WidreMann Posted November 7, 2011 Share Posted November 7, 2011 Here's the sea ice chart you asked for.. tied for record lowest extent. Pixel counting off of the NSIDC maps shouldn't be used in lieu of the actual sea ice algorithms. It's not that interesting given the number of blips like that show up in even the last few years' ice records. If it lasts for another week, then we need to talk. Link to comment Share on other sites More sharing options...
ArtRosen Posted November 7, 2011 Share Posted November 7, 2011 Here's the sea ice chart you asked for.. tied for record lowest extent. Pixel counting off of the NSIDC maps shouldn't be used in lieu of the actual sea ice algorithms. Do you have anything from 1979 onwards? Link to comment Share on other sites More sharing options...
BethesdaWX Posted November 7, 2011 Share Posted November 7, 2011 Here's the sea ice chart you asked for.. tied for record lowest extent. Pixel counting off of the NSIDC maps shouldn't be used in lieu of the actual sea ice algorithms. Why are you comparing 30% DMI graphs to a map which references 15% extent? That makes no sense, use NORSEX 15% extent to compare. Until we build back the multi year ice that was flushed from the basin the 30% extent data will lag compared to 2007 & beforehand since winter 2008 did most of the dirty work, and it wouldn't be a good comparison anyway. And it'll take time to restore thr MY ice because the thinner ice melts off more in the summer, and with less albedo more radiation is absorbed, SSTAs increase, and the entire arctic basin warms. That's why you see the huge + anomalies in the arctic as a result of ice loss, so it's kind of like a positive feedback mechanism to ice loss. We've had recovery in the 3-year ice in this September update advancing by the year so you can see where this is going. Link to comment Share on other sites More sharing options...
skierinvermont Posted November 7, 2011 Share Posted November 7, 2011 Why are you comparing 30% DMI graphs to a map which references 15% extent? That makes no sense, use NORSEX 15% extent to compare. Until we build back the multi year ice that was flushed from the basin the 30% extent data will lag compared to 2007 & beforehand since winter 2008 did most of the dirty work, and it wouldn't be a good comparison anyway. And it'll take time to restore thr MY ice because the thinner ice melts off more in the summer, and with less albedo more radiation is absorbed, SSTAs increase, and the entire arctic basin warms. That's why you see the huge + anomalies in the arctic as a result of ice loss, so it's kind of like a positive feedback mechanism to ice loss. We've had recovery in the 3-year ice in this September update advancing by the year so you can see where this is going. NORSEX hasn't updated in over a week that's why. NSIDC, which is also 15%, shows near record lows as well. The reason 30% is low has nothing to do with MY ice. Ice doesn't need to be MY to be 30% concentration. Anything that is not very recently frozen in the last week or two and near the ice edge will be 70%+ concentration mostly near 100%. There's almost no difference between 15% and 30%. If a year is last in one, it is likely to be last in the other. Link to comment Share on other sites More sharing options...
skierinvermont Posted November 7, 2011 Share Posted November 7, 2011 Do you have anything from 1979 onwards? The charts are usually not presented like that because it gets to be too many lines to see, but here is the one I know of. You can also get estimates of pre-1979 extent from Walsh and Chapman 2001 which is a topic in the CC forum. http://www.americanw...n-sea-ice-data/ Link to comment Share on other sites More sharing options...
wxmx Posted November 7, 2011 Share Posted November 7, 2011 Understanding the mechanism which the proposed higher snow cover Eurasian anomalies work would help us analyze the real meaning of the current conditions of the NHEM cryosphere. It is proposed that the greater/lower snowcover anomalies in the Eurasian region promote a higher/lower anomalies in the SLP around the Eurasian region. Looking at the highest snowcover anomalies in this region for October shows that there are higher than normal pressures Which tend to migrate west and then north, as the Artic Sea freezes. OTOH, low snowcover anomalies tend to promote lower pressures in E Russia early in the season And those pressure anomalies usually propagate thru the AO region, which promote a +AO for the winter season So what's in store for winter 2011-2012. Snow cover anomalies were low for the first 3 weeks of October, with a sudden recovery to above normal the last week of the month, which brought the average to just below normal. SLP anomalies in the month were not good for those looking for high latitude blocking during DJF But this average tell us little of what really happened. ...during low level anomalies ...and after the sudden increase in snow cover. I think the coin is still in the air, and we should monitor how the Siberian high behaves for the rest of November, as it is known to promote planetary waves that might disrupt the nightly polar jet and consequent high latitude blocking. Link to comment Share on other sites More sharing options...
