2013 on ASI 2013 update 1: a slow start at Arctic Sea Ice
I hope Dr. Maslowski figures out the Regional Arctic System Model (RASM) before the summer Arctic Sea Ice is gone this decade - here's a short article from Feb 2013: http://www.oc.nps.edu/NAME/ResearchMedia.EU_Maslowski_highres.pdf Could you offer some thoughts on the potential reasons behind the record sea ice melt of 2012? In my opinion, increasing heat content in the subsurface western Arctic Ocean, together with the snow-ice/albedo effect, advection of warm summer Pacific and Atlantic water, and stronger air-sea coupling due to thinner or no sea ice is one of the main reasons why the summer sea ice cover has been declining in the Arctic. This extra energy and its storage in the upper ocean can help explain the longterm negative sea ice trend and especially its acceleration since the late 1990s. The entrainment of this heat into the surface mixed layer (where it can affect the growth or melt of sea ice or be released to the atmosphere) is controlled by small scale processes, such as eddies, upwelling, coastal currents, mixed layer depth and vertical stratification. For a long time, Dr. Maslowski has argued that these hi-resolution, small-scale processes that GCM's miss because of their large grid sizes, are the reason they predicted the disappearance of summer Arctic sea ice towards the end of the 21st century. Regional, hi-res models can capture important small scale processes, and lead to better predictions. 2016 ± 3 years.
Toggle Commented May 27, 2013 on ASI 2013 update 1: a slow start at Arctic Sea Ice
We know that the Planet Earth, was once much warmer than it is today, in previous Geological Epochs. More recently, the 'Little Ice Age' had only ended about 1850 (Maunder Minimum). It is also important to recognize where we are on the 'Sunspot Cycle' (Milankovitch cycles). Can we adapt to the changing conditions, on a very overpopulated planet? Posted by: Spacezorro1 | May 27, 2013 at 06:33 The Maunder Minimum ended about 1715 - there was another, less severe minimum of sunspots, the Dalton Minimum, that coincided with the end of the "Little Ice Age", about 1830 - with the "LIA" ending about 1850. Milankovitch cycles refer to the interplay of eccentricity, axial tilt, and precession of the Earth as it orbits the Sun - this leads to orbital forcings which are fairly easy to calculate. As far as I know, these are independent of short term Sun variations in sunspots, etc. - I don't think they can predict, or even explain, all those slight irradiance variations of our G2V star. Can we adapt to the changing conditions, on a very overpopulated planet? Certainly small tribes of humans are very resilient - a few million humans could survive another Ice Age, or 9° F average global warming. But Global Civilization ? Which evolved during a very stable Holocene climate, built on top of global agriculture that expects a fairly stable climate? I don't think so. Changing hydrology will be the downfall - droughts and floods. Disappearance of glacier fed rivers in Asia. Agriculture will crash, billions will starve, wars will break out, and nuclear wars will be brutal. 90% fatalities brutal. Can small tribes of humans survive on a hot, radioactive planet ? Maybe. What about the methane hydrates? Depends on the inertia of CO2 in the pipeline before the Wars. Things could go from Ugly, to Very Ugly. Cheers.
Toggle Commented May 27, 2013 on ASI 2013 update 1: a slow start at Arctic Sea Ice
Two quotes come to mind... The first is from the TV series Firefly when Book replies to Mal: "We're very close to true stupidity here." Posted by: Sam | May 21, 2013 at 01:40 The Shepherd would be disappointed in Humanity's progress to date. I'm hoping that this potential climate catastrophe doesn't spiral out of control this century, leading to people one day echoing this classic movie quote: http://www.youtube.com/watch?v=dsx2vdn7gpY
Toggle Commented May 22, 2013 on The Four Charts That Really Matter at Arctic Sea Ice
I'm a fan of all four of your graphs - well chosen. Especially the 2000m ocean data, rather than 700m. The 2012 September NSIDC graph is here: http://nsidc.org/arcticseaicenews/files/2000/09/Figure3.png Sorry if someone else above has pointed this out, didn't have time to read all the comments... That last data point is dramatic.
