Comments on: Arctic Sea Ice Melt Speeds Up

By: CPslashM

CPslashM — Tue, 16 Jul 2013 17:06:34 +0000

The PIOMAS volume anomaly graph http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.png for the last couple of years appears to show volume recovery in the winter, i.e. heat entering Arctic in summer is balanced by heat leaving in the following winter. I would expect a dark Arctic sea to be covered with at least thin ice in winter. However, the amount of heat entering in successive summers appears to be increasing. OK, so it’s only three summers but if the trend continues I suspect that when an area is totally ice-free, the heat will still be coming in, so temperatures may rise rapidly. A fly in the ointment is pan evaporation demonstrates that solar radiation is a major factor in evaporation, so heat will be lost to the atmosphere. This may then condense on the Greenland ice sheet.

I’m tired and I’m waffling. Apologies.

By: CPslashM

CPslashM — Tue, 16 Jul 2013 16:43:04 +0000

I’m with Roger Caws in treating the whole thing as energy balance. What I don’t get is the relevance of sea ice extent. If 16% of the sea is covered in ice, 84% is absorbing sunlight. If the ice is spread out evenly, according to NSIDC it’s 100% extent. If 14% of the sea area is covered with ice but spread evenly with the rest of the ice clumped together, it’s 2% extent. Same ice area, same volume, same 84% absorbing the suns rays. The only things I can think of are the local weather may change, and clumping may change local ice thickness.

By: Greg Laden

Greg Laden — Mon, 15 Jul 2013 16:33:03 +0000

There are chemical engineers looking at this and the physics and chemistry are well understood, young man!

By: Roger Caws

Roger Caws — Mon, 15 Jul 2013 16:24:35 +0000

Why are there no chemical engineers looking at all this. Looking at extent of ice, thickness of ice, water temperature and air temperature and albedo. You need to be looking at heat flow then it will all make sense. If that ice is going to disappear then you need to provide so many Kilo Joules of heat. If the sun (modified by adsorption) and the heat in the warm current flows provide the required amount then we get water. If not it stays as ice. Can’t someone amongst all these climatologists do the model properly please. And in case you ask It is a young man’s game and I am yesterday’s generation.

By: John Samuel

John Samuel — Thu, 11 Jul 2013 14:49:24 +0000

I like having Les around. He makes me feel much smarter by comparison.

By: John McKay

John McKay — Thu, 11 Jul 2013 04:56:53 +0000

That makes me feel a little better.

The fact that willing tools like Les still exist temper that a bit, but I’ll take what I can get.

By: Greg Laden

Greg Laden — Thu, 11 Jul 2013 03:11:06 +0000

Its been factored in. You are right, the thickness is even more important and I’m planning a post on that soon. Here’s an example of a graph showing thickness and volume:
http://commons.wikimedia.org/wiki/File:Arctic_Sea_Ice_area_thickness_and_volume_trends.png

The thick ice tends to form an anchor for the new ice each year, so when there is less thick ice, that also slows reformation, which probably translates around the annual cycle to faster remelting.

By: John McKay

John McKay — Thu, 11 Jul 2013 02:40:38 +0000

Are there equivalent charts for thickness? We have scattered information since the late fifties when US and USSR subs started making crossings. The ice is getting thinner, but by how much and for how long should be an important variable. Areas that don’t clear off, becoming easily measurable by satellite pictures, have still been losing ice. The rapid collapse we’re seeing now has to be partly because of a decades long thinning. The eastern Arctic is behaving more like North Atlantic sea ice than true pack ice.

The thought that’s forming in my head as I write this is that we’ve been invisibly losing thousands of cubic miles of ice every year without a clear measurement of that fact (unless you know of one). Those thousands of cubic miles of cold water would have had a dampening effect on global warming. But as we run out of ice not only will the changed albedo of the North become a problem, but one of our air conditioners will be turned off.

Please tell me this has already been factored into the climate models.

By: Greg Laden

Greg Laden — Tue, 09 Jul 2013 16:57:00 +0000

In reply to jane. I don't think Les was talking about seasons. And yes, the arctic ice is currently at close to the second lowest level and on track to equal or exceed last year's record breaking melt!

By: jane

jane — Tue, 09 Jul 2013 16:52:53 +0000

“Antarctic ice and arctic ice are not in inverse link-step”

Sure they are – whenever it’s summer up here and the ice melts, it’s winter down there and the ice grows. And every year, people claim that expanding Antarctic ice means there’s no global warming. Can someone find a Stark to explain the mechanism to Les?

What you might have asked Les, by the way, is if Arctic temperatures this melt season have really been “below average” (compared to what time range?), then isn’t it quite alarming that the decrease in ice cover has been faster than average? Doesn’t that imply that something else is going on, like say the ocean itself heating up?