BethesdaWX Posted November 7, 2011 Share Posted November 7, 2011 NORSEX hasn't updated in over a week that's why. NSIDC, which is also 15%, shows near record lows as well. The reason 30% is low has nothing to do with MY ice. Ice doesn't need to be MY to be 30% concentration. Anything that is not very recently frozen and near the ice edge will be 70%+ concentration mostly near 100%. There's almost no difference between 15% and 30%. If a year is last in one, it is likely to be last in the other. Umm.....No.....the obvious deviation between DMI 30% and NORSEX 15% has been there all season and always will be, look at the DMI site vs the NORSEX site between 2007 and 2011 on each, and it's clear that DMI has run lower via less MY/high concentration ice than NORSEX which measures 15% extent. You don't think that a doubling in the extent % especially during a period of +AO during gain-season would matter? Or the Ice freezing up along the land masses apart from the main body doesn't affect it? http://ocean.dmi.dk/...ver_current.png http://arctic-roos.o...mi1_ice_ext.png It's obvious, and the fact that the maps posted here had us above 2010 last week as did NORSEX, while the DMI did not, confirms the fact that 30% extent is irrelavent to compare to 15% now in a Year-to-year basis. Why do you think the DMI graph usually peaks after the NORSEX and Once-used AMSR-E? NORSEX 15% had us above last years (2010) at 15% extent last week before it stopped updating, which falls in line with the Maps provided on this site (obvious given the square-kilometer # too), while the DMI site had us well below 2010 during that same timeframe. Which one matches up? NORSEX....because it uses the same extent % that the maps do. . Link to comment Share on other sites More sharing options...
skierinvermont Posted November 7, 2011 Share Posted November 7, 2011 It's not that interesting given the number of blips like that show up in even the last few years' ice records. If it lasts for another week, then we need to talk. I'm not saying it's an issue.. in fact low sea ice has been hypothesized to lead to a more -NAO (see Francis 2009 among others). It has been near record low values the last 6 months. Link to comment Share on other sites More sharing options...
skierinvermont Posted November 7, 2011 Share Posted November 7, 2011 Umm.....No.....the obvious deviation between DMI 30% and NORSEX 15% has been there all season and always will be, look at the DMI site vs the NORSEX site between 2007 and 2011 on each, and it's clear that DMI has run lower via less MY/high concentration ice than NORSEX which measures 15% extent. You don't think that a doubling in the extent % especially during a period of +AO during gain-season would matter? Or the Ice freezing up along the land masses apart from the main body doesn't affect it? http://ocean.dmi.dk/...ver_current.png http://arctic-roos.o...mi1_ice_ext.png It's obvious, and the fact that the maps posted here had us above 2010 last week as did NORSEX, while the DMI did not, confirms the fact that 30% extent is irrelavent to compare to 15% now in a Year-to-year basis. Why do you think the DMI graph usually peaks after the NORSEX and Once-used AMSR-E? NORSEX 15% had us above last years (2010) at 15% extent last week before it stopped updating, which falls in line with the Maps provided on this site (obvious given the square-kilometer # too), while the DMI site had us well below 2010 during that same timeframe. Which one matches up? NORSEX....because it uses the same extent % that the maps do. . The issue has nothing to do with the 15% vs 30%. It has to do with other differences in the algorithms. NSIDC, which is also 15%, ran way lower than NORSEX for most of 2011. In early September, NSIDC was tied with 2007, while NORSEX was nearly 500k above. NORSEX also shows all sorts of unrealistic physically impossible spikes and dips (esp. look at 2008). I don't trust NORSEX, never have. If you want to use it, go ahead. I'm not going to. I think the issue may be that NORSEX still uses a 25km resolution, while all the others use 12.5km or less. Link to comment Share on other sites More sharing options...
