How is albedo change calculated?

[Trackman1997]

Albedo in Aurora is used differently, even if it refers to the same thing, in Aurora it’s multiplied by the base temperature and greenhouse effect to get final temperature, and is generally above 1 (though usually never more than 1. 1 from what I’ve seen, don’t know the actual limits though), so a real life albedo of 1 would be equivalent to an Aurora 4X albedo of 0, and I don’t know that there’s an equivalent to a real-life albedo of 0 as you can just increase the Aurora 4X albedo seemingly to infinity if we just go by the math while a true black-body would reach an equilibrium of radiating heat and incoming energy. 

[Iceranger]

I've tried searching for this, but it doesn't seem to be documented anywhere except for a paragraph on how it works in VB6:

The amount of albedo change is based on the extent of the ice sheet (F9 again) plus a random factor.

Is this still the case in C#? I've constructed a spreadsheet to calculate optimal terraforming, but as of now I need to recalculate when ice sheets melts. This would be unnecessary if I knew beforehand how the albedo would change :-)

When the ice melts, Albedo increases by 0.0015 * Hydro Extent.

Does this mean that if I add water vapor while the water is frozen I'll get a bigger Albedo increases when it melts?

Yes, although I probably should change it so that adding ice reduces Albedo.

Why would ice reduce Albedo?

Albedo is a non-dimensional, unitless quantity that indicates how well a surface reflects solar energy. Albedo (α) varies between 0 and 1. Albedo commonly refers to the "whiteness" of a surface, with 0 meaning black and 1 meaning white. A value of 0 means the surface is a "perfect absorber" that absorbs all incoming energy. Absorbed solar energy can be used to heat the surface or, when sea ice is present, melt the surface. A value of 1 means the surface is a "perfect reflector" that reflects all incoming energy.

Because albedo in Aurora is backwards. The larger it is, the more energy the body absorbs.

[steili (OP)]

I've tried searching for this, but it doesn't seem to be documented anywhere except for a paragraph on how it works in VB6:

The amount of albedo change is based on the extent of the ice sheet (F9 again) plus a random factor.

Is this still the case in C#? I've constructed a spreadsheet to calculate optimal terraforming, but as of now I need to recalculate when ice sheets melts. This would be unnecessary if I knew beforehand how the albedo would change :-)

When the ice melts, Albedo increases by 0.0015 * Hydro Extent.

Does this mean that if I add water vapor while the water is frozen I'll get a bigger Albedo increases when it melts?

Yes, although I probably should change it so that adding ice reduces Albedo.

I was just going to ask about this. Since the albedo doesn't decrease when water vapour desublimate into ice, you benefit from adding water vapour first (you should do this anyway to let it condense to water/desublimate to ice while you're adding other gases), since the albedo will increase when the ice sheet melts (at -17C?).

[TurielD]

I was just going to ask about this.  Since the albedo doesn't decrease when water vapour desublimate into ice, you benefit from adding water vapour first (you should do this anyway to let it condense to water/desublimate to ice while you're adding other gases), since the albedo will increase when the ice sheet melts (at -17C?). 

I can confirm this works as per 1. 12, and breaks Albedo.

To replicate, SM change the atmosphere of a planet to reduce its temperature, add hydro, then atmo change to raise its temperature.
The Albedo will increase.  You can repeat this to raise the albedo as high as you wish.
The reverse is also true - set hydro high, and atmo-reduce temperature.  Remove the hydro, re-set the atmo, and albedo lowers.

Titan is a good example - normally it cannot get into perfect habitable range - with max Greenhouse Factor, it can only reach a temperature factor of 0. 637. 
But if you add enough hydrographic extent (the perfect number is 42, of course) before you add greenhouse factor, then albedo will rise to 1. 063 which allows the temperature to reach -9. 6 degrees C.

[Froggiest1982]

I've tried searching for this, but it doesn't seem to be documented anywhere except for a paragraph on how it works in VB6:

The amount of albedo change is based on the extent of the ice sheet (F9 again) plus a random factor.

Is this still the case in C#? I've constructed a spreadsheet to calculate optimal terraforming, but as of now I need to recalculate when ice sheets melts. This would be unnecessary if I knew beforehand how the albedo would change :-)

When the ice melts, Albedo increases by 0.0015 * Hydro Extent.

Does this mean that if I add water vapor while the water is frozen I'll get a bigger Albedo increases when it melts?

Yes, although I probably should change it so that adding ice reduces Albedo.

I was just going to ask about this. Since the albedo doesn't decrease when water vapour desublimate into ice, you benefit from adding water vapour first (you should do this anyway to let it condense to water/desublimate to ice while you're adding other gases), since the albedo will increase when the ice sheet melts (at -17C?).

I was 100% sure to be -17C and apparently I was wrong. So after years of believing so Steve confirmed me on another post that ice melts at -27C.

I had to redo my spreadsheet because of that.