"No particles, no fog!" is the intriguing title of a new video clip just released on YouTube. The clip is by ASCOS Science Team member Zoran Ristovski at Queensland University of Technology in Brisbane, Australia. Click on http://www.youtube.com/watch?v=EneDwu0HrVg to watch it!
The background is the fact that cloud droplets cannot form unless there are tiny particles in the air that can act as embryos for the droplet formation. Nature most often handles this problem by providing particles and we normally don't have to worry about this limitation.
But not always! This film was shot towards the end of the ASCOS field expedition in the central Arctic summer 2008, on the Swedish icebreaker Oden. It illustrates an episode when the particle count was so low that cloud droplets just could not form; somthing that hardly happens in the midlatitudes but does happen in the summer Arctic.