By Tobias Carroll There are plenty of reasons to savor being outdoors in winter, but the experience of walking around on a snowy day is especially compelling. It is, as the saying goes, a treat for the senses — and that includes one’s sense of smell. The science behind why snow is an olfactory experience makes for interesting reading, and it relates to a complex interaction between the human body and the landscape around it. But if you’ve gone outside in the snow in recent years and thought that something smelled a little different than you were expecting, you weren’t imagining things. Instead…