Comments on: Arctic Sea Ice a Thin "Façade" http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/ Blogging the science and policy of global warming Mon, 16 Nov 2009 07:13:20 -0800 http://wordpress.org/?v=2.8.5.2 hourly 1 By: James Wang http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/comment-page-1/#comment-980 James Wang Tue, 01 Apr 2008 19:50:11 +0000 http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/#comment-980 Thanks for the link, David. Thanks for the link, David.

]]> By: davidzet http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/comment-page-1/#comment-978 davidzet Tue, 01 Apr 2008 15:33:23 +0000 http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/#comment-978 Here are <a href="http://aguanomics.com/2008/03/arctic-meltdown.html" rel="nofollow">some thoughts</a> on the geopolitics of global warmign and the Arctic Sea Here are some thoughts on the geopolitics of global warmign and the Arctic Sea

]]> By: Climate 411 » News from the Antarctic - Blogs & Podcasts - Environmental Defense Fund http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/comment-page-1/#comment-977 Climate 411 » News from the Antarctic - Blogs & Podcasts - Environmental Defense Fund Mon, 31 Mar 2008 22:08:30 +0000 http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/#comment-977 [...] month, while Arctic sea ice hits its annual wintertime high (such as it is - see last week’s post), Antarctic sea ice reaches its summertime [...] [...] month, while Arctic sea ice hits its annual wintertime high (such as it is – see last week's post), Antarctic sea ice reaches its summertime [...]

]]> By: James Wang http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/comment-page-1/#comment-976 James Wang Mon, 31 Mar 2008 21:36:35 +0000 http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/#comment-976 Hi kenzrw, You've raised an interesting point. Older sea ice could possibly have accumulated more soot, therefore having a darker color and absorbing more solar heat. However, ice albedo is affected by many other factors. For example, newly formed ice is grayish in color, and becomes whiter as it thickens. Snow that falls on ice affects the albedo--bare ice may reflect 50-70% of the sun's rays, while snow-covered ice can reflect up to 90%. To further complicate things, when the snow melts and forms ponds on the ice, the reflectivity of the surface can drop down to 75% to as low as 15%. Ice-free ocean is even darker in color--reflecting only 6% of the sun's rays. Considering that this winter's ice area is lower than average, any increase in whiteness of the ice due to a lack of soot is not likely to offset the increase in area of dark water. The NASA scientists said that we'd need a string of cold years for the ice to fully recover. Hi kenzrw,

You've raised an interesting point. Older sea ice could possibly have accumulated more soot, therefore having a darker color and absorbing more solar heat.

However, ice albedo is affected by many other factors. For example, newly formed ice is grayish in color, and becomes whiter as it thickens. Snow that falls on ice affects the albedo–bare ice may reflect 50-70% of the sun's rays, while snow-covered ice can reflect up to 90%. To further complicate things, when the snow melts and forms ponds on the ice, the reflectivity of the surface can drop down to 75% to as low as 15%.

Ice-free ocean is even darker in color–reflecting only 6% of the sun's rays. Considering that this winter's ice area is lower than average, any increase in whiteness of the ice due to a lack of soot is not likely to offset the increase in area of dark water.

The NASA scientists said that we'd need a string of cold years for the ice to fully recover.

]]> By: Environmental Capital - WSJ.com : Green Ink: All About Iraq http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/comment-page-1/#comment-969 Environmental Capital - WSJ.com : Green Ink: All About Iraq Fri, 28 Mar 2008 12:17:39 +0000 http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/#comment-969 [...] radically change the way they live and do business. [...] radically change the way they live and do business.

]]> By: kenzrw http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/comment-page-1/#comment-968 kenzrw Thu, 27 Mar 2008 22:22:23 +0000 http://blogs.edf.org/climate411/2008/03/27/arctic_ice_thin/#comment-968 One thing to consider on the refrozen sea ice is its' increased whiteness and thus increased albedo, or reflection of the sunlight. I've seen the older ice photos that shows the ice brown or almost black from soot and particulates, so it aborbes more sunlight. But the new ice doesn't have that much soot yet, so in theory it should reflect more sunlight. Couldn't this slow down the warming a little this summer? Especially if it's not sunny and clear as many days as it was in 2007 and if the winds don't blow out more ice into warmer waters? One thing to consider on the refrozen sea ice is its' increased whiteness and thus increased albedo, or reflection of the sunlight. I've seen the older ice photos that shows the ice brown or almost black from soot and particulates, so it aborbes more sunlight. But the new ice doesn't have that much soot yet, so in theory it should reflect more sunlight. Couldn't this slow down the warming a little this summer? Especially if it's not sunny and clear as many days as it was in 2007 and if the winds don't blow out more ice into warmer waters?

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