Urban wind flows deposit pollutants in repetitive patterns

Liat Clark, writing for Wired.co.uk:

As wind weaves through the everyday fumes generated by a city, it gathers particles from car exhausts, dust and other minute pollutants. Using a mathematical dynamical systems formula dictated by Lagrangian mechanics, the Arizona State University and University of Notre Dame team plotted the random motion of these particles for the first time. The model, built to simulate the wind motion over long periods of time, found that the process was not random at all—a coherent pattern rapidly emerged, demonstrating that the particles were repeatedly deposited in the same area. 

In addition to reducing pollution at the source, I would think such a model could guide tree planting efforts.

(Thanks to Michael Kenny.)

Thanks to the support of readers like you, Per Square Mile remains independent and ad-free.

If you enjoy what you read, please consider supporting the site with a donation.