Can you imagine the snow-smell in the air? Have you ever heard anyone say "it smells like snow" or "I feel like it's going to snow today"? Are you one of those lucky people who can feel snow in the air? Could you tell last night that we were going to get this beautiful powder today, even without hearing a forecast? How is this possible? If you ask around, you are sure to find a range of people, old and young, scientist and amateur, who say they get a certain "smell" or "feel" hours before it snows. An online search will turn up dozens of discussions (like this one ) with people trying to put words to this snow sense. Words like fresh , crisp , wet , cold , sharp , and clean are used frequently. Others mention smelling "ozone," "metallicness," or "electricity." Some feel "compressed air" or a "muffleness," and some said they can feel it in their bones or sinuses. What exactly is going on? Some...