How To Restore Arctic Sea Ice Mass

[Vergent]

I wouldn't even attempt to fill in the strait, I would just build a surface barrier and attach it to the floor, you can't stop the water flow beneith the ice for obvious reasons.

You better hurry up, very soon there will be no MYI to save.

[Jonger]

You better hurry up, very soon there will be no MYI to save.

So PIOMAS predicts a full melt out in 3 years?

[PhillipS]

I wouldn't even attempt to fill in the strait, I would just build a surface barrier and attach it to the floor, you can't stop the water flow beneith the ice for obvious reasons.

If I understand your concept, you're talking about some sort of floating boom, similar in concept to those used to contain oil spills or to corral floating logs at sawmills, only much larger in size. One end anchored to the NE Greenland coast and the other end tethered to the seafloor some distance, say 100 km, out in the Fram strait. Since its purpose is to hold back sea ice floes from passing through the Fram Strait so it would only need to extend five meters or so below the surface. Is that along the lines of what you had in mind?

It is an interesting idea, but where it runs aground is in the strength needed to hold back all of that sea ice. One m3 of ice weighs a metric ton 1,000 kg), 1 km2 of sea ice 2 meters thick weighs 2,000,000 tons (2 * 10 ⁹ kg), 100,000 km2 of sea ice 2 meters thick (a ball park value for the amount of sea ice your boom would have to contain) would weigh 200,000,000,000 tons (200 gigatons or 200 * 10 ¹² kg).

Think back to your basic physics equations of motion - the momentum (p) of that 200 gigaton (m) ice pack moving at, say, 0.1 m/s (0.36 km/hr) (v) would be:

p = m * v = (200 * 10 ¹² kg) * (0.1 m/s) = 20 * 10 ¹² kgm/s (also expressed as newton seconds)

That a lot of momentum. To bring the sea ice to a halt your barrier has to be strong enough to provide an opposing force. Again going back to intro physics,

F = m * a since we have to stop the ice pack traveling 0.1 m/s, for simplicity I'll set the acceleration to 0.1 m/s2

F = (200 * 10 ¹² kg) * (0.1 m/s2) = 20 * 10 ¹² newtons

High strength steel cable has a rating of around 1 * 10 ⁹ newtons/m2 and let's use a safety factor of 10. The cross-sectional area of a steel cable strong enough to stop the hypothetical 100,000 km2 ice pack would be:

((20 * 10 ¹² newtons) / (1 * 10 ⁹ newtons/m2)) * 10 = 200 * 10 ³ m2

which, if it were a round cable, would have a diameter of about 500 meters. Of course, the figure would be higher for a cable at right angles to the motion of the sea ice (think of an arresting cable on an aircraft carrier).

Still think your concept is feasible?

[Jonger]

If I understand your concept, you're talking about some sort of floating boom, similar in concept to those used to contain oil spills or to corral floating logs at sawmills, only much larger in size. One end anchored to the NE Greenland coast and the other end tethered to the seafloor some distance, say 100 km, out in the Fram strait. Since its purpose is to hold back sea ice floes from passing through the Fram Strait so it would only need to extend five meters or so below the surface. Is that along the lines of what you had in mind?

It is an interesting idea, but where it runs aground is in the strength needed to hold back all of that sea ice. One m3 of ice weighs a metric ton 1,000 kg), 1 km2 of sea ice 2 meters thick weighs 2,000,000 tons (2 * 10 ⁹ kg), 100,000 km2 of sea ice 2 meters thick (a ball park value for the amount of sea ice your boom would have to contain) would weigh 200,000,000,000 tons (200 gigatons or 200 * 10 ¹² kg).

