Every Thursday morning at 11:30 AM during the ?Christopher Gabriel Show? on WDAY AM-970, I participate in a segment where we talk about and answer questions about the weather. Last week, a caller asked about what causes the distortion of objects during the winter.
During most of our cold season, the temperatures aloft are frequently warmer than those found near the surface, especially when there is snow on the ground. Because the air in this cold surface layer is denser, light from distant objects entering it bend in such a way that these objects can appear shifted upwards. This is referred to as a superior mirage. What this can do is make distant objects appear larger; for example; make a small rise appear to be a large hill or mountains appear to be even higher.
It can also make things beyond the horizon visible giving the illusion that those objects are much closer and sometimes larger than they actually are.