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Post by radiant on Aug 29, 2009 14:06:50 GMT
Hmm, JAXA chart suggests fall in ice extent is nearing an end. Arctic temperature shown at ocean.dmi.dk/arctic/meant80n.uk.php is below freezing but seems to be holding up. Looking back at earlier years, the last time arctic temperatures held up like this was 2007 and the El Nino year of 1998 The temperatures seem to be dipping down again and all day sun is about to end above N80. www.ogimet.com/cgi-bin/gsynop?zona=artico&base=bluem&proy=orto&ano=2009&mes=08&day=29&hora=12&vte=Te&enviar=Ver(There are two buoys on that chart near Alaska that are under reading by a large amount from time to time) Spitsbergen web cams are already getting sunsets. I saw in the last few days that the ice in the bays in northwest Greenland just broke up so obviously the melt goes on. Away from fresh water areas like the North west passage where the flow and mixing to have full salinity is probably fairly low, we must be weeks off a freeze up for now - with not much ice needing to be lost to make our efforts to create increased cooling come to nothing. My late comers prediction/guess of ice just fractionally above 2008 is looking fairly good so far
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Post by Purinoli on Aug 29, 2009 15:45:59 GMT
The next report is due out next week. It will be interesting to see how NSIDC tries to get itself some wiggle room. We still have 3 more days of data to come in from August. If the current trend continues, it is going to be difficult for NSIDC to be both scientific, and maintain the warmaholic dogma. Here's my prediction: "August finished with the third lowest ice extent since the dawn of the satellite age, surpassed in its lowness only by the record setting and polar bear devastating years of 2007 and 2008. Save the whales." And if they realy release such kind of report, then we could compare it with nice joke from 60 ties : On the athletic track ( 100 m sprint) there were Chruschow, Nikita and Kennedy, John. The outcome was predicted, but not fairly reported from all. US news papers : Nikita last, John the winner. Moscow Pravda : Nikita 2 nd, John only one better then last he he Regards from Slovenia and apologize for grammatics, E. is not my 1st language
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Post by radiant on Aug 29, 2009 16:34:03 GMT
Here's my prediction: "August finished with the third lowest ice extent since the dawn of the satellite age, surpassed in its lowness only by the record setting and polar bear devastating years of 2007 and 2008. Save the whales." And if they realy release such kind of report, then we could compare it with nice joke from 60 ties : On the athletic track ( 100 m sprint) there were Chruschow, Nikita and Kennedy, John. The outcome was predicted, but not fairly reported from all. US news papers : Nikita last, John the winner. Moscow Pravda : Nikita 2 nd, John only one better then last he he Regards from Slovenia and apologize for grammatics, E. is not my 1st language The way it seems to work in the west is that you tell everybody 'since satellite records began in 1979' when in fact useable records began for canadian ice survey areas in the 1960's. So you can imagine the same satellites were observing northern russia and alaska too. www.cmos.ca/IceHistory.pdfIce Central first received the TIROS satellite images in the 1960s. The low resolution power of these early sensors limited their usefulness to showing presence of ice, general ice edge/limit when ice was very diffuse, indications of general concentration within the pack area, In 1961 you could analyse ice in the St lawrence river area www.photolib.noaa.gov/bigs/spac0089.jpg Sea ice analysis in the Gulf of St. Lawrence showing dramatic change in one weekAnd by 1965 there were polar satellites orbiting Devon Island September 16th 1965 www.photolib.noaa.gov/htmls/spac0145.htmAnd what we learn from the definative review of the research available in 1988 www.amazon.com/Little-Ice-Age-Jean-Grove/dp/0415014492was that northern hemisphere ice was growing from the 50's to 1973. And that ship based observation records were reliably kept all thru the last 120 years or so. Sort of convenient then that the maximum extent shown by the earlier perfectly ok satellite data and decades of other methods is not available for us to see so we can come to our own conclusions. There is definately a farmyard smell about this ice topic! If i had access to a university library i could have some fun i think. This paper is sort of interesting! pubs.aina.ucalgary.ca/arctic/Arctic49-3-235.pdfThe worst ice year in modern times was 1972, when only Lancaster Sound and its nearest approaches cleared. Weather conditions during that summer were controlled by an elongate low-pressure system that stretched from the Kara Sea across the Pole to a low centred in the Labrador Sea (Alt et al., 1985). This pressure system set up a