Think back to your basic physics equations of motion - the momentum (p) of that 200 gigaton (m) ice pack moving at, say, 0.1 m/s (0.36 km/hr) (v) would be:

p = m * v = (200 * 10 ¹² kg) * (0.1 m/s) = 20 * 10 ¹² kgm/s (also expressed as newton seconds)

That a lot of momentum. To bring the sea ice to a halt your barrier has to be strong enough to provide an opposing force. Again going back to intro physics,

F = m * a since we have to stop the ice pack traveling 0.1 m/s, for simplicity I'll set the acceleration to 0.1 m/s2

F = (200 * 10 ¹² kg) * (0.1 m/s2) = 20 * 10 ¹² newtons

High strength steel cable has a rating of around 1 * 10 ⁹ newtons/m2 and let's use a safety factor of 10. The cross-sectional area of a steel cable strong enough to stop the hypothetical 100,000 km2 ice pack would be:

((20 * 10 ¹² newtons) / (1 * 10 ⁹ newtons/m2)) * 10 = 200 * 10 ³ m2

which, if it were a round cable, would have a diameter of about 500 meters. Of course, the figure would be higher for a cable at right angles to the motion of the sea ice (think of an arresting cable on an aircraft carrier).

Still think your concept is feasible?

I considered the strength of the cables obviously, my solution in theory would be to stagger the barriers, starting farther into the arctic and working toward the fram Strait. If the ice melts out as PIOMAS indicates, we would have an open ocean to work with. The barriers could be created to create a surface series of friction barriers to inhibit the eventual exit out of the strait (the natural flow path).

I'll play with this idea and see how feasible it is, but if PIOMAS is accurate, the arctic will be ice free in 3 years and we will have to get creative.

[PhillipS]

I considered the strength of the cables obviously, my solution in theory would be to stagger the barriers, starting farther into the arctic and working toward the fram Strait. If the ice melts out as PIOMAS indicates, we would have an open ocean to work with. The barriers could be created to create a surface series of friction barriers to inhibit the eventual exit out of the strait (the natural flow path).

I'll play with this idea and see how feasible it is, but if PIOMAS is accurate, the arctic will be ice free in 3 years and we will have to get creative.

PIOMAS didn't predict an ice free summer arctic in three years (2015) - that's just where an exponential curve fitted to the data reaches zero. There are other kinds of curves that could be used and other factors that effect arctic ice melt.

But even an arctic ice free in late summer in the future will still have a winter refreeze every year and sea ice will still flow out the Fram Strait. The Bering Strait is both shallower and shorter than the Fram so it would be easier to bridge. Still incredibly tough, but easier than the Fram.

[Jonger]

PIOMAS didn't predict an ice free summer arctic in three years (2015) - that's just where an exponential curve fitted to the data reaches zero. There are other kinds of curves that could be used and other factors that effect arctic ice melt.

But even an arctic ice free in late summer in the future will still have a winter refreeze every year and sea ice will still flow out the Fram Strait. The Bering Strait is both shallower and shorter than the Fram so it would be easier to bridge. Still incredibly tough, but easier than the Fram.

Would damming up the Bering really do much though? Seems like most ice is heading out of the Fram.

[SVT450R]

Would damming up the Bering really do much though? Seems like most ice is heading out of the Fram.

Yea it wouldn't do much the Fram is the gateway.

[Jonger]

I hate using the word damming.... There is no way to dam up the fram, it would have to be a series or surface barriers to restrain ice. It would probably require a series of barriers and a full international effort, we need the ice for wildlife and earth temperature control, its something to consider at least if the ice melts out.

[PhillipS]

Would damming up the Bering really do much though? Seems like most ice is heading out of the Fram.

I honestly don't know what the global effect of damming the Bering Strait would be in today's environment - but remember, sea levels were low enough during the glacials to make the Bering Strait dry land. People and animals wandered back and forth over it for thousands of years.

Perhaps someone with paleoclimate knowledge can shed some light on the question.

[Msalgado]

I don't get all this talk about damming anything. Before anything else, if simple carbon cuts are not politically feasible how on earth is some large Geo engineering operation?

But besides all of that, it all comes down to simple conservation of energy. The melting of ice takes energy from one part of the earth system and moves it to another. If you are somehow able to stop the melting of the ice, all you do is build up the energy in other parts of the system. So you damn it up, and the ice doesn't flow out, but now oceanic heat that was melting the ice is now building up within the water and eventually the ice melts anyway.

