I have read the relevant sections of the user guide (Interpreting Results, and the Model explanation) but I still have a question regarding CC.
Is it essentially the amount of heat mitigation that is being done in that pixel based on albedo, shade, and ET, but not including green area effects? Where 1 would be full heat mitigation and 0 would be no mitigation? And is it accurate to present the data like a percent? So, for example, if a pixel has a CC of 0.35, could you say that ~35% of the heat in that pixel is being mitigated (again, not accounting for any neighboring green space benefits)?
If not, then how would one describe this value to, say, a city manager?
Because the equation for cooling capacity is 𝐶𝐶𝑖 = 0.6 ⋅ 𝑠ℎ𝑎𝑑𝑒 + 0.2 ⋅ 𝑎𝑙𝑏𝑒𝑑𝑜 + 0.2 ⋅ 𝐸𝑇𝐼, you’re right that 𝐶𝐶 is dependent only on shade, albedo, and evapotranspiration, and will always be between 0 and 1.
This is only guaranteed if your Kc values are all between 0 and 1. They usually are, but I have seen a couple of sources that give Kc values > 1.
IMO, saying “35% of the heat is being mitigated” is inaccurate because CC does not measure heat. According to Wikipedia, absolute CC is measured in watts. The model uses a relative CC index which is unitless. If you’re interested in the change in heat, the estimated air temperature rasters in the intermediate folder would be a better measure of that.
Even if you do use temperature values, I would avoid talking about a percent change in heat. In a technical sense, 0 degrees does not mean 0 heat, and this is entirely relative to the arbitrary Celsius/Fahrenheit temperature scales that we use. And even if it was possible, a “100% mitigation of heat” is not at all desirable!
For both CC and temperature, I think it would be better to describe them relative to another value. For instance, you could use an average CC value from an undeveloped area outside the city as a reference. If that CC was 0.8 and the CC in an urban area was 0.2, you could say that “The cooling capacity index in the urban area is 25% that of the undeveloped area”.
If a pixel has a CC of 0.35, I think you could also say that “The CC index here is 35% of the maximum”. Again it would probably be more helpful to phrase this relative to a desired CC index. And because the 𝐸𝑇𝐼 is relative to the maximum 𝐸𝑇0 in the area of interest, I would make sure that your area of interest is representative and doesn’t have any strange outliers.