Vernier Oxygen and Carbon Dioxide Sensors Around a Campfire

I slowly walked around the glowing coals of a campfire tonight while holding Vernier oxygen and carbon dioxide sensors at about hip level.  The highs in the carbon dioxide readings correspond to lows in the oxygen readings, and these highs and lows correspond to when I was roughly east of the fire.  Though the wind was almost calm, it appears to me that the "smoke" from the fire was blowing toward the east.   I think under much more controlled circumstances this could lead to classroom/laboratory exercises in mapping plumes of gases from point sources.