tag:blogger.com,1999:blog-5337555368793819627.post2431916907716451669..comments2023-06-07T09:04:36.390-04:00Comments on More Grumbine Science: Sea Ice Predictions 2012 Open PollRobert Grumbinehttp://www.blogger.com/profile/10783453972811796911noreply@blogger.comBlogger12125tag:blogger.com,1999:blog-5337555368793819627.post-68635235190801781242012-06-18T13:34:29.714-04:002012-06-18T13:34:29.714-04:00My ensemble of Gompertz predictions seemed to do r...My ensemble of Gompertz predictions seemed to do reasonably well last year -- slightly low for NSIDC extent, right on for Uni Bremen extent, close for NSIDC area, and too high for PIOMAS volume. It seems worth sticking with this approach for at least another year, so I'm going with these predictions for 2012:<br />NSIDC extent, 4.3<br />NSIDC area, 3.0<br />PIOMAS volume, 4.0<br />CT area 1-day, 2.7<br />Graphs and a description of the method (including confidence intervals) Neven's:<br />http://neven1.typepad.com/blog/2012/06/naive-predictions-of-2012-sea-ice.htmlL Hamiltonhttp://pubpages.unh.edu/~lch/noreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-14804608275645300932012-06-11T14:24:55.173-04:002012-06-11T14:24:55.173-04:00For the June SEARCH call I sent off my guess of 4....For the June SEARCH call I sent off my guess of 4.3 for NSIDC, motivated by a simple Gompertz model shown graphically at Neven's place:<br />http://neven1.typepad.com/blog/2012/06/naive-predictions-of-2012-sea-ice.htmlL Hamiltonhttp://pubpages.unh.edu/~lch/noreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-80071960006123065022012-06-05T00:30:43.104-04:002012-06-05T00:30:43.104-04:00I am going to go with 4.9 just because I often cal...I am going to go with 4.9 just because I often call myself a skeptic on these blogs under the assumption that the bering freeze will slow things down a little bit, and I like the idea of those who believe ACC is a scam gloating once again that not breaking the record minimum is proof that that the arctic is in full recovery mode.tonylearnshttps://www.blogger.com/profile/15168161576867493109noreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-34005156280856025112012-05-25T17:58:56.558-04:002012-05-25T17:58:56.558-04:00Hi Bob,
I'll bet you Q50 that the September i...Hi Bob,<br /><br />I'll bet you Q50 that the September ice is less than 4.15 M km^2. Judging by the latest from http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png we are heading for a record low ice extent this year.<br /><br />Cheers, AlastairAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-26666442662146066372012-05-24T11:37:56.614-04:002012-05-24T11:37:56.614-04:00"Sea Ice Prediction"
-- by Horatio Alger..."Sea Ice Prediction"<br />-- by Horatio Algeranon<br /><br />Ice will melt<br />And then refreeze<br />In summer and winter<br />If you please.<br /><br />Don't believe?<br />Then prove it wrong<br />Won't have to wait<br />So very long.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-19637506095970348302012-05-16T09:02:12.834-04:002012-05-16T09:02:12.834-04:00Now that IJIS is back online, I'm doubting whe...Now that IJIS is <a href="http://neven1.typepad.com/blog/2012/05/ijis-is-back.html" rel="nofollow">back online</a>, I'm doubting whether I should put up a poll for IJIS daily minimum extent, or NSIDC monthly average September extent (just like SEARCH).<br /><br />The former is more fun to track on a daily basis in September.Nevenhttps://www.blogger.com/profile/15413215743703093876noreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-36133997935758065902012-05-16T05:41:31.350-04:002012-05-16T05:41:31.350-04:00I've updated the model with data up to Sept 20...I've updated the model with data up to Sept 2011 and the revised prediction for Sept 2012 is 4.584938 +/- 1.031588 M km^2.Dikran Marsupialnoreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-38233317729312366332012-05-15T10:22:09.611-04:002012-05-15T10:22:09.611-04:00Please do feel free to quote the original comment ...Please do feel free to quote the original comment at SkS, but make sure you mention it only uses 1979-2009 data, so it is quite a long range forecast by now!<br /><br />The plus/minus is a Bayesian 95% credible interval, but I expect the 2 standard deviation confidence interval would be pretty much the same.<br /><br />I also made a <a href="http://www.skepticalscience.com/greenman-2011-sea-ice-minimum.html#64299" rel="nofollow">sea ice volume prediction</a> as well, but again it wasn't a serious prediction, just experimenting with the GP software. I very much hope the sea ice volume prediction is pessimistic!Dikran Marsupialnoreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-70530273660144521692012-05-14T19:13:41.645-04:002012-05-14T19:13:41.645-04:00Alastair:
:-) Very likely. The question being in...Alastair:<br />:-) Very likely. The question being in which year?<br /><br />Given how close my prediction for this year is (the statistical one, that is) to last year, and yours being the same, how about going with the same bet as last year? Over/under 4.15 M km^2, 50 quatloos?<br /><br />Dikran:<br />Interesting method. Ok if I snarf your SkS comment and incorporate it in the body of the article above? (Duly credited, of course.) Or, if you'd prefer, you could write up something specifically for this purpose.<br /><br />One question, though -- is your plus/minus one or two standard deviations? The figure looks high for it being only 1.Robert Grumbinehttps://www.blogger.com/profile/10783453972811796911noreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-12968726032864572172012-05-14T15:56:31.095-04:002012-05-14T15:56:31.095-04:00Back in September 2001 at SkS I made a prediction ...Back in <a href="http://www.skepticalscience.com/greenman-2011-sea-ice-minimum.html#64243" rel="nofollow">September 2001</a> at SkS I made a prediction for 2012 of 4.614637 M km^2 (+/- 1.128915). However this is based on data up to 2010, so updating the model might change that somewhat.<br /><br />The prediction is a purely statistical one, using a Gaussian process regression model.Dikran Marsupialnoreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-79395684954290007062012-05-10T08:12:40.224-04:002012-05-10T08:12:40.224-04:00Hi Bob,
I will just go with the estimate I made l...Hi Bob,<br /><br />I will just go with the estimate I made last year - 3.9 M km^2. With the decling trend in Arctic sea ice extent, if I stick with that value then one year I am bound to be correct!<br /><br />Moreover I don't believe it is possible to calculate what the September ice extent will be. Who could have calculated April's ice extent shown here: <a href="http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png" rel="nofollow">http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png</a>?<br /><br />Cheers, Alastair.Alastairhttps://www.blogger.com/profile/15152292130415788120noreply@blogger.comtag:blogger.com,1999:blog-5337555368793819627.post-70982036178624131282012-05-10T07:24:11.265-04:002012-05-10T07:24:11.265-04:00This comment has been removed by the author.Alastairhttps://www.blogger.com/profile/15152292130415788120noreply@blogger.com