Toggle Commented May 22, 2013 on The Four Charts That Really Matter at Arctic Sea Ice
IARC-JAXA ticked UP (corrected final values) for the first time this summer: 9/6/12 - 3676406 km^2 (prelim 3614219) 9/7/12 - 3664531 km^2 (prelim 3601875) 9/8/12 - 3674844 km^2 (prelim 3595781) 9/9/12 - preliminary 3593750 km^2 It might not be the minimum for the summer, but it definitely shows the end is near. 2007 had a local minimum, went up a bit, then down for the final minimum a few days later. Today's preliminary value is very slightly lower than yesterdays - 2,031 km^2 smaller.
Toggle Commented Sep 9, 2012 on Minimum open thread at Arctic Sea Ice
@Seke Rob | September 05, 2012 at 15:54 Roy Spencer and his colleague John Christy, two deeply religious Christian believers from the Bible Belt of the USA (Spencer believes in Intelligent Design, Christy was a Baptist Missionary and has a Master of Divinity degree from a Seminary), have been trying to "prove" the climate is just fine for about 30 years. Not only did Spencer screw up the satellite temperature measurements of the troposphere for decades (which had to be fixed by outside scientists, finally), but he used his errors as the basis of lucrative speaking-tours and book deals to preach to the climate change deniers. http://thinkprogress.org/romm/2008/05/22/202659/should-you-believe-anything-john-christy-or-roy-spencer-say/ Roy is convinced that his good buddy, Jesus Christ, would never allow something really bad - like ruining the Holocene climate in which Civilization developed - to happen to him. Therefore, there must be Good News in the data somewhere - perhaps the clouds will save us (he actually wrote a book arguing this)... http://cloud.frontpagemag.com/wp-content/uploads/2010/01/Dr.-Roy-Spencer.jpg Note that John Christy is the guy referenced in Neven's article: http://neven1.typepad.com/blog/2012/08/similar-melts-from-1938-43.html People like Spencer and Christy will never look at things objectively, because their "feel good" religion requires them to believe it can't possibly be as bad as it is.
Posted by: BlackDragon | August 28, 2012 at 06:04 I believe the navy researcher (can't remember his name) who has been the most consistently correct about predicting the earlier than expected melt... I believe you're thinking about Dr. Wieslaw Maslowski http://faculty.nps.edu/vitae/cgi-bin/vita.cgi?p=display_vita&id=1023568034 He has taken a real oceanography approach to Arctic sea ice melt, unlike many climate modelers - and he runs very high-resolution supercomputer simulations of the Arctic region (and tries to couple the boundaries to more mainstream full-planet GCM model runs), unlike the low-res GCM full-planet climate simulations most researchers run. Yes, turbulence, eddies and mixing of the halocline layers is very important at high resolutions, leading to much more sea ice bottom-melt than other simulations predict.
I agree that this site should just calmly discuss the details of Arctic sea ice and the science, measurements, theories, research papers and interpretations concerning this topic. I'm sure the Planetary Leaders have detailed, wise plans to deal with the rapidly escalating situation as soon as a "trigger point" warrants action, so we don't have to argue about it here:
And so it begins:
@GeoffBeacon | August 24, 2012 at 19:33 Let's hope Peter's fears about methane don't come to pass. I can well imagine what those fears are. I've been hearing about the 'clathrate gun' hypothesis for years, and the Permian–Triassic (P–Tr) extinction event (informally known as the Great Dying) which might have been an example. If humanity isn't ready to fight CO2 caused AGW, they are totally unprepared to even think about getting ready to fight a runaway methane event. Yeah, let's hope Professor Peter Wadham's fears about methane don't come to pass...