mitchnick Posted November 7, 2011 Share Posted November 7, 2011 Understanding the mechanism which the proposed higher snow cover Eurasian anomalies work would help us analyze the real meaning of the current conditions of the NHEM cryosphere. It is proposed that the greater/lower snowcover anomalies in the Eurasian region promote a higher/lower anomalies in the SLP around the Eurasian region. Looking at the highest snowcover anomalies in this region for October shows that there are higher than normal pressures Which tend to migrate west and then north, as the Artic Sea freezes. OTOH, low snowcover anomalies tend to promote lower pressures in E Russia early in the season And those pressure anomalies usually propagate thru the AO region, which promote a +AO for the winter season So what's in store for winter 2011-2012. Snow cover anomalies were low for the first 3 weeks of October, with a sudden recovery to above normal the last week of the month, which brought the average to just below normal. SLP anomalies in the month were not good for those looking for high latitude blocking during DJF But this average tell us little of what really happened. ...during low level anomalies ...and after the sudden increase in snow cover. I think the coin is still in the air, and we should monitor how the Siberian high behaves for the rest of November, as it is known to promote planetary waves that might disrupt the nightly polar jet and consequent high latitude blocking. this is a great and informative post; thanks for your effort but I remain positive because I recall early-mid OCT, 2009 was below normal snow and then it jumped to way above this link (that's been posted before in this thread) has a few graphs going back to 2007 that reflect the deficiency in the early-mid Oct. period interestingly, in early NOV, 2009 (or thereabouts) snow cover went way below normal then shot back up http://moe.met.fsu.edu/snow/ I guess what I'm saying is, I'm happy to be above last year at this time, we ended OCT above normal, and it has remained that way into NOV Link to comment Share on other sites More sharing options...
BethesdaWX Posted November 7, 2011 Share Posted November 7, 2011 The issue has nothing to do with the 15% vs 30%. It has to do with other differences in the algorithms. NSIDC, which is also 15%, ran way lower than NORSEX for most of 2011. In early September, NSIDC was tied with 2007, while NORSEX was nearly 500k above. NORSEX also shows all sorts of unrealistic physically impossible spikes and dips (esp. look at 2008). I don't trust NORSEX, never have. Pretty sure the NSIDC graph is a model-derived dataset while one is observational, and if so regardless observation trumps modeling or at least if you're comparing one set to another you shouldn't differ. And between NORSEX and the American satellite that was de-activated, one uses 25km box-reso and the other 15km box-reso is why you see variation in percise detail depending on the box size and coverage differential between the two. The map data being "pixel counted" in this thread is also derived from satellite observation, and one dataset happens to match up with that while the other doesn't...so if you're looking to compare the map with observation data you should know what to do. EDIT: Re: PIOMAS, wrong system in mind. Link to comment Share on other sites More sharing options...
skierinvermont Posted November 7, 2011 Share Posted November 7, 2011 Understanding the mechanism which the proposed higher snow cover Eurasian anomalies work would help us analyze the real meaning of the current conditions of the NHEM cryosphere. It is proposed that the greater/lower snowcover anomalies in the Eurasian region promote a higher/lower anomalies in the SLP around the Eurasian region. Looking at the highest snowcover anomalies in this region for October shows that there are higher than normal pressures ...and after the sudden increase in snow cover. I think the coin is still in the air, and we should monitor how the Siberian high behaves for the rest of November, as it is known to promote planetary waves that might disrupt the nightly polar jet and consequent high latitude blocking. Very cool post.. pretty cool to see the way that works out. Isn't the mechanism basically that the Siberian +SLP anomalies put pressure on the stratosphere and disrupt it or something like that? If so, is there any way to tell if the late October +SLP anomalies did disrupt the stratosphere? Link to comment Share on other sites More sharing options...
skierinvermont Posted November 7, 2011 Share Posted November 7, 2011 Pretty sure the NSIDC graph is a model-derived dataset No. NSIDC is observational data just like all the others and used 12.5km resolution or finer, like all the other sources except NORSEX which still uses the old 25km resolution. Link to comment Share on other sites More sharing options...
