tag:blogger.com,1999:blog-1367053740188758246.post3326013357852015759..comments2023-06-21T00:39:34.443-07:00Comments on Dosbat: The CT Area June CrashChris Reynoldshttp://www.blogger.com/profile/16843133350978717556noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-1367053740188758246.post-2845865719900036882013-06-11T09:18:49.304-07:002013-06-11T09:18:49.304-07:00Sorry for being late in getting back to you Peter....Sorry for being late in getting back to you Peter.<br /><br />I agree that the concentration drop seems to be reflecting a real concentration drop. MODIS seems to support that. <br /><br />I think I need to look at what's going on in the atmosphere on NCEP/NCAR.Chris Reynoldshttps://www.blogger.com/profile/16843133350978717556noreply@blogger.comtag:blogger.com,1999:blog-1367053740188758246.post-53915860103610717572013-06-09T01:03:18.348-07:002013-06-09T01:03:18.348-07:00Interesting situation going on right now, with a s...Interesting situation going on right now, with a sudden concentration drop in the central arctic basin, but no matching drop in the peripheral seas. So, is this a real drop due to divergence and opening up of leads, or a false drop due to surface melt ponding? <br /><br />My feeling is that it can't be melt ponding. Surface melt should proceed from the outside inwards towards the centre - I can't see any plausible scenario where the central basin became melt ponded before the peripheral seas. <br /><br />So, is it real - perhaps due to the effects of the cyclone fragmenting and diverging the thin ice cover? Likely so, at least in part: but it could also simply be sensors being misled by thick cloud.Peterhttps://www.blogger.com/profile/12559721137290332762noreply@blogger.comtag:blogger.com,1999:blog-1367053740188758246.post-53028738734407002752013-05-22T21:19:20.067-07:002013-05-22T21:19:20.067-07:00OK, a bit off topic, but it bears repeating that w...OK, a bit off topic, but it bears repeating that we do know something about cloud behavior ;-) . I do agree that spring and early summer are much more variable and the amount of melt pools depends very much on warm air intrusions during the high solar radiation.Oalehttps://www.blogger.com/profile/14032383453035968859noreply@blogger.comtag:blogger.com,1999:blog-1367053740188758246.post-59185694369224832082013-05-22T13:19:35.181-07:002013-05-22T13:19:35.181-07:00Oale,
Those changes are the result of increasing ...Oale,<br /><br />Those changes are the result of increasing open water. As I showed in my post on Autumn changes, everything is in response to reduced sea ice.<br /><br />Kevin,<br /><br />Have you checked out CT Area daily minimum series and PIOMAS volume from ice over 2m in April series?<br /><br />Brr, it's getting cold out here.<br /><br />(I'm thinking in terms of 2010: The Year We Made Contact, the scene on the Radio Telescope - Must watch that film again!)<br /><br />Anyway if you've not checked it out, I'll post in a day or two, almost ready.Chris Reynoldshttps://www.blogger.com/profile/16843133350978717556noreply@blogger.comtag:blogger.com,1999:blog-1367053740188758246.post-48396600092336018292013-05-21T21:25:46.385-07:002013-05-21T21:25:46.385-07:00well, after the sun has gone down in autumn equino...well, after the sun has gone down in autumn equinox the open sea wil produce enough water vapor for clouds. these cannot be high clouds as there is little turbulence in the dark arctic. so the effect is likely to be (in the freezing period) that cloud albedo has no effect (no sun) but the cloud backradiation is still there. once a thick enough ice cover has formed the water vapor is likely to get less, skies clear and the freezing process speeds up. this is at least my explanation for the fast build up of ice area seen in recent novembers.Oalehttps://www.blogger.com/profile/14032383453035968859noreply@blogger.comtag:blogger.com,1999:blog-1367053740188758246.post-42849795253732652742013-05-21T16:31:38.596-07:002013-05-21T16:31:38.596-07:00Chris, I believe the deciding factor in how large...Chris, I believe the deciding factor in how large the melt will be is cloud altitude, optical depth, and fraction --- i.e., what we normally refer to as weather :)<br /><br />But even if we were given a crystal ball with the relevant numbers filled in, I'm not sure we could make a prediction that would classify as anything more than a WAG. Clouds can be either net positive or negative and I don't think we really have a handle on where the demarcation line lies for any of the relevant properties. Complicated by the fact that it likely varies depending on both the latitude and the albedo of the surface beneath the clouds.<br /><br />Given the coarse resolution of the models, clouds really remain a mystery. <br /><br />Kevin O'Neillhttps://www.blogger.com/profile/06692943768484857724noreply@blogger.comtag:blogger.com,1999:blog-1367053740188758246.post-27377708663550597842013-05-21T09:26:19.586-07:002013-05-21T09:26:19.586-07:00Peter,
Thanks for adding detail and summing up th...Peter,<br /><br />Thanks for adding detail and summing up the post so astutely.Chris Reynoldshttps://www.blogger.com/profile/16843133350978717556noreply@blogger.comtag:blogger.com,1999:blog-1367053740188758246.post-59484439883125501452013-05-21T01:17:04.017-07:002013-05-21T01:17:04.017-07:00It's clearest in the Laptev where there was an...It's clearest in the Laptev where there was an anomaly drop of something like 200k in the last couple of days of May, which then stopped dead with essentially no further change in area throughout the whole of June. We all saw (and extensively discussed) the "blue ice" appearance of the melt ponding at the time.<br />http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.8.html<br /><br />As you say, this early crash is not a genuine ice loss <i>at the time of the crash</i> - however the ice that falsely drops out of detection during the crash is exactly the ice that's most likely to melt out by the end of the year (first-year, highly-ponded).Peterhttps://www.blogger.com/profile/12559721137290332762noreply@blogger.com