@Werther | August 25, 2012 at 00:48 Yes, the hatched portion in the Arctic Basin certainly seems to overlay the area I mentioned, but perhaps not quite far enough north in one location. And the entire hatched area in your map is larger than the area of < 1 meter thickness - it seems to include some 1.3 to 1.6 meter ice, if I'm reading your map correctly. Good call, for February - I'm just looking at the thinnest ice left, but maybe the model I'm looking at is way off, so the 160,000 sq. km. section I mentioned might be even smaller than the "thin ice left". We'll know soon enough. Again - why isn't at least ONE Cryosat-2 scientist getting some maps out there to curious bloggers ? Are they afraid they'll make one minor mistake in one map and the "skeptics" will whine and complain about a big hoax for five years ?
The whole section from 90°E to 130°E up to about 85°N seems to be mainly thin (less than 1 meter thick) sea ice: http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictnnowcast.gif This is a whole peninsula of ice that might melt away this summer: http://www.iup.uni-bremen.de:8084/ssmis/arctic_SSMIS_visual.png if ocean temperatures continue the bottom melt for a few more weeks. It would be nice if the Cryosat-2 people would join the party and let us know if models like the ARCc0 Ice Thickness product in the first link above were accurate, or too conservative, or totally wrong...
Several denialist blogs are now beginning to insist that an ice free Arctic is no problem, as it happened in the past. Well, there's scant evidence that it has happened at any time after the dawn of agriculture. Posted by: idunno | August 24, 2012 at 19:23 Exactly. The "skeptics" accept some entry in a journal from the 1800's about "Arctic sea ice being much less than usual" at one location on one date as some sort of proof that the Arctic was ice-free that year. Ergo, the Holocene coming to an end is no big deal, it's all part of "natural cycles", nothing to see here, move along... There is literally NOTHING that will convince such people that there is a problem with AGW.
@OldLeatherneck | August 24, 2012 at 16:34 2. Solar activity will be at it's maximum. Maximum ? Or did you just mean, higher than in 2012 ? http://sidc.oma.be/html/wolfmms.html http://sidc.oma.be/html/wolfaml.html I don't know if 2013 is necessarily the maximum sunspot activity year for this cycle. El Niño is in the Pacific Ocean - maybe it will bring warmer water up through the Bering Strait... There's natural variability every year, but the baseline warming keeps going up, up, up... the next big DROP (like 2005, 2007, 2012) might be the Big One - to a little stub of ice near Canada.
Next year, IARC-JAXA should change their Arctic Sea Ice Extent graph y-axis to start at 0, not 2. http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent_L.png In the end, it will just melt away quite suddenly. It might not be as early as 2013 but it will be soon, much earlier than 2040. -- Professor Peter Wadhams from Cambridge University
@Hans Kiesewetter | August 19, 2012 at 18:58 Thanks for the info - I didn't know the Alfred Wegener Institute research vessel was heading right towards that seafloor Gakkel Ridge, but you're quite right: http://expedition.awi.de/ http://www.awi.de/en/infrastructure/ships/polarstern/weekly_reports/all_expeditions/ark_xxvii/ark_xxvii3/ 54 international scientists and technical teams will investigate the biology, chemistry and physics of sea ice and the impact of sea ice loss on the entire Arctic Ocean system. The expedition IceArc will focus on the interactions between hydrography, ice physics, biogeochemistry and biodiversity in the Arctic system, from the sea ice to the deep-sea floor. By integrated process studies, sites in the central Arctic with no sea ice cover, at the ice edge and in multiyear sea ice will be compared. Ice-, ocean- and seafloor moorings will be deployed to observe sea ice thickness, circulation of Atlantic water and corresponding particle flux throughout the year. Sounds interesting. I wonder how detailed and 3D their "circulation of Atlantic water" studies will be. And yes, I hope they look at the Latptev Bite more closely...
