ORIGINAL: Jimmy S
Yes, that is correct.
Inthe morning as the air is slowly heated, the air tends to rise, taking your scent with it.
Contrary, in the afternoon, before sunset, as the day cools down, the opposite happens.
This is exactly right.
This is the exact reason why I get so frustrated with people who clamor over Scentlock suits, etc. and say "a deer was directly down wind of me and he never knew I was there." It's because of the thermals carrying your scent up away from the ground. Unless you're in an air-tight bubble, if wind blows directly from you to the deer on the ground you're getting busted...period.
In hilly terrain, hunt high in the mornings and low in the evenings or the thermals will ruin your hunt every time.