northwesterly air flow across most of the Arctic Archipelago, driving ice into the channels and depressing summer temperatures by 1– 4˚C. Exceptional ice clearance occurred in 1962, when even M’Clintock Channel (but not Viscount Melville Sound) cleared. Persistent southwesterly winds driven by a high-pressure system over the central Arctic mainland aided exportation of ice to Baffin Bay and increased ablation in the M’Clintock Channel region (Alt et al., 1985).Today we know that Bellot strait is fully open and back in 1934? it was passable although full of ice and 'they went for it'. And yet the guy who went thru, who was chief of Hudson bay company in the area later cheerfully said more or less the company did not like to report ice conditions because it would encourage competition. And we know that Larson in 1944 was able to pass thru the part of the canadian arctic that was impassable in the exceptionally passable modern times year of 1962 - in the context of a study talking about ice over the last few thousand years Another favourite being the study that showed the hudson bay was not ice free as popularly believed in winter, while simultaneously from elsewhere we know that ice melted until the 1940's and then began freezing again in the 1950's until 1973 and the study showing 'it was a myth' it was unfrozen in winter was done in 1969!
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Post by hilbert on Aug 29, 2009 17:25:44 GMT
I can understand why the measured values might be different, but shouldn't the graphs be qualitatively the same? Why does Nansen show recent levelings off, but JAXA a more regular decline?
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Post by radiant on Aug 29, 2009 17:34:43 GMT
I can understand why the measured values might be different, but shouldn't the graphs be qualitatively the same? Why does Nansen show recent levelings off, but JAXA a more regular decline? Two different methods of calculation. Ice area shows visible total actual summed together ice area over 15% concentration excluding water between ice using their own method. Ice extent shows 'spread of ice' with all ice over 15% concentration counting as 100% ice using their own method. So if there is no water between the central mass of ice they will be the same if they use the same method and exclude the same under 15% of ice and water. Neither method takes account of quantity of ice so if all of the ice is bunched together to form ice ridges many metres high the amount of ice is shown as being less.
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Post by Purinoli on Aug 29, 2009 18:02:59 GMT
Two different methods of calculation.
Ice area shows visible total actual summed together ice area over 15% concentration excluding water between ice using their own method.
Ice extent shows 'spread of ice' with all ice over 15% concentration counting as 100% ice using their own method.
So if there is no water between the central mass of ice they will be the same if they use the same method and exclude the same under 15% of ice and water.
Neither method takes account of quantity of ice so if all of the ice is bunched together to form ice ridges many metres high the amount of ice is shown as being less-------------------- I frequently check Actic Ice here : nsidc.org/arcticseaicenews/ ( not sure if this is otimal source) and once a month copy picture to my file. I don't know what accuracy one can expect from this data, seems to me much less then "official SSN count" which itself is also not very exact No. But seems to me that we see a second year in the row of accelerating an average ice area in the Arctics. Due to weather patterns, salinity caused by streams etc there can be some decreasing on one side and increasing on other side but the trend of last 3 years is to my mind obvious unless the way data are measured/recalculated is wrong. Next 10 weeks will be very interesting. One point of interest is time of rebound ( if it is before Sept 10 could mean stronger upward trend to my mind). If not, all is still opened.
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Post by kiwistonewall on Aug 30, 2009 3:18:27 GMT
Puzzle: Give the letters in order for 2006,2007,2008,2009 (All are NOAA images for the last full week in August) There are 2 years from the 90's to add some confusion. 2007 is easy to spot: So? What is the answer (I'll post the solution tomorrow) - no cheating by looking at the NOAA charts... ('C' has no ice showing in Hudson bay - just in case you thought I had cut off Hudson Bay to confuse..)
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Post by msphar on Aug 30, 2009 3:39:31 GMT
I'll go with FBEC just on memory without researching.
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Post by msphar on Aug 30, 2009 3:55:14 GMT
I think its time to predict the eventual low point. I suspect it will occur inside the next 3 weeks. I'll pick Sept 10th to coincide with hurricane season peak.