Posted by: R. Gates | August 19, 2012 at 05:03 It is the global increase in energy in the Earth system caused by increasing greenhouse gases and the transport of that energy via various means to the Arctic that needs to be considered when analyzing the "cause" (as though there was a singular cause) of the decline in Arctic sea ice and the general warming of the Arctic. We know for example, that a great deal of energy is being transported to the Arctic via ocean currents as the global ocean energy content increases. Yes, that's exactly right. I would like to add that there is already a great mass of warm water underneath the sea ice, kept from touching the bottom of the ice by the haloclines (salinity gradients). I think the thickness is about 50 meters of low salinity, cold water separating the sea ice from 150 meters of water of steeply rising salinity and temperature. As the boundaries of the sea ice "continent" shrink each summer, exposing more Arctic ocean to wind and sun - and more frequent storms - this formerly placid halocline "barrier" gets breached in more and more places near the ice-open-water boundary, mixing deeper, warmer water with the surface, cold barrier water - then melting the sea ice above. So, in addition to the annual increase in energy that makes its way to the Arctic, there is the unleashing of energy that is already there, but formerly not being used for bottom melt. I think the "Laptev Bite" (long thin melt area) is an example of this. As the receding sea ice shore allows the new winds and currents to travel above 80° N in the Laptev Sea, the haloclines between the Lomonosov and Gakkel Ridges http://img402.imageshack.us/img402/9232/arcticoceanfloor.jpg are being vertically mixed: in recent summers, we see that long, thin meltout right above the 5000 meter deep gorge between the ridges. I think detailed modelling of the ocean current eddies in this location would show the surface layer mixing - right now it's just a hunch. Note the "bite" almost reaches up to 85° N now: http://www.iup.uni-bremen.de:8084/ssmis/arctic_SSMIS_visual.png
It looks like IARC-JAXA will break the record in less than two weeks: http://www.ijis.iarc.uaf.edu/seaice/extent/Sea_Ice_Extent.png Which is good, because there's a Presidential Election in the USA, and about half of adult Americans could use a wake-up call. I read this hilarious article about Jose Canseco twittering about climate change: http://www.mnn.com/earth-matters/climate-weather/blogs/who-knows-less-about-global-warming-than-jose-canseco-mitt-romne About Mitt Romney, it's said "elementary school students have a firmer grasp of the science involved". Probably true, for most of the older elementary school students. And about the GOP - "just because they take themselves so seriously doesn’t mean they aren’t a joke. Especially, it seems, when the subject is climate." (For people that don't follow American politics, that's Grand Old Party - Republicans - Willard Romney's party, and the party of idiot Senator Jimmy Inhofe of Oklahoma). If 2012 is the new 2007 (when the Arctic sea ice melt got some frantic coverage because it was disappearing "too fast") - perhaps the issue will get some weight in the November election. One can still hope.
Hi Neven. Nice to see such an important subject addressed so well on my first visit back this summer season. "Ocean heat flux, Maslowski" - pretty much my four favorite words in understanding the coming Arctic sea ice summer disappearance. I'll have to get more Parmigiano-Reggiano and popcorn for the 2012 season...