BethesdaWX Posted November 7, 2011 Share Posted November 7, 2011 The reason 30% is low has nothing to do with MY ice. Ice doesn't need to be MY to be 30% concentration. Anything that is not very recently frozen in the last week or two and near the ice edge will be 70%+ concentration mostly near 100% .Yes but old ice does not drift or change configuration like younger ice does, younger ice has a higher saltwater concentration while the older ice tends to become more freshwater based over time, which effects the level it sits on the water and how quickly it melts/drifts/so on and so forth. There is almost never a 15% extent made of old ice, but young ice certainly would and there could very well be a difference there. I just want to compare 15% with 15%, to lay it simply. Better than an ulterior method of 15% vs 30%. No. NSIDC is observational data just like all the others and used 12.5km resolution or finer, like all the other sources except NORSEX which still uses the old 25km resolution. Yes I believe I clarified that in the edit, but I still don't understand why if you don't like NORSEX (despite it correlating better to the pixel-maps) why you'd post DMI over NSIDC. NSIDC has updated. Lower reso hyas never been a problem with you RE: GISS and it's lower reso, so I don't know why you'd bring it up here since any differential would be minute anyway. Anyway I'm done with my ranting, I have a pet peeve in valid comparisons. Link to comment Share on other sites More sharing options...
antietam Posted November 7, 2011 Share Posted November 7, 2011 It should be stated that 2/3rds of Canada is way above mormal with the Canadian Arpechelo running 15-20C above normal. That is 27-36F for those who don't know. There isn't much cold in Canada for them. Yet at all. Places are 0c to -10c and should be -10c to -28c If we were this far below normal it would be - 25c to -45c. does this have an affect later on I have no idea. But I know it affects cold shots coming down from Northern Canada. That kind of warm air coming over lack of snow cover has no chance. Models with th current Colorado system were showing a much much colder mid range solution day 5-8 for my area when climo was a larger factor with the model solutions. As we got closer they warmed up big time even with the connection to the colder air up there. This summer I followed arctic sea ice daily to close. This happened all summer in the arctic. The cold in mid range never materialized or was much weaker. I have no way to prove this. Bit I bet if Canada was under temps the same as now but on the cold anomaly side I bet the cold air connection would be much larger and easier to obtain. Since 1995 my area has seen a tremendous cold and snow drought overall. When I go look at historic monthly temp anomalies for October and November that was around the time really after 97 or 98 that the cold months on the fall started to flip They keep getting Warmer year after year. All I am saying is we should look for a correlation that maybe snow cove and sea ice have on temps. I'm guessing it's olr leaving the Earth causing a lot of it that might not be there otherwise. Really? And you are in St. Louis. This is surprising to me, Terre Haute Indiana, just east on I-70, starting with 1999, has had 9 of its last 12 Octobers below average and 3 above average. For November it is 5 colder and 7 warmer. Are you sure your readings are accurate at STL, or is sprawl and concrete contributing to your warming over there? Link to comment Share on other sites More sharing options...
griteater Posted November 8, 2011 Share Posted November 8, 2011 Very informative post wxmx...good work. Link to comment Share on other sites More sharing options...