[Msalgado]

I considered the strength of the cables obviously, my solution in theory would be to stagger the barriers, starting farther into the arctic and working toward the fram Strait. If the ice melts out as PIOMAS indicates, we would have an open ocean to work with. The barriers could be created to create a surface series of friction barriers to inhibit the eventual exit out of the strait (the natural flow path).

I'll play with this idea and see how feasible it is, but if PIOMAS is accurate, the arctic will be ice free in 3 years and we will have to get creative.

Wait, so your advocating having the ice go against these barriers - slowing down through friction - as a means of keeping the ice from melting?

Do a simple experiment. Rub your hands together for 15-20 seconds. Do they feel hotter? You're basically advocating turning kinetic energy into thermal energy. The ice is moving and you can't simply make that energy disappear. It has to go somewhere, and if you stop that ice from moving all you're going to do is create a good deal of heat.

[Jonger]

I don't get all this talk about damming anything. Before anything else, if simple carbon cuts are not politically feasible how on earth is some large Geo engineering operation?

But besides all of that, it all comes down to simple conservation of energy. The melting of ice takes energy from one part of the earth system and moves it to another. If you are somehow able to stop the melting of the ice, all you do is build up the energy in other parts of the system. So you damn it up, and the ice doesn't flow out, but now oceanic heat that was melting the ice is now building up within the water and eventually the ice melts anyway.

The majority of myi is just rolling out of the fram, not just melting in place.

Also, let's say we 100% stop all co2 emissions today, we still would have 400ppm floating around for 200 years... I'm not totally convinced that is the cause of the warming, but whatever the cause, the arctic ice is melting.

[Jonger]

Wait, so your advocating having the ice go against these barriers - slowing down through friction - as a means of keeping the ice from melting?

Do a simple experiment. Rub your hands together for 15-20 seconds. Do they feel hotter? You're basically advocating turning kinetic energy into thermal energy. The ice is moving and you can't simply make that energy disappear. It has to go somewhere, and if you stop that ice from moving all you're going to do is create a good deal of heat.

The land stops the ice, the top few meters of the water surface can stop the flow.

Creating a situation where the arctic ice is contained in manmade basins/dividers would stop wind from blowing the ice out.

[Msalgado]

Yes, but you're not understanding that these huge masses of ice that are moving have huge amounts of kinetic energy. When you stop them (which I don't think is realistically possible) that kinetic energy has to go somewhere. Simple conservation of energy teaches you that. Removing that kinetic energy from the ice is going to change it over into thermal energy which is going to melt the ice right then and there.

Also, where the ice melts is really of little consequence as the whole atmospheric and oceanic circulation system is built on transferring excessive heat from the equatorial regions to the polar regions. Energy that is going into melting the ice at any location on earth will simply build up and you'll get a larger energy gradient. In the end, that energy is going to make its ways to the poles and melt that ice whether its north or south of the Fram.

[PhillipS]

I don't get all this talk about damming anything. Before anything else, if simple carbon cuts are not politically feasible how on earth is some large Geo engineering operation?

But besides all of that, it all comes down to simple conservation of energy. The melting of ice takes energy from one part of the earth system and moves it to another. If you are somehow able to stop the melting of the ice, all you do is build up the energy in other parts of the system. So you damn it up, and the ice doesn't flow out, but now oceanic heat that was melting the ice is now building up within the water and eventually the ice melts anyway.

I agree with you about geoengineering. All of the geoengineering proposals I've read about are terribly expensive, have side effects that are awful, and none of them address the underlying reality that finite fossil fuels are, well, finite and we will have to transition to renewable energy sources sooner or later. Unless a person believes that God will replenish the oilfields (watch

if you've never heard of 'abiotic' oil) and that the supply is infinite.

The only choice we have is whether we make the transition soon while we can preserve our economy and evnvironment, or whether we continue to burn coal and oil (BAU) until we've really soiled our nest and are stuck with crises in our food supplies, energy supplies, environmental disasters and national security.