Toggle Commented Jun 30, 2012 on Ocean heat flux at Arctic Sea Ice
@Paul Klemencic | September 04, 2011 at 03:19 I looked at a longer set of JAXA SIE (sea ice extent) numbers, as you suggested a day or so ago (August 13 to August 30, a series of 18 2-day averages). I see what you mean by "the fit blows up". My first guesstimate of an initial sea ice extent to start the series led to some weird gyrations of daily sea ice extent after about 7 or 8 days of fitting. Again, I use "e12n" as the variable for "extent, August 12th, noon". I guesstimated the first value in the series as close to the midpoint between 2-day averages (reported JAXA values) for 8/12 and 8/13. The average of two days "noon" SIE is the reported JAXA values, e.g. 5700313 km^2 for 8/13/11. e12n - guesstimated at 5763906 (e12n + e13n)/2 = 5700313 --> e13n = 11400626 - e12n = 5636720 (e13n + e14n)/2 = 5624375 --> e14n = 11248750 - e13n = 5612030 (e14n + e15n)/2 = 5588281 --> e15n = 11176562 - e14n = 5564532 (e15n + e16n)/2 = 5548906 --> e16n = 11097812 - e15n = 5533280 (e16n + e17n)/2 = 5490625 --> e17n = 10981250 - e16n = 5447970 (e17n + e18n)/2 = 5410313 --> e18n = 10820626 - e17n = 5372656 (e18n + e19n)/2 = 5372656 --> e19n = 10745312 - e18n = 5372656 (e19n + e20n)/2 = 5335469 --> e20n = 10670938 - e19n = 5298282 (e20n + e21n)/2 = 5276719 --> e21n = 10553438 - e20n = 5255156 (e21n + e22n)/2 = 5173906 --> e22n = 10347812 - e21n = 5092656 (e22n + e23n)/2 = 5121563 --> e23n = 10243126 - e22n = 5150470 (e23n + e24n)/2 = 5084844 --> e24n = 10169688 - e23n = 5019218 (e24n + e25n)/2 = 5055781 --> e25n = 10111562 - e24n = 5092344 (e25n + e26n)/2 = 5009844 --> e26n = 10019688 - e25n = 4927344 (e26n + e27n)/2 = 4990156 --> e27n = 9980312 - e26n = 5052968 (e27n + e28n)/2 = 4964063 --> e28n = 9928126 - e27n = 4875158 (e28n + e29n)/2 = 4896563 --> e29n = 9793126 - e28n = 4917968 (e29n + e30n)/2 = 4796875 --> e30n = 9593750 - e29n = 4675782 But this whole exercise just shows that given the 2-day averages (reported JAXA data), it is non-trivial to solve for the internal, daily SIE data that gives rise to the reported data. For this example of 18 days data, there are 19 variables, e12n to e30n. This gives a system of 18 linear equations in 19 variables (i.e., the first equation is [e12n + e13n]/2 = 5700313 ) - an undetermined system. We provide the 19th equation by "guesstimating" an initial SIE - I wouldn't be surprised if MOST such guesses give solutions that "blow up" as you call it. But since JAXA says they are doing this 2-day averaging, then unless they are lying, there is at least ONE solution to these 18 equations that works fine. Probably more. But you're right, as you try to solve for longer and longer series of JAXA data, the tested solution is likely to "blow up" and oscillate wildly around the reported data. If you programmed a search of solution space for the initial "guess" (either all the integer values between two reported JAXA numbers at the beginning of a series, or maybe even include some fractions like .5, .25, .16666 since JAXA averages 3 or 4 measured SIE's of integer numbers of 12.5 km^2 pixels per day - I'm not sure how sensitive the solution is to fractions in the initial guess) I'm sure you could find the one, or more, solutions to this system of linear equations that seem plausible (e.g. no increases of SIE during summer melt). I would recommend searching a small solution space, between two JAXA numbers that are fairly close - it doesn't really matter where your initial guess is made, all the other values are derived from that guess. Your failure to find a good solution to 18, or 30, or 900 days of JAXA data doesn't mean they *aren't* doing simple 2-day averaging - it just means you haven't fully searched the solution space (for the initial guess) to solve this large system of linear equations. But you could, if you wanted to. It's probably easier to just ask JAXA for their internal data.