WidreMann Posted November 8, 2011 Share Posted November 8, 2011 Understanding the mechanism which the proposed higher snow cover Eurasian anomalies work would help us analyze the real meaning of the current conditions of the NHEM cryosphere. It is proposed that the greater/lower snowcover anomalies in the Eurasian region promote a higher/lower anomalies in the SLP around the Eurasian region. Looking at the highest snowcover anomalies in this region for October shows that there are higher than normal pressures Which tend to migrate west and then north, as the Artic Sea freezes. OTOH, low snowcover anomalies tend to promote lower pressures in E Russia early in the season And those pressure anomalies usually propagate thru the AO region, which promote a +AO for the winter season So what's in store for winter 2011-2012. Snow cover anomalies were low for the first 3 weeks of October, with a sudden recovery to above normal the last week of the month, which brought the average to just below normal. SLP anomalies in the month were not good for those looking for high latitude blocking during DJF But this average tell us little of what really happened. ...during low level anomalies ...and after the sudden increase in snow cover. I think the coin is still in the air, and we should monitor how the Siberian high behaves for the rest of November, as it is known to promote planetary waves that might disrupt the nightly polar jet and consequent high latitude blocking. Certainly an interesting pattern and it makes sense. Does the research bear this out, or is it just something you've thought of yourself? Either way, looks grim for the upcoming winter. Sigh. Link to comment Share on other sites More sharing options...
easternsnowman Posted November 8, 2011 Share Posted November 8, 2011 Certainly an interesting pattern and it makes sense. Does the research bear this out, or is it just something you've thought of yourself? Either way, looks grim for the upcoming winter. Sigh. It depends upon location for this winter. Link to comment Share on other sites More sharing options...
WidreMann Posted November 8, 2011 Share Posted November 8, 2011 It depends upon location for this winter. You go far enough north and you'll almost always do okay. It's gonna suck for 40s, though. Link to comment Share on other sites More sharing options...
wxmx Posted November 8, 2011 Share Posted November 8, 2011 this is a great and informative post; thanks for your effort but I remain positive because I recall early-mid OCT, 2009 was below normal snow and then it jumped to way above this link (that's been posted before in this thread) has a few graphs going back to 2007 that reflect the deficiency in the early-mid Oct. period interestingly, in early NOV, 2009 (or thereabouts) snow cover went way below normal then shot back up http://moe.met.fsu.edu/snow/ I guess what I'm saying is, I'm happy to be above last year at this time, we ended OCT above normal, and it has remained that way into NOV Like I said in my post, I think the coin is in the air, the snow cover anomalies for October aren't strong enough to side on the cold or the warmth, but knowing how the mechanism work should help us still gather data, though the precursor is centered in October, but we know nature knows little about arbitrarily imposed time boundaries. If the Siberian high grows and migrates north for the rest of the month (wrt to normal), then we could think that the late snow cover growth did it's dirty work. Of course there are many other variables we should take into account, but I (and we in this thread) am focusing mostly on snow cover anomalies in the Eurasian region in the fall. Very cool post.. pretty cool to see the way that works out. Isn't the mechanism basically that the Siberian +SLP anomalies put pressure on the stratosphere and disrupt it or something like that? If so, is there any way to tell if the late October +SLP anomalies did disrupt the stratosphere? Yep, Judah Cohen's research shows that there's an energy transfer from the troposphere to the stratosphere, aiding in the warming and consequent polar vortex weakening. Very informative post wxmx...good work. Thanks griteater, I was mostly trying to show a visual of Cohen's work. Certainly an interesting pattern and it makes sense. Does the research bear this out, or is it just something you've thought of yourself? Either way, looks grim for the upcoming winter. Sigh. I based my post mostly on Cohen's work. It's just the gist of it, since it might help people visualize how snow cover anomalies work one way or another. This paper has been linked by usedtobe a couple of times in this thread. It's quite short and totally edible. Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted November 8, 2011 Share Posted November 8, 2011 Norsex is like using the NGM or current Nogaps. Its an old algorithm that has been proven in every peer reviewed study since AMSRE that the bootstrap(jaxa) artist(asi)"bremen" and NASA team(NSIDC) Are much better and all within a very small error margin of each other. Using pixel counting for ice when their are tools far greater is not advisable. Using norsex for anything out side of a real time trend checker will give you bad results ussually 500k off. This happend because grid Res is 25km which is old old in sea ice tracking land. As follows: Nic: 24km upconverted to 4 km. Jaxa: 12.5km Bremen: 6.25km, 3.125km(regional) NSISDC: 24km post converted to 4km during pixel correction process. DMI: 10km Link to comment Share on other sites More sharing options...
