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Post by Ratty on Jul 28, 2014 7:50:54 GMT
Nautonnier, please correct me if I am wrong here. With insolation, I think the rippled surface of water would always enjoy a relatively high proportion of high incident angle radiation, which would be absorbed. Hence reflection would be less effective. The crical angle for total reflection would be important here. Ice/snow, on the other hand, would presumably always reflect a high proportion of the incident radiation. This would be an interesting research topic! So Doug, you want to make waves? I'm sure we could put up a reasonable case for some grant money. We could go and watch the ice melt too. I have a thick sweater and a beanie.
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Post by nautonnier on Jul 28, 2014 14:08:15 GMT
Nautonnier, please correct me if I am wrong here. With insolation, I think the rippled surface of water would always enjoy a relatively high proportion of high incident angle radiation, which would be absorbed. Hence reflection would be less effective. The crical angle for total reflection would be important here. Ice/snow, on the other hand, would presumably always reflect a high proportion of the incident radiation. This would be an interesting research topic! It has been researched for example see this discussion on Albedo . Note that the albedo (reflectivity ) during the northern summer is very high.
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Post by cuttydyer on Jul 28, 2014 17:30:44 GMT
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Post by sigurdur on Jul 29, 2014 2:20:15 GMT
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Post by sigurdur on Jul 29, 2014 2:20:53 GMT
No thanks Cutty. You can video while you are on this cruise and share it with us in 2020 when you get home.
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Post by douglavers on Jul 29, 2014 4:14:42 GMT
Nautonnier Thank you for the albedo reference. www.eoearth.org/view/article/51cbece37896bb431f68e3e9/Snow clearly provides the highest albedo, followed by sea ice. Glacier ice is lower, probably reflecting ingrained dirt. Water is interesting. At small zenith angles [sun high in sky] it absorbs nearly all incident radiation. For larger angles, the range quoted was 0.1 to 1.0 . I suspect the latter was for a sun low in the sky with a calm sea. The critical angle would be very much in play here, with almost total reflectance. The other figures are probably a reflection of wave height [?]. There would be a high probability of an incoming photon striking the side of a wave at an effective low zenith angle. Of much greater significance, as the extent is larger, is the highish albedo of thick cloud. Even small differences in cloud cover over our planet would make a big difference to absorbed solar energy.
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Post by douglavers on Jul 29, 2014 4:18:27 GMT
Cuttydyer
I think the problem will be obtaining cancellation insurance for the trip.
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Post by Ratty on Jul 29, 2014 4:31:34 GMT
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Post by cuttydyer on Jul 29, 2014 6:41:14 GMT
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Post by sigurdur on Jul 29, 2014 12:56:44 GMT
Cutty: Aw shucks. It would have been good to have a known person aboard to report how stuck you are. Wise move tho, getting a wide berth for the voyage............
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Post by nautonnier on Jul 29, 2014 17:13:30 GMT
Well they could still do it - boots rucksacks and langlauf - maybe not proving quite what they wanted to prove, and they would have to cope with those re-emergent polar bears
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Post by sigurdur on Jul 29, 2014 17:59:28 GMT
Well they could still do it - boots rucksacks and langlauf - maybe not proving quite what they wanted to prove, and they would have to cope with those re-emergent polar bears Yep, the Polar Bear numbers have increased 50% in the past 15 years. It is amazing what a hunting ban will do isn't it?
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Post by neilhamp on Jul 30, 2014 0:00:17 GMT
The sailing boats are still optimistic of progress cornellsailing.com/2014/07/change-of-scenery/The latest ice chart issued daily by the Canadian Ice Service shows the 15 mile-wide inlet to be choked by ice, so I called the local vstation of the Royal Canadian Mounted Police (RCMP) to find out if Arctic Bay itself was accessible. The helpful duty officer confirmed that it was free of ice but could give no indication on the ice situation furher out. We shall therefore approach the area with caution, and if we are lucky and there is an open lead along the shore, we hope to be able to reach our destination
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Post by cuttydyer on Jul 30, 2014 7:51:33 GMT
The sailing boats are still optimistic of progress cornellsailing.com/2014/07/change-of-scenery/The latest ice chart issued daily by the Canadian Ice Service shows the 15 mile-wide inlet to be choked by ice, so I called the local vstation of the Royal Canadian Mounted Police (RCMP) to find out if Arctic Bay itself was accessible. The helpful duty officer confirmed that it was free of ice but could give no indication on the ice situation furher out. We shall therefore approach the area with caution, and if we are lucky and there is an open lead along the shore, we hope to be able to reach our destination Far from plain sailing: Link: www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e A small flotilla; that should keep the coastguard busy:
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dh7fb
New Member
Posts: 25
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Post by dh7fb on Jul 30, 2014 12:18:14 GMT
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