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Post by kiwistonewall on Aug 30, 2009 12:12:36 GMT
Solution is: 2006: C 2007: B 2008: E 2009: D
A: is 1998 F: is 1995
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Post by Purinoli on Aug 30, 2009 15:12:40 GMT
Solution is: 2006: C 2007: B 2008: E 2009: D A: is 1998 F: is 1995 Ops, looks like 08/2009 Arctic ice fills the biggest area of all pictures from A-F. Just guessing, maybe I should imply some SW or print pics, cut out red areas and weigh them on my analytical balance ( method which was used sometimes before computer era to determine area of peaks in chromatography). Can you give us some data about area in square km for those pics? Sorry to bother, anyway I'll try to get them, but don't know the source. Thks and best regards
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Post by radiant on Aug 30, 2009 17:32:00 GMT
Those NW passage boats: Interesting to watch M/S Bagan hugging the coast towards Tuk to eventually exit the Beaufort sea this year? when canadian ice data shows significant ice a bit further on from their present position and temperatures have fallen again. northwestpassagefilm.com/arctic/Silent Sound has reached Bellot strait Fiona is now not so far behind Bagan. share.findmespot.com/shared/faces/viewspots.jsp?glId=0DjUAlZJFegMqAtQZ9PN7Ibet1q0yYuMMEven Perithia is now showing a plot not far from Fiona. The frozen brits will give up if they get to Gjoa. A small open cockpit Norwegian boat coming from east west passage is being escorted by armed russians to get their paperwork sorted out acting under orders from Moscow. www.seilmagasinet.no/id/33192.0this Swede has a rather cool video of arctic life www.skinnarmo.com/The show goes on!
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Post by kiwistonewall on Aug 30, 2009 20:56:47 GMT
. Can you give us some data about area in square km for those pics? Sorry to bother, anyway I'll try to get them, but don't know the source. Thks and best regards NOAA is the source, and they (quite wisely?) don't play the extent/area game. ;D Part of the reason for the "slow down" in the ice "melt" at this time of year is that the more northerly areas are starting to re-freeze, while the more southerly areas continue to melt - when these are in balance, we get no further decline until the major re-freeze begins. Ice expanding near Resolute too in last few days.
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Post by kiwistonewall on Aug 31, 2009 6:44:44 GMT
The way to Eureka is freezing up fast. This is apparently the last chart (of this level of detail) for the year - I assume that they have decided the freeze has come, and this will not be navigable this year. I don't think any icebreakers got through this year, the first time since the Eureka station was founded. If any one can disprove this with some authority (i.e. that a supply ship made it this year, or that there was another year when resupply didn't make it.) I would be most interested. Either way, I don't think we'll see any headlines on this. ice-glaces.ec.gc.ca/prods/WIS36CT/20090830180000_WIS36CT_0004547694.gifSo the refreeze (up around 75-80N) seems to be here - but that is "normal" for end of August that far North. Melting will still occur further South, but the balance point (the minimum ice extent) can't be far away.
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Post by radiant on Aug 31, 2009 7:06:28 GMT
The way to Eureka is freezing up fast. This is apparently the last chart (of this level of detail) for the year - I assume that they have decided the freeze has come, and this will not be navigable this year. I don't think any icebreakers got through this year, the first time since the Eureka station was founded. If any one can disprove this with some authority (i.e. that a supply ship made it this year, or that there was another year when resupply didn't make it.) I would be most interested. Either way, I don't think we'll see any headlines on this. ice-glaces.ec.gc.ca/prods/WIS36CT/20090830180000_WIS36CT_0004547694.gifSo the refreeze (up around 75-80N) seems to be here - but that is "normal" for end of August that far North. Melting will still occur further South, but the balance point (the minimum ice extent) can't be far away. Resupply looks possible from the satellite image of 28th August which somehow i ended up naming 30th of sept s680.photobucket.com/albums/vv161/Radiant_2009/?action=view¤t=30sept.pngThe blue grey colour is ice. White over water is cloud. Grey can also be cloud. I dont have access to high resolution. Here is a video of last years resupply www.youtube.com/watch?v=WFCnGmfe80Y&NR=1
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