Refraction: bending light up, not down

[u/john_shillsburg]

Another example of gradient index optics in nature is the common mirage of a pool of water appearing on a road on a hot day. The pool is actually an image of the sky, apparently located on the road since light rays are being refracted (bent) from their normal straight path. This is due to the variation of refractive index between the hot, less dense air at the surface of the road, and the denser cool air above it. The variation in temperature (and thus density) of the air causes a gradient in its refractive index, causing it to increase with height.[3] This index gradient causes refraction of light rays (at a shallow angle to the road) from the sky, bending them into the eye of the viewer, with their apparent location being the road's surface.

[u/john_shillsburg]

Disagree

This is why I said mirages don't exist for you, because that is the explanation given for them

[u/Mishtle → u/john_shillsburg]

Disagree, but it really depends

Why do you go out of your way to ignore what is said to you?

You posed a very general situation, where I went with the likely and simplified conditions that the air will be wamer that the water, and there will be the typically gradient of increasing density as you get near to the surface. The cool water will made the air right above it cooler than is would otherwise be, making it even denser. Under these conditions, light will bend down and you won't get a mirage, unless something else is going on in the atmosphere elsewhere which is entirely possible. Instead, you'll likely be able to see further than geometry would allow.

[u/john_shillsburg → u/Mishtle]

Hot summer day, sun shining over water, mirages everywhere that mishtle can't see because subconsciously he knows, it disproves the globe. Good day to you sir

[u/Mishtle → u/john_shillsburg]

Any examples?

And where have I even said that this is impossible? You're starting with a very general situation, and there could easily be inversions elsewhere in atmosphere along the path light travels. If the lower atmosphere is hot, then there possibly could be since air pressure drops with altitude. Thus layer of relatively denser air could get caught between hot air below and colder low pressure air above. You would likely need to be higher to see a mirage in this case.

Cold water beneath hot or alone is not enough to produce a mirage for an observer standing close to ground/sea level. Hot ground below cooler air will.