@Paul Klemencic | September 03, 2011 at 02:24 You can confirm this easily, if you tried. Pick three consecutive days of JAXA data, then run a model with all possible measured extents for the middle day, and use it, along with published two-day averages, to calculate the extents on either side of the three day period. You will find the published JAXA data result in a repeating pattern of very high melt days one day, with a very low or negative day the next. ============================================== I think you're confused about the JAXA claim of "However, we adopt the average of two days to achieve rapid data release." Here is some actual IARC-JAXA data for sea ice extent: 08,28,2011,4964063 08,29,2011,4896563 08,30,2011,4796875 They claim each released datapoint is an average of two days measured sea ice extent. Here's possible measured extents that would support 2 day averaging: e27n = 4977109.5 e28n = 4951016.5 e29n = 4842109.5 e30n = 4751640.5 e27n is "extent, for the 27th, noon" Average this extent with e28n - 2 days measured extents, averaged to give 4964063. Average e28n and e29n - you get 4896563. Average e29n and e30n - you get 4796875. I don't see any problems with "very high melt days one day, with a very low or negative day the next". You can think of this as measurements every noon, and the 2-day average of two noontime extents is the virtual value for the midnight between those noons - so, JAXA reports the virtual, average midnight values. JAXA also mentions 3 to 4 "preliminary extents" per day, so half a km^2 is not impossible if they are averaging 3 or 4 measurements to derive an official "noon measurement" that they then average with the next days official "noon measurement". It seems pretty straightforward. Perhaps I am missing some subtlety - it's rather late here...
A 60,000 km^2 drop is quite impressive - for comparison, last year on this day there was a drop of 18,906 km^2. I'm mainly interested in the rising ocean temperatures contributing to the thinning/disappearing sea ice (and the Argo system has little good data on the Arctic Ocean yet), the effects of all this new open ocean on the halocline and underwater currents, and the ice thickness maps - CryoSat-2 has been a disappointment this summer in their cautious data rollout. Given this lack of basic data, I haven't spent much time on the summer melt this year, but I do have my popcorn and Parmigiano-Reggiano ready to watch the final few weeks... This paper has a nice systematic way of looking at the summer sea ice melt - I like how they distinguish bottom melting from ocean dynamics ∆h-botO, and bottom melting from local atmospheric heating of the ocean ∆h-botA, for instance: http://psc.apl.washington.edu/zhang/Pubs/Steele_etal_2009JC005849.pdf Our analysis shows that top melt dominates total melt early in the summer, while bottom melt (and in particular, bottom melt due to ocean heat transport) dominates later in the summer as atmospheric heating declines. Bottom melt rates in summer 2007 were 34% higher relative to the previous 7 year average. The modeled partition of top versus bottom melt closely matches observed melt rates obtained by a drifting buoy. Bottom melting contributes about 2/3 of total volume melt but is geographically confined to the Marginal Ice Zone, while top melting contributes a lesser 1/3 of volume melt but occurs over a much broader area of the ice pack. (This paper looks at the Pacific Sector - the Atlantic side probably has much more early melt due to warm Atlantic heat convection) It's the bottom melt that is inexorably increasing year to year (since AGW dumps 90% of its heat into the oceans) and which will one summer make it all "disappear quite suddenly".
@Frivolousz21 | August 31, 2011 at 20:09 I am sorry you can not see this. This is one of the larger drops. And looks quite a bit larger then yesterdays. ... @Frivolousz21 | August 31, 2011 at 18:51 UB prelim map is out and all I can say it an other 100K drop is coming tonight maybe more. ===================================================== Well, maybe you expected more of a drop within the grayed-out East Siberian Sea due to winds. 08,31,2011,4737969 A 58,906 km^2 drop is quite impressive this late in the melt season, but it's no 100,000 km^2. Still, 2011 is close to dropping below 2008 now: 09,09,2008,4707813 km^2 was the minimum for 2008. As I said, Banks Island, the large Canadian island on the southern side of the westernmost part of the Northwest Passage, is 70,028 km^2. It helps to keep that area in mind when eyeballing the Bremen maps.
"So in the meantime we just have to salute those providing more accurate measuringtools!" I've been saluting the CryoSat-2 team since 8 April 2010 - but they've been pretty much ignoring me. http://tinyurl.com/3us8jsh
Toggle Commented Aug 31, 2011 on SIE 2011 update 18: ten yard line at Arctic Sea Ice