If polar ice melts will we have more or less heat from the sun?

The Polar Ice cap is at the mercy of the Atlantic Ocean during summer, currently the AMO is in a positive phase and Northern Sea Ice is running low when observed over the last 30 years. But when the AMO switches to a positive phase Northern Sea Ice will become thicker, and no feedbacks will change this behaviour. The amount of surface area of the entire Arctic Ice cap is at most 2 percent of the surface area of the planet. Any change of albedo of just a couple of percent of the surface of the planet cannot possibly modulate the global climate.

If the oceans are a perfect mirror, then I look like a dark nothing with white frothy edges. I guess that's OK 'cuz my wife looks the same.

If the oceans are a perfect mirror, then we can see nothing when we scuba or snorkle, because there is no light below the surface.

If the oceans are a perfect mirror ... well, obviously they are not. They absorb more light than they reflect at the surface.

For three or four months of the the Arctic will probably receive more solar heat, you have to remember the Arctic ocean would seldom be flat like a mirror, but the rest of the time heat will be flowing out of the Arctic ocean, the Arctic is different from most oceans as the deeper water is warmer and insulated by the ice on top.

So it is difficult to say if there would there be a net loss or gain.

One thing for sure there would a lot more snow falling on the Northern hemisphere as the Arctic would cause a lake snow effect.

" The reflectivity graph does not show what one observes."

That shows that you're not observing as closely as you think. 22 degrees from horizontal does indeed allow very significant amounts of light through. The "perfect mirror" effect you see from underwater comes when the reflected light from underwater is greater than the penetrating light. It's not near so rapid a switch as you perceive.

Edit: A quote very much a propos to your argument, from the second paragraph of the Wiki article:

" This can only occur where the wave travels from a medium with a higher refractive index (n1) to one with a lower refractive index (n2). For example, it will occur with light when passing from glass to air, but not when passing from air to glass."

http://en.wikipedia.org/wiki/Total_internal_reflec...

Hi Barry,

When incoming solar radiation hits the Arctic ice approximately half of it is reflected back into space. It varies from about 30% in the case of the dirty multiyear ice to 80% for newly formed ice and ice that is covered in fresh snow.

The underlying water is a significantly darker colour and so a lot more of the sunlight is absorbed, it’s about 92%.

This graphic shows the reflectance of some common surfaces:

http://en.wikipedia.org/wiki/File:Albedo-e_hg.svg

As the ice in the Arctic recedes it exposes more of the darker water and so more heat energy is absorbed, this causes further melting of the ice and a coupled feedback mechanism is established in which A leads to B leads to A leads to B etc.

As a result of this the Arctic has warmed significantly more than anywhere else on the planet, as shown in this graphic which shows the amount of warming over the last 30 years:

http://data.giss.nasa.gov/cgi-bin/gistemp/nmaps.cg...

Water is an unusual substance when it comes to reflectivity, it behaves differently from most other materials. Even when the Sun is relatively low on the horizon most of the solar energy will be absorbed, as shown in this graphic:

http://en.wikipedia.org/wiki/File:Water_reflectivi...

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RE: YOUR ADDED DETAILS

Thanks for the added details. As I mentioned, water is something of an oddity when it comes to reflecting light and that’s a consequence of the wavelengths of light within the visible spectrum. No matter how turbulent the water looks to us, from the perspective of a photon of light it is very smooth.

The consequence of this is that light is reflected specularly and not diffusely as one night expect. When the Sun is low on the horizon (the angle of incident light) there is reduced reflectance as a consequence of Fresnel reflectivity, namely the steepness of the reflectance angle versus the incident angle.

It’s explained in more detail here:

http://vih.freeshell.org/pp/01-ONW-St.Petersburg/F...

The Earth is a dust speck next to the Sun . Its a ball of fusion unaware of anything on Earth .

The amount of heat we get from the Sun is not influenced by how much ice covers the Earth. I think it is heat conversion and retention you are referring to.