Water vapor doesn't do anything. The sun doesn't change size (except for some distortion at sunrise and sunset due to refraction). It only seems larger when it is lower in the sky, and it is possible to compare it to surface features. High in the sky, there is nothing to compare it to.
Atmospheric lensing? Water vapors magnify the sun. The sun changes size all throughout the day in case you didn't know.
Water vapor doesn't do anything. The sun doesn't change size (except for some distortion at sunrise and sunset due to refraction). It only seems larger when it is lower in the sky, and it is possible to compare it to surface features. High in the sky, there is nothing to compare it to.