Monday, July 4, 2016
Sea ice affected by a lot of snow, THE END story
~Not to forget tidal action
NASA EOSDIS Barrow Strait rapid sea ice disintegration (June 29-July 3, 2016), notice the greyish looking capture pre and post breaking sea ice. That is the colour of thin sea ice, finally revealed by most of the snow melted or sublimated. It broke likely on about June 30 July 1. What is so special about that date? It is a few days before the new moon, a very potent time for stronger tidal driven sea current. This GIF animation demonstrates 2 major players, greater than normal snowfall created this ice earlier, and now despite being thinner, the snow preserved it to last a bit later. But Barrow Strait ice was terribly vulnerable, and a mere extra tidal current took care of it quite well with ease. The larger image provided by NASA allows us to hunt for similar looking ice on EOSDIS whenever available by cloud clearings, the "grey ice of doom" can be seen pretty much everywhere. None so clearer in the Canadian High Arctic at this time.WD July 4th, 2016
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PIOMAS shows the area north of Cornwallis Island at 1m+ thick on June 30. Now it's open water. I think PIOMAS may have overestimated the thickness :)
ReplyDeleteHi Kevin, good suggestion, the problem may be with bottom of sea ice rot, which may be 10 or 20 cm thick. Where krill find it neat to hide and eat. When drilling or an observation the bottom turns very soft and brownish, with either algae or krill enjoying their new temporary lodgings. In other words sea ice volume needs a correction calculation of sorts which no satellites can do. Thanks for your comment!
ReplyDeleteWhen you say "greater than normal snowfall created this ice earlier" can you give some rough dates? Are you talking about autumn when ice first appeared in the area, January when it was moving towards Baffin bay or february when it broke along the line it broke again now, forming a band of thinner ice. worldview link http://go.nasa.gov/29mMXWE
ReplyDeleteFall 2015 had a great deal of snow cover starting early, but its really October which had the mother load:
ReplyDeletehttps://worldview.earthdata.nasa.gov/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor,MODIS_Aqua_CorrectedReflectance_Bands721(hidden),MODIS_Terra_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_Bands367(hidden),MODIS_Terra_CorrectedReflectance_Bands721(hidden),Graticule,Coastlines&t=2015-10-10&v=-1813696,-1541568,-565440,-615872
NASA EOSDIS Just prior to sudden onset of ice over wide area.
A few days later:
https://worldview.earthdata.nasa.gov/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor,MODIS_Aqua_CorrectedReflectance_Bands721(hidden),MODIS_Terra_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_Bands367(hidden),MODIS_Terra_CorrectedReflectance_Bands721(hidden),Graticule,Coastlines&t=2015-10-14&v=-1813696,-1541568,-565440,-615872
Complete coverage of apparent sea ice, which was initiated by snowfall as well. A great deal of sea ice was formed quickly, morphed about by winds till setting into its final form. The snow spread out more evenly throughout winter. And on top of that, there was moisture influx from North Atlantic which did not go to Russia but mainly CAA throughout the winter.
I still am not sure what you mean. Are you saying this year had more snow cover on the ice? Does drifting of snow mean snow moves from older ice onto younger ice making it unimportant whether the ice was formed in October or February? Those are the questions I was raising in my comment, if I have not expressed myself clearly enough. Could you comment on the differences seen in the satellite images (721 bands and visible)
ReplyDelete"Are you saying this year had more snow cover on the ice?" Of course. But a lot of it was part of the new ice.
ReplyDelete"Does drifting of snow mean snow moves from older ice onto younger ice making it unimportant whether the ice was formed in October or February?"
Ice formed very rapidly right after greatest snowfall in October, new ice with a drifting current and strong winds is never stable. Its not a straight forward process, it involves many geophysical parameters.
"Could you comment on the differences seen in the satellite images (721 bands and visible)"
A superb photo , Is it readily available? Barrow Strait shows many stages of ice forming, moving, reforming according to the said parameters above. It also indicates much thinner ice.