LithiaWx Posted November 8, 2011 Share Posted November 8, 2011 Understanding the mechanism which the proposed higher snow cover Eurasian anomalies work would help us analyze the real meaning of the current conditions of the NHEM cryosphere. It is proposed that the greater/lower snowcover anomalies in the Eurasian region promote a higher/lower anomalies in the SLP around the Eurasian region. Looking at the highest snowcover anomalies in this region for October shows that there are higher than normal pressures Which tend to migrate west and then north, as the Artic Sea freezes. OTOH, low snowcover anomalies tend to promote lower pressures in E Russia early in the season And those pressure anomalies usually propagate thru the AO region, which promote a +AO for the winter season So what's in store for winter 2011-2012. Snow cover anomalies were low for the first 3 weeks of October, with a sudden recovery to above normal the last week of the month, which brought the average to just below normal. SLP anomalies in the month were not good for those looking for high latitude blocking during DJF But this average tell us little of what really happened. ...during low level anomalies ...and after the sudden increase in snow cover. I think the coin is still in the air, and we should monitor how the Siberian high behaves for the rest of November, as it is known to promote planetary waves that might disrupt the nightly polar jet and consequent high latitude blocking. wow, this is a very informative post, thanks for posting this. Link to comment Share on other sites More sharing options...
SVT450R Posted November 11, 2011 Share Posted November 11, 2011 Last year compared to this year. If anyone is looking for other year comparisons just post what you are looking for. Link to comment Share on other sites More sharing options...
nycsnow Posted November 11, 2011 Share Posted November 11, 2011 Last year compared to this year. If anyone is looking for other year comparisons just post what you are looking for. Looks like a lot more snow cover this year Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted November 11, 2011 Share Posted November 11, 2011 Is there any site that tracks snow depth and age? Link to comment Share on other sites More sharing options...
BethesdaWX Posted November 11, 2011 Share Posted November 11, 2011 Is there any site that tracks snow depth and age? I'm not sure what you're saying...snowcover age? It's always one year, depth varies year to year. But the trend in snowcover has been up up and up since the PDO flip Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted November 11, 2011 Share Posted November 11, 2011 Fresh snow cover reflectsmuch more sun light then melting or older snow. Quiye a bit of the snow cover in Canada is very thin. Tthis is the only reason to track the snow. So it would be nice if we had reliable data on this. Link to comment Share on other sites More sharing options...
LithiaWx Posted November 12, 2011 Share Posted November 12, 2011 Fresh snow cover reflectsmuch more sun light then melting or older snow. Quiye a bit of the snow cover in Canada is very thin. Tthis is the only reason to track the snow. So it would be nice if we had reliable data on this. I haven't read all of these fully but there are plenty more reasons to track snow other than the age/albedo effect of old and new snow. http://web.mit.edu/j..._SaitoGRL03.pdf http://journals.amet.../2008JCLI2505.1 http://journals.amet...1175/JCLI4241.1 http://www.nws.noaa....ohen_062211.pdf Link to comment Share on other sites More sharing options...
Alpha5 Posted November 12, 2011 Share Posted November 12, 2011 Fresh snow cover reflectsmuch more sun light then melting or older snow. Quiye a bit of the snow cover in Canada is very thin. Tthis is the only reason to track the snow. So it would be nice if we had reliable data on this. Its actually Eurasian snow cover that is shown to have a good correlation with winters in the US, not canadian snow Link to comment Share on other sites More sharing options...
The_Global_Warmer Posted November 12, 2011 Share Posted November 12, 2011 So let's take out snows effect on temperatures by reflecting more energy back into space. What else does it do? That is important to track? Link to comment Share on other sites More sharing options...
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