I was looking through photos from Fractracker and had some questions!
Oil and gas drilling in ND. Photo by Nick Lund, 2014, via Fractracker Alliance
Many of the photos have this characteristic shimmering air. What causes this? This one, for instance, looks like clean-burning flame (i.e. no smoke) which suggests that whatever is being burned is being wholly converted with very little carbon or soot. I realized I had no idea what I was looking at.
- Heat haze (where you're seeing a refraction of light due to convection and temperature)
- Gas cloud (where you're seeing a refraction of light due to -- new molecules floating around?)
- Invisible smoke (where you're seeing -- refraction due to tiny particles? but that would just be haze)
I don't know much about how fire works.
I guess a related question is: Can you tell anything about a flare based on how